Category Archives: Native Plants

Bees & Pollinators, Birds, Native Plants, Perennials, Uncategorized

Native Grasses Provide Winter Interest and Feed the Birds

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By Silvia Strobl, Master Gardener

This week I’ve been enjoying watching a flock of American Tree Sparrows that have migrated south from their summer tundra breeding grounds to my garden north of Peterborough for the winter. While I have both sunflower and nyger feeders, they are feeding exclusively on the Big Bluestem and Savannah Grass seeds in my garden. Sadly, these native grasses seem to have a bad rap among gardeners which is too bad as they have many benefits for both you and local wildlife.

I have the following four commonly occurring warm season perennial native grasses in my full sun garden:

Big Bluestem (Andropogon gerardii) is a very tall (5 – 8 ft) grass with clumps that form a dense sod but does not creep by rhizomes. It competes aggressively with shallow-rooted flowers, so it is best planted with species that form deep tap roots or spring bloomers that go dormant in the summer. In my garden it is a fall season focal point at the back of a border behind Culver’s Root (Veronicastrum virginicum) which has a central taproot as well as underground rhizomes.

In early May, Big Bluestem still hasn’t emerged, but allium foliage and some blooming tulips fill the space (left). By late June, alliums appear to float above the Big Bluestem grass (highlighted in orange) that is now 2 ft. tall (middle) and hiding the bulb foliage. By late July, Big Bluestem grass provides a green backdrop for the white flower spikes of Culver’s Root (right).

Little Bluestem (Schizachyrium scoparium) is an excellent grass for gardens due to its shorter height (2 – 4 ft), clumping form, very showy silver-white seed heads, and bright red stems in fall.It prefers dry sandy soils.

Savannah Grass (Sorghastrum nutans)is another tall grass (5 -7 ft) for the back of the border. It tends to self-sow so the young seedlings require a little annual weeding.

Native grasses add movement and colour to the garden. Little Bluestem’s red stems are illuminated by early October morning sun (left) while the late afternoon August sun highlights the tiny golden flowers and flower stalks of Savannah Grass (right).

Sideoats Grama (Bouteloua curtipendula) is a hardy, short bunchgrass that spreads very slowly by means of short, stout rhizomes and doesn’t compete with other plants. Its deep fibrous roots make it useful on slopes to prevent erosion (or on the edges of slightly sloped garden beds as in my garden). Do not plant it in clay soils.

Sideoats Grama has delicate hanging flowers (left), and later seeds (right) that are held in spikes that fall gracefully to one side of the stem.

Benefits for you

As well as being stunning fall and winter focal points, the tall native grasses, Big Bluestem and Savannah Grass, make excellent privacy borders. Their very deep roots (5-6 feet or more) make them useful for erosion control on slopes. Each of these native grasses is drought tolerant. And, each creates excellent winter interest as they tend to maintain their upright form. Another bonus is that they all have low palatability to deer.

Big Bluestem (left) and Savannah Grass (right) stand tall in the author’s garden despite 12 inches of winter snow.

Benefits for wildlife

Many butterfly skipper and moth larvae feed on these native grasses and they provide critically important seeds and habitat for native birds in fall and winter.

An adult Delaware Skipper rests on a blade of Big Bluestem in the author’s garden (left). Big Bluestem is a host plant for this butterfly’s larvae. Both Little Bluestem and Sideoats Grama are host plants for Leonard’s Skipper caterpillars. The adult butterfly is seen here nectaring on marigold in the author’s garden (right)

American Tree Sparrows feeding on a buffet of Big Bluestem (left) and Savannah Grass (right) seeds in the author’s garden. It is fun to watch them “ride” the Savannah grass stems to the ground so they can more easily peck at the seeds some of which spill onto the fresh snow.

Native Grass Establishment and Maintenance

Most native plant nurseries stock these grasses and all of them are easily propagated from seed. Plant seedlings densely at 1 ft to 1.5 ft spacing to discourage weeds. Water during the first year while roots are getting established. Fertilization is not necessary. All can be easily divided, but Sideoats Grama should be teased apart, not cut with a spade.

Remnant pockets of native grasses like this one of Big Bluestem growing on the shoreline of Little Jack Lake (left) are good places to collect seeds to propagate your own plants (right). Never collect more than 10% of seeds.

Depending on how much seed the birds eat in winter, you might get a few volunteer seedlings. If you don’t want more plants, they are easily kept in check by weeding when they are small.

If weedy cool season grasses have seeded into native warm season clumps, use a propane torch in early spring to burn emerged leaf blades while warm season native grasses are still dormant. Be sure to first cut off last year’s dry stalks and have a hose nearby. Don’t do this on a windy day!

Big Bluestem, Savannah and Little Bluestem are 3 of the 4 dominant grasses found in remnant tall grass prairies and oak savannahs, of which less than 1% of their pre-European settlement extent remains in Ontario. (The other is Switchgrass (Panicum virgatum) which can self sow quite a bit so might not be suitable for small gardens.) These grasses are also found on dunes, sandy shorelines, rock barrens, roadsides, and hydro corridors. Including these grasses in your garden can help support some of the wildlife that rely on this endangered ecosystem.

REFERENCES & ADDITIONAL RESOURCES

Diboll, N and H. Cox. 2023. The Gardener’s Guide to Prairie Plants. Pages 302-303, 306-307, 326-329.

Ehrlich, P. R. D.S. Dobkin and D. Wehte. 1988. The Birder’s Handbook A Field Guide to the Natural History of North American Birds, The Essential Companion to your Identification Guide. Page 584.

Johnson, L. and S. Colla. 2022. A Garden for the Rusty-Patched Bumblebee—Creating Habitat for Native Pollinators. Pages 149, 150, and 159.

Map of Native Plant Nurseries in Ontario maintained by Halton & Area Master  Gardeners

North American Native Plant Society. 2017. Seed collecting and saving.

RELATED

GARDENING FOR BIRDS THROUGH THE SEASONS

A FEW OF MY FAVOURITE NATIVE PLANTS

EXPANDING YOUR NATIVE PLANT PALETTE

WINTER FAVOURITES

Communication, Garden rejuvenation, Native Plants, Natural Fertilizers

Dynamic Accumulators: Useful plants for both lazy and nerdy gardeners

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By Rachel Foebel, Master Gardener in Training

What are dynamic accumulators?

These are plants known to collect large amounts of soil nutrients, usually from deeper in the soil via long tap roots (sometimes fibrous roots as well) and store them within the plant. These plants are used to then release their nutrients to the upper layers of the soil as the above ground parts of the plant break down, either by harvesting, winter, or completion of a life cycle. The most known and used plants tend to be Common Comfrey (Symphytum officinale) or Russian Comfrey (Symphytum x uplandicum) and sometimes plants from the nettle family such as stinging nettle (Urtica dioica). Additionally, cover crops such as legumes are used widely to serve this same purpose. Dandelions and rhubarb are also known to be dynamic accumulators.

Left: Comfrey picture (caption: Common comfrey (Symphytum officinale)
Right: Comfrey flower (caption: Comfrey flower)

Is there any science to back this up?

While this method of soil improvement has been discussed and used for a while (since the 1980’s), research to prove this concept has only begun to occur very recently.

In 2020, Northeast SARE (Sustainable Agriculture Research and Education) provided a research grant to Unadilla Community Farm, in coordination with Cornell University, “to help expand our collective understanding of what exactly dynamic accumulators are, how they work, and what are some practical applications for these plants,” (Zarro, 2020). For the purposes of their work, a dynamic accumulator was defined as a plant containing roughly 200% of the set average of any of the 20 beneficial nutrients they had data for (Tyler, 2022). They were able to identify over 340 plant species that qualify based on these terms and created a dynamic accumulator online database.

Here is where you can find this database: https://docs.google.com/spreadsheets/d/19S3wsjXU6VPzmbklZLVxKt6DCyZIPjCYw6zRrVg7M4Y/edit?pli=1&gid=1519867200#gid=1519867200

Add picture:

A clip of the database to show how it displays its information about each nutrient

And here is where you can find more information on the methods they used to compile the database: https://smallfarms.cornell.edu/2022/04/new-findings-further-the-study-of-dynamic-accumulators/

The work done since the database was formed has given more insight still. It has been found that these plants cannot perform to the level they are expected on the database unless these nutrients exist somewhere in the soil to begin with. While this seems obvious, it means that you can’t expect these plants to fully restore poor soil on their own. They can only be one part of the plan or be used to maintain soil that already has some nutrients to share.

Are there dynamic accumulators that are native to Ontario?

Yes. Some examples are paw paws, blue cohosh, wild strawberries, self heal. To find more you can cross reference the above-linked dynamic accumulator database with a native plant database like this:

https://networkofnature.org/species/

Or this:

Plant Database

Wild Strawberry (Fragaria vesca)), Self heal (Prunella vulgaris))

How do I fit this into my garden practices?

Some of these will arise on their own, like clover, lamb’s quarters, dandelions, etc. If they have not gone to seed, simply pull them like you would any weed and let them decompose on top of your garden soil. Alternatively, you can bring them to your compost bin to release their nutrients there. If they are a desired species, you can plant them right where you need them most. You can plan them into your vegetable crop rotations if they are annuals. The commonly used perennial comfrey re-grows quickly, so the foliage can be removed and used as mulch nearby. Planted under a fruit tree, you can let the process occur on its own each year as the foliage on top dies in winter and feeds the soil that way. This is a common permaculture practice that now finally has some research to back it up!

A permaculture-style vegetable garden

References

Tyler, Ben. (April 3, 2022). New Findings Further the Studies of Dynamic Accumulators. Cornell College of Agriculture and Life Sciences. https://smallfarms.cornell.edu/2022/04/new-findings-further-the-study-of-dynamic-accumulators/

Zarro, Greta. (July 20, 2020). Breaking Ground with Dynamic Accumulators. Cornell College of Agriculture and Life Sciences. https://smallfarms.cornell.edu/2020/07/breaking-ground-with-dynamic-accumulators/

Tyler, Ben & Zarro, Greta (Dec 2021). A dynamic accumulator database and field trials for six promising species. Northeast Sustainable Agriculture & Research Education.  https://projects.sare.org/wp-content/uploads/A-dynamic-accumulator-database-and-field-trials-for-six-promising-species.pdf

Some other interesting articles on Dynamic Accumulators:

Kitsteiner, John. (April 15, 2015). The Facts about Dynamic Accumulators. Permaculture Research Institute. https://www.permaculturenews.org/2015/04/10/the-facts-about-dynamic-accumulators/

James, Sean. (2011). Permaculture, the art of edible gardening. Landscape Ontario.com https://landscapeontario.com/permaculture-the-art-of-edible-gardening

Battersby, Sarah (2009). Love Your Dandelions, They’re Dynamic! Toronto Gardens Blog. https://www.torontogardens.com/2009/04/love-your-dandelions-theyre-dynamic.html/

Advice, Garden Design, Native Plants, Perennials, Planting, Shrubs & Trees

Fall is the New Spring…It’s Time to Plant

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by Emma Murphy, Master Gardener

I confess to LOVING this time of year. The heat and humidity of the summer is gone, and our gardens are still looking lovely. Although my established gardens are beginning the slow process of fading and getting settled in for their winter sleep, fall is a wonderful time to plant for so many reasons.

They may not look perfect but they’ll be going to sleep soon and will wake up next spring in their new homes.

You Have Time

Unlike your annuals or tender perennials, most perennials (and native plants in particular) can be planted in September and well into October (depending on where you live in Ontario).

Smaller trees and shrubs in particular are fine to plant once they have gone dormant and leaves have dropped, as long as they are well watered until freeze up.

I love the fall as it seems less frenzied than the spring gardening season, with time to reflect on the summer that has passed. Unlike spring and summer, temperatures moderate during fall, not only for the plants but also for us! It’s terrific working weather – you start with your sweatshirt on in the morning, but by the afternoon the temperatures have warmed up considerably and you might be in a t-shirt. During July and August I can only work in my gardens in the early morning or late evening due to the heat. Your plants don’t like to be planted in the heat of summer either. So fall is my happy time.

Assessing and Dividing

Fall is the perfect time to look around your garden – do you have holes, bad-looking spots, poorly performing plants? Are there places that need something new or something moved?

I need to revamp this garden and think about moving some perennials around.

Fall is a great time to divide overgrown perennials, especially those that bloom in the spring. I just dug up all of my fragrant hostas the other day and moved them to a new location so that I can expand my shade native plant garden. Next up – planting a hedgerow.

Hostas at the front of the bed were removed to put in more native plants

Warmer Soil Temperatures

During fall, soil temperatures remain warm from the summer sun, so conditions are ideal for root growth.

Cooler Air Temperatures

Gone is the humidity and heat of the summer and the unpredictability of spring weather (and worries about frost). Daytime high temperatures are nice and there is less water evaporation from leaves.

More Rain, Less Work

With fall also comes more frequent rainfall and less need to water new plantings. There aren’t crazy swings in moisture levels – fall rains are warm and welcome and moisture levels are perfectly balanced, encouraging root growth.

When you plant in spring and early summer, the weather can be very variable, especially with regard to temperatures and rainfall. The soil is still cool, and plants take a while to get established.

Fall rains rejuvenate our gardens

Some Challenges

It can be challenging to plant new perennials in the fall – stock and selections at nurseries may be less (however the prices may be better!) and some plants have been sitting in plastic pots for months and look less than perfect. Be sure to purchase new plants at a nursery that takes good care of their plants over the gardening season (that generally does not include big box stores – shop local where you can) and pull the plant out and check for a healthy root mass in the pot.

Ideally, give your plants at least 6 weeks of optimal growing weather of fall before the colder winds start blowing in.

One Last Note

It’s a really good idea to add mulch to your fall gardening – it helps insulate the ground and maintains warm soil temperatures even during early winters. So, you are providing a nice warm area for young plants to establish their root systems before the frost.

A Special Note on Native Plants

They might look a little sad in the nursery, with not much top growth and it may be browning. However, under that soil are roots, lots of roots, and that is what you are buying when you purchase a native plant.

Although a bit brown on top, this native plant has great roots
just ready for a new home.

So when you see a small three inch plant with roots coming out the bottom, recognize that it’s the perfect size to plant, and don’t worry about its ability to survive the winter.

Sleep, Creep, Leap

You may have heard the phrase “sleep, creep, leap” with respect to many plants, and especially native plants. Unlike most perennials, native plants just want to get their roots established during the first year (which is why they appear to ‘sleep’).

So if you plant in the fall, the roots are growing furiously, pushing south to grab moisture and nutrients to sustain them through the heat of summer next year. In the second year native plants creep, with more top growth and maybe even flowering. Watch out in the third year! They leap to their full size and blooming capacity.

So, if you can plant in the fall, the sooner your native plants can put down their roots in their new home, and be ready to grow in the spring season.

Bottom line? Fall weather is optimal for growth.

The perfect combo of warm soil temperatures near the root and cooler air temperatures on the top offer the ideal growing conditions for any new plantings or dividing existing perennials.

So get out in your gardens! (It’s also time to think about planting your spring flowering bulbs. Check out Master Gardener Cheryl Harrison’s excellent blog on how to do this.

Advice, Native Plants, Shrubs & Trees

Garden Jeopardy: The Small Native Tree Edition

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By Lois Scott, Master Gardener

Welcome to the second edition of Garden Jeopardy featuring a number of smaller native trees. 

I do love trees and in my suburban garden the opportunity to grow multiple smaller varieties is appealing.  The choices are many and discovering an interesting characteristic or benefit about a particular species inspires my choices.  Hopefully this edition will be inspiring for gardeners looking to add more trees to their gardens this fall.  You can confirm your responses at the end.

  1.  A shade-tolerant tree with smooth, blue-tinged bark and a fluted trunk sometimes known as ‘musclewood’.
  2. A tree that bears white, showy clusters of flowers in June or July that develop into orange or red fruits that are persistant throughout the winter and much loved by birds.
  3. A small evergreen tree that is resistant to insects and rot, rarely requires pruning and produces dark blue, berry-like cones that are a food source for Cedar Waxwings.
  4. A species at risk tree for part to full shade that is a host tree for the Giant Swallowtail butterfly, the largest butterfly found in Canada.
  5. An understory tree with branches in distinct layers that produces clusters of white flowers in spring, red leaves in the fall and is an important butterfly larval host.
  6. A tough, adaptable and urban friendly tree with a distinct upright trunk, wide-spreading crown and the densest Canadian wood.
  7. A tree bearing pea-flower shaped intense pink flowers in spring prior to leafing out, that is not native to Peterborough but will thrive here in a protected area.
  8. An excellent Peterborough source for the aforementioned trees.
A bedraggled Giant Swallowtail in my garden.

  1. What is the Blue Beech; Carpinus caroliniana?
  2. What is the American Mountain Ash; Sorbus americana?
  3. What is the Eastern Redcedar; Juniperus virginiana?
  4. What is the Common Hoptree; Ptelea trifoliata?
  5. What is the Alternate-Leaf Dogwood; Cornus alternifolia?
  6. What is the Ironwood, Hop-hornbeam; Ostrya virginiana?
  7. What is the Redbud; Cercis canadensis?
  8. What is Ecology Park Native Plant Nursery?  https://greenup.on.ca/ecology-park/
Pagoda Dogwood in fall.

Thank you for participating in this edition of Garden Jeopardy!  For information on tree planting please check out MG Cheryl Harrison’s blog on planting trees which includes a link on how to properly plant a tree. https://peterboroughmastergardeners.com/2024/04/22/earth-day-2024-plant-a-tree/

Native Plants, Perennials, Shade Gardening

Underfoot & Under-Valued? The Common Liverwort

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By Mary-Jane Pilgrim, Master Gardener

Umbrella liverwort (Marchantia polymorpha) is a fascinating plant that often catches the eye with its unique, umbrella-like structures. These small, flat, and green plants have been around for millions of years, making them one of the oldest plant species on Earth. They do not have a vascular system, and like ferns, they produce spores instead of seeds. While they do not flower, the female reproductive structures mature to look like tiny palm trees or umbrellas. For this reason, the common variety is called umbrella liverwort.

In our area, umbrella liverwort is commonly found in moist, shaded areas like garden beds, greenhouses, and along stream banks. This plant is native to many parts of the world, including Ontario, and has a long history of thriving in damp environments.

While liverwort is native, it can sometimes behave like an invasive plant, especially in gardens and greenhouses. It thrives in conditions where moisture is abundant, and air circulation is poor. If left unchecked, it can spread rapidly, covering the soil surface and competing with other plants for light and nutrients. However, its unique appearance and ancient history make it a cool plant to observe in your garden.

If you want to manage umbrella liverwort, focus on improving drainage, reducing moisture levels, and allowing more sunlight into the affected areas. But for those who appreciate its prehistoric charm, umbrella liverwort can be a delightful addition to a garden, provided it’s kept in check. An added benefit is that you don’t have to plant them — they just show up!

Bees & Pollinators, Butterflies and Moths, Native Plants

Want to help Monarchs? Plant Swamp Milkweed!

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By Silvia Strobl, Master Gardener in Training

My 2023 garden gave me a front row seat for observing the monarch butterfly (Danaus plexippus) lifecycle. Two monarch caterpillars fed on my garden’s swamp milkweed (Asclepias incarnata) lower leaves for about 10-12 days.  I was very concerned when one started a long journey across the 10-foot-long patio and then climbed 10 feet up the house wall to make its chrysalis just under the eaves! I was relieved to read that monarch caterpillars typically do leave their host plant to make their chrysalis elsewhere just in case there are younger caterpillar instars feeding on the same plant. It would be tragic if their chrysalis came crashing down as another caterpillar feeds on the leaf from which it is suspended!

One of the two caterpillars in my garden last year feasting on swamp milkweed on August 8. By August 13, many more swamp milkweed leaves at been eaten (right)

I expectantly watched the “eaves” chrysalis daily and was rewarded on September 5th when the green and gold flecked chrysalis became more translucent with visible orange and black inside. An adult male, identified by the two dots on its hindwings (pheromone patches), emerged later that day.

One monarch caterpillar travelled across the patio and climbed up the house wall to make its chrysalis just under the eaves on August 17 (left). On September 5, the chrysalis became translucent, and the butterfly emerged. It dried its wings for a few hours (centre). Once it opened its wings, I could identify it as a male by the two pheromone patches on its hindwings (right).

I never saw the second caterpillar leave the swamp milkweed host plant but discovered its chrysalis suspended from the leaves of savannah grass (Sorghastrum nutans) one day.

Swamp milkweed is a common species in Ontario, usually found in wetlands, wet roadsides, floodplains and wet meadows, but looks beautiful in the garden with its upright stature and slender leaves. Its flowers also bloom for a long time and are floral and vanilla scented. It grows quite tall and maintains its structure well into the winter months to provide winter garden interest.

Swamp milkweed is a better choice for the garden than common milkweed (A. syriaca) which is not recommended for small gardens due to its rhizomatous aggressive spreading nature. Although butterfly milkweed (A. tuberosa) is a great nectar plant it is also a less desirable monarch caterpillar food due to its hairier leaves and lower protein content (UNC Charlotte Institute 2022). Both swamp and common milkweed averaged the highest number of eggs laid by female adult monarch butterflies in a study that evaluated the attractiveness of nine milkweed species common to Iowa (Pocius et al. 2018).

Typical habitat for swamp milkweed in the wild, but “it is fairly drought tolerant and will thrive in drier areas once established” (Gray and Booth 2024) (left). A 2-year-old swamp milkweed plant in my dry, sandy garden (right).

Well-intentioned people hope to increase the monarch population by home-rearing monarchs. However, an analysis of over 135,000 monarch observations at 403 annual butterfly count locations across the species’ large summer range[1] compared population numbers in 1993 to those from 2018 and found that although some areas had population decreases, overall summer monarch population numbers in North America are relatively stable i.e., reproduction in summer is compensating for losses at wintering grounds in Mexico (Crossley 2022).

A naturally occurring parasite (Ophryocystis electroscirrha) adversely affects how well monarchs fly as well as their migration survival. It has increased in the last 15 years, raising concerns that parasite transmission is decreasing winter colony populations (Majewska et al., 2021). The Xerces Society has published a joint statement against the release of purchased or mass-reared monarchs by backyard and commercial breeders. If you are raising small numbers of wild-collected monarch eggs and larvae for personal enjoyment, education, or as part of citizen science project they encourage you to follow protocols for safe rearing and collect data on your reared monarchs for programs such as the Monarch Larva Monitoring Project and Monarch Health.

Although the research is not definitive, I recommend letting nature take its course and simply providing for the monarch caterpillar’s habitat needs by planting host plants, particularly swamp milkweed, in your garden.  This spring I planted two more patches of swamp milkweed plants in my garden. I can’t wait to observe the monarch caterpillar drama that unfolds this summer!

[1] The NA monarch breeding range spans nearly the entire United States and southern Canada. Butterfly counts by citizen scientists are held between July 1 and August 31.  Only data with at least 5 years of Monarch observations over a 10-year period were used in the Crossley (2022) analysis. An average of 25 butterfly counts are held annually in southern Ontario. Each count covers a 24-kilometer diameter circle. Last year I participated in my first count in Haliburton, Ontario.

Tips for growing swamp milkweed in your garden

  • If space allows, plant a group of 3 to 5 plants so pollinators can more easily find the flowers. It can grow in sand, loam or clay and prefers full sun.
  • You can grow your own seedlings by winter sowing or purchase seedlings from Ontario native plant nurseries.
  • Water consistently during the first year so swamp milkweed can build roots to support flowering in year 2.
  • Remove seed heads before seed pods open if you want to control the number of volunteer seedlings.
  • Swamp milkweed is not palatable to deer.

References

Crossley, M.S., T.D. Meehan, M.D. Moran, J. Glassberg, W.E. Snyder, A.K. Davis. 2022. Opposing global change drivers counterbalance trends in breeding North American monarch butterflies. Global Change Biology https://onlinelibrary.wiley.com/doi/full/10.1111/gcb.16282

Gray, R. and S. Booth. 2024. The Gardener’s Guide to Native Plants of the Southern Great Lakes Region. Firefly Books. 352 pp.

Marinelli, J. 2024. Rethinking Monarchs: Does the Beloved Butterfly Need Our Help? Yale Environment 360, Yale School of the Environment. https://e360.yale.edu/features/monarch-butterflies-milkweed-home-breeders

Majewska, A. A., Davis, A. K., Altizer, S., & Roode, J. C. (2021). Parasite dynamics in North American monarchs predicted by host density and seasonal migratory culling. Journal of Animal Ecology, 2022, 1–14. https://doi.org/10.1111/1365-2656.13678

Pocius, V.M., J.M. Pleasants, D.M. Debinski, K.G. Bidne, R.L. Hellmich, S.P. Bradbury, and S.L. Blodgett. 2018. Monarch Butterflies Show Differential Utilization of Nine Midwestern Milkweed Species. Front. Ecol. Evol., 24 October 2018 https://www.frontiersin.org/journals/ecology-and-evolution/articles/10.3389/fevo.2018.00169/full

UNC Charlotte Institute. 2022. Milkweeds for Monarchs? The Answer isn’t so simple. https://ui.charlotte.edu/story/milkweed-monarchs-answer-isne28099t-so-simple/

Related

The Kiss Principle—Winter Sowing 101 https://peterboroughmastergardeners.com/2022/12/26/the-kiss-principle-winter-sowing-101/
 

Annuals, Bees & Pollinators, Butterflies and Moths, Native Plants, Planting

Annuals in a Pollinator Garden?

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by Laura Gardner, Master Gardener

If you’re thinking of creating a pollinator garden with native perennial plants, there will be a period where your space will be rather underwhelming or undeveloped.

There is a saying, “first year they sleep, second year they creep, and third year they leap.” In the first year of their growth, many native plants focus channeling their energy into root development instead of flowering. It is important to consider other ways to increase floral resources for pollinators while you wait for these plants to grow.

Consider adding a few native species that are short-lived annuals or biennials—either potted plants or directly sown seed. If started early in the spring, Black-Eyed Susan (Rudbeckia hirta), for example, will bloom in the first year. It usually produces enough seed to ensure future generations.

Spotted Horsemint (Monarda punctata) and Lanceleaf Coreopsis (Coreopsis lanceolata) are a couple of others that will also bloom the first year when started early. Near-native annual sunflowers (Helianthus annuus) are another great choice for new pollinator gardens. An important consideration for choosing annual sunflowers is to make sure that they are not pollenless types.

Image source: https://commons.wikimedia.org/wiki/File:Coreopsis_lanceolata.jpg

That said, there really are not a whole lot of native annual species that you can add. To help fill in the gap, it is possible to consider some non-native annuals. An aspect of this that is concerning is whether these plants provide adequate nectar and/or pollen to pollinators.

Many annuals have been bred for size, colour, vigour, and length of bloom period and not so much for their nectar and pollen production. When I visit a garden centre, I pay attention to see if there are any insects visiting the plants. I usually don’t see a whole lot of activity. Of course, this is anecdotal, so what does the research say?

From my cursory reading, the research is a bit uneven. A UK study in 2017 found that most ornamental flowering plants found in garden centres were unattractive to pollinators.[i]

Another US study that looked at a select group of annuals found that while native plants were superior overall, there were some non-native annuals that could be important forage for pollinators. It was found that in comparison with Zinnia, Marigold (Tagetes), Lantana, and Starcluster (Pentas), Sweet Alyssum (Lobularia maritima) was the top performer. In particular, the cultivars “Frosty Knight” and “Snow Princess” showed the greatest diversity and abundance of pollinators compared to the other Lobularia types as well as the other species.[ii]

This year I planted some Lobularia near my vegetable garden in the hopes of attracting beneficial parasitic wasps. The adult wasps will seek out the nectar from the flowers and look for caterpillars on my Brassicas for their young.

Image source: “”Sweet Alyssum” by Mustang Joe is marked with CC0 1.0. To view the terms, visit https://creativecommons.org/publicdomain/zero/1.0/?ref=openverse.

Another more recent study from June of this year also found that while the native plants in the study were visited more by pollinators than the non-native plants, there were still some desirable non-native annuals. Specifically, Begonia and Impatiens were visited more frequently by pollinators than Pansy, Petunia, New Guinea Impatiens, and Geranium.

Similar to the previously mentioned study, these researchers found that there was variability between cultivars of a species. Of the cultivars, the four most visited were Begonia ‘Cocktail Brandy’, Begonia ‘Ambassador Rose Blush’, Impatiens ‘Accent Coral’, and Impatiens ‘Super Elfin XP White.’[iii]

Now, an important question that comes out of this is whether these plants provide quality floral resources for pollinators. Pollinator visits to flowers does not necessarily mean that they are benefiting from the resource. More research is needed in this area. Until then, we can make a few reasonable annual plant choices to help in the interim while the other plants in our new pollinator gardens mature.

[i] Garbuzov, Mihail & Alton, Karin & Ratnieks, Francis. (2017). Most ornamental plants on sale in garden centres are unattractive to flower-visiting insects. PeerJ. 5. e3066. 10.7717/peerj.3066.

[ii] E Erickson, S Adam, L Russo, V Wojcik, H M Patch, C M Grozinger, More Than Meets the Eye? The Role of Annual Ornamental Flowers in Supporting Pollinators, Environmental Entomology, Volume 49, Issue 1, February 2020, Pages 178–188, https://doi.org/10.1093/ee/nvz133

[iii] David Smitley, Colin Oneil, Erica Hotchkiss, Erik Runkle, Jared Studyvin, Evaluation of the most popular annual flowers sold in the United States and Europe indicates low visitation rates by pollinators and large variation among cultivars, Journal of Economic Entomology, Volume 117, Issue 3, June 2024, Pages 1057–1070, https://doi.org/10.1093/jee/toae084

Native Plants, Research, Seeds

Some Observations on Seeds

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Laura Gardner, Master Gardener

Ancient Seeds

Back in the 1890s, the mouth of the Don River in Toronto was filled in to make way for industry—known as the Port Lands. This changed the landscape and the plants that used to grow there “disappeared.” In 2021 while the site was being ecologically restored as part of the Port Lands Flood Protection Project, workers discovered some unusual plants that had sprouted shortly after seven metres of soil had been excavated. They were thought to be different than the usual species seen at the site.[i] Researchers at the University of Toronto began working to identify the species of plants and seeds found.[ii] Some of the plants included Schoenoplectus (Bulrush), Typha (Cattail), Salix exigua (Coyote Willow), Equisetum (Horsetail), as well as mosses and liverworts. Research is still ongoing as they seek to verify whether these plants came from an ancient seed bank. Through carbon dating, the research team was able to determine that some of the seeds from soil samples were between 150-400 years old! So far, most of the seeds that have been identified were from the Cyperaceae (Sedge) family with the majority in the Carex (True Sedges) genus followed by Schoenoplectus (Bulrushes), Sparganium (Bur-Reed) and Typha (Cattail).[iii] This is all very exciting because it shows that while some urban environments may be drastically altered, they are not necessarily permanently altered, and we may be able to successfully restore such landscapes to their pre-industrialized states.

Seed Dispersal and Physical Dormancy

Most seeds are known to be “physiologically dormant.” This means that they have an internal inhibiting mechanism (“endogenous”) that requires exposure to certain conditions to break dormancy (e.g. light, temperature, etc.).[iv] “Physically dormant” seeds have an external inhibiting mechanism (“exogenous”)—a hard coating that inhibits germination unless it becomes permeable–allowing water to enter, and then germination is initiated.[v] Some years ago, I planted a Zebrina Hollyhock Mallow (Malva sylvestris) in my garden. It is considered a biennial or a short-lived perennial. It bloomed but didn’t come back the following year and no new plants emerged from any possible dispersed seeds. It was not until about five years later that two plants emerged—about four metres away from the original plant site. These seeds are quite hard and require some form of natural scarification to break their seed coats. Scarification can occur through fluctuations in temperature, damage by gardening tools, damage by microorganisms, fungi, or animals; or transit through animals’ digestive tracts.”[vi] Myrmecochory could possibly explain the transfer of the seed from one location to another as seeds in the Malva family are frequently targeted by ants.[vii] In myrmecochory, ants transport the seeds and then remove and eat a nutritious coating from the seeds called the elaiosome.  Sometimes when the elaiosome is removed, the seed coat becomes thinner, and this enables water to enter. However, Baskin and Baskin suggest that removal of the elaiosome by ants on seeds like this may not influence the seed’s ability to imbibe moisture.[viii] 

Photo Credit

“Malva sylvestris sl27” by Stefan.lefnaer is licensed under CC BY-SA 4.0.

Recalcitrant[ix] or Hydrophilic[x] Seeds

When I think about some of the plants I grew from seed last year, I recall one species that did not have good germination—Geranium maculatum (Wild Geranium). There are different causes for poor germination, but one possibility is that the seed was not fresh enough or that their moisture content was not sufficiently retained. I learned that this species is somewhat recalcitrant or hydrophilic. These types of seeds are sensitive to drying and as time progresses, the percentage of seed death increases. William Cullina, in Wildflowers: A Guide to Growing and Propagating Native Flowers of North America, recommends sowing Geranium maculatum immediately upon harvest of the seeds in the summer. However, germination may be successful with seeds stored in plastic for 4-6 months—perhaps indicating this species inclination towards being partially recalcitrant.[xi] According to Dr. Norman Deno in Seed Germination Theory and Practice, Geranium maculatum is best sown in the summer from fresh seed and then is exposed to winter temperatures before germinating in the spring. Seeds are mostly dead when kept in dry storage for more than 6 months.[xii] One of the lessons learned here is to research the germination requirements thoroughly as well as inquire about the storage conditions/age of the seed before obtaining seed of a recalcitrant species from a supplier.

Heteromorphic or Dimorphic Seeds

Although considered a composite species, Bidens frondosa (Devil’s Beggarticks), usually lacks ray flowers and only has disk flowers. As a result, they are less attractive to pollinators than the other Bidens species.[xiii] It also has a weedier reputation. Being an annual, each plant can produce around 1,200 seeds that are viable for 3-5 years. The seed is a two-barbed achene that can stick to clothing and pet fur. Interestingly, the achenes are known to be heteromorphic or dimorphic in nature—there are two different kinds. Those produced on the periphery are black, thicker, and are less dormant than the ones produced in the middle. Those in the middle are brown, elongated, and are more dormant than the others. This is an example of how a plant has a particular way of increasing its rate of reproductive survival—the less dormant achenes fall close to the mother plant and germinate the following year while the ones that are more dormant are carried by animals (“epizoochory’) or by wind (“anemochory’) to germinate at different times in new environments.[xiv] These seed features help explain the resiliency and ability of this species to proliferate.

Photo Credit

Richard Frantz Jr., Public domain, via Wikimedia Commons. https://upload.wikimedia.org/wikipedia/commons/e/ef/Beggarsliceseeds.jpg

Photo Credit

Tephrosia virginiana (Goat’s Rue) seeds germinating

Resources

[i] Waterfront Toronto. 100-Year-Old Seeds. Online: https://www.waterfrontoronto.ca/news/100-year-old-seeds

[ii] University of Toronto. In the Media: Shelby Riskin discusses her research on ancient seeds found at the Don River. Online: https://eeb.utoronto.ca/2023/10/in-the-media-shelby-riskin-discusses-her-research-on-ancient-seeds-found-at-the-don-river/

[iii] Riskin, Shelby. Email communication (December 2023).

[iv] Willis, C.G., Baskin, C.C., Baskin, J.M., Auld, J.R., Venable, D.L., Cavender-Bares, J., Donohue, K., Rubio de Casas, R. and (2014), The evolution of seed dormancy: environmental cues, evolutionary hubs, and diversification of the seed plants. New Phytol, 203. p. 301. https://doi.org/10.1111/nph.12782

[v] Baskin, Carol C. and Jerry M. Baskin. Seeds: Ecology, Biogreography, and Evolution of Dormancy and Germination. 2nd Edition. 2014. p. 72.

[vi] Ansari, O., Gherekhloo, J., Kamkar, B. and Ghaderi-Far, F. (2016), Seed Sci. & Technol., 44, 3, p. 11. http://doi.org/10.15258/sst.2016.44.3.05

[vii] Baskin and Baskin, p. 681.

[viii] Ibid., p. 682.

[ix] Ibid., p. 8.

[x] Ontario Rock Garden and Hardy Plant Society. Hydrophilic Seeds will not Survive Dessication. Online: https://onrockgarden.com/images/Seedex/ABOUT_HYDROPHILIC_SEEDS.pdf

[xi] Cullina, William. Wildflowers: A Guide to Growing and Propagating Native Flowers of North America. 2000. p. 254.

[xii] Deno, Norman C. Seed Germination Theory and Practice. 2nd Edition. 1993. p. 148.

[xiii] Hilty, John. Illinois Wild Flowers. Online: https://www.illinoiswildflowers.info/wetland/plants/cm_beggarticks.htm

[xiv] Brändel, Markus. Dormancy and Germination of Heteromorphic Achenes of Bidens frondosa,Flora – Morphology, Distribution, Functional Ecology of Plants. Volume 199, Issue 3, 2004, pp. 228-233.

Bees & Pollinators, Birds, Books, Butterflies and Moths, Information, Insects, Native Plants, Perennials, Propagation, Seeds, Winter Sowing

Book Review – The Gardener’s Guide to Native Plants of the Southern Great Lakes Region

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by Emma Murphy, Master Gardener

Wow. What a pleasure to finally see this book in print. Written by two very knowledgeable Ontario gardeners — Rick Gray and Shaun Booth — this is the native plant gardening resource I wish I had more than 5 years ago when I started incorporating native plants in my garden.

Focused specifically on the Southern Great Lakes Region, it’s an all-in-one, easy to use resource for those interested in plants that not only look wonderful but fulfill a critical role in our gardens in supporting wildlife,  birds, and pollinators like butterflies, moths, bees, and insects.

It reminds me of an encyclopedia, with a full page spread on each native plant (and there’s over 150!). It’s not surprising to me that’s it’s already #4 on the Globe & Mail’s bestseller list.

The book is visually designed to make it easy to see key information at a glance, using quick guide key icons and two colour-coded bars providing exposure/light and moisture requirements. We’ve been blessed with several excellent native plant books in the past few years, but I appreciated several unique elements I hadn’t seen before – numerous appendices (matching soil types, seed collection and preparation, propagation, and butterflies and their host plants), as well as each plant’s Ontario’s Species at Risk status.

You’ll understand what each plant needs to thrive, how big they will get, and how to make more plants to share with your friends!

Sample spread page

As a Peterborough Master Gardener I have long been engaged in two Facebook groups – the Ontario Native Plant Gardening group (started by Shaun) and the Master Gardeners of Ontario group (where I am an admin and moderator). I remember clearly in May 2023 Rick trying to gauge interest from members on their proposed native plant book, and the incredibly positive response that they received. So full disclosure – I knew I was going to love this book before it was ever published.

The authors explain why the plants are organized by botanical/Latin name, which is important because common names can vary by region. However, if you only know the common name you can always search using the alphabetical index at the back of the book.

Essentially, each entry is a ‘checklist in a page’ on what you need to grow the plant. There are lots of photos (whole plant, leaves, flowers, fruiting bodies), a detailed description, easy to see symbols (the Quick Guide), information on the USDA Hardiness Zone, lifespan, propagation, and wildlife/pollinator value.  

Skill levels are also mentioned but don’t be alarmed – most are listed as beginner, but there are certainly a few native plants that are a bit more challenging to grow and propagate.

Table of Contents plus shameless plug for my wonderful local, independent bookstore where I ordered the book.

I appreciate that in the introductory chapters the authors clearly explain things such as:

  • What is a native plant?
  • Aggressive vs invasive
  • Origin of the term weed
  • Nativar vs cultivar
  • Value of native plants

The authors clearly have a good sense of humour – there are pages titled “How to use this book”, “A coneflower by any other name”, “Fifty shades of…shade” and my favourite “2b or not 2b” (on the rationale for using USDA Hardiness zones). I loved the section on propagation and codes as I’m actively trying to grow more native plant material in my area.

I have to say that as a seasoned gardener I was surprised to see Echinacea pallida (pale purple coneflower) is not in the book (not native to most of this region but often sold as a native apparently) and Agastache foeniculum (Anise hyssop) is one that is included specifically because it is non-native to Ontario (it’s a western prairie plant). Oops! I have both in my garden north of Peterborough.

Was anything missing? Technically no, as the authors were clear that this was not a garden design book. Perhaps after putting out Vol. 2 (the other 150+ plants I know they wanted to include), they’ll consider something on understanding planting density and creating root competition, which I am learning is different to conventional perennials, and good plant pairings (which native plants support others).

One quick comment I will add is that native plants are wonderful once they are established, so you may need to do a bit of watering that first year, but after that they need no watering or fertilizing.

If you’re interested in hearing about how this book came to be check out Rick’s Native Plant Gardener website.

This book is perfect for reading at home (my husband gave me a quick quiz contest this afternoon on the Latin names) or taking with you to your local nursery as you search for native plants to add to your garden. Having trouble finding these plants? The Halton Region Master Gardeners maintain a dynamic map listing native plant nurseries around the province. Check it out!

The bottom line – a wonderful addition to my garden library, and to anyone interested in incorporating more native plants in their Ontario gardens.

__________________________________________________________________________

The Gardener’s Guide to Native Plants of the Southern Great Lakes Region

By Rick Gray and Shaun Booth
Publisher: ‎Firefly Books, 2024
Paperback‏:‎ 352 pages ISBN-10: 0-2281-0460-2
Price: C$45.00; available through local booksellers and larger book companies

About the Authors

Rick Gray (The Native Plant Gardener) has more than 300 species of native plants in his garden in southwestern Ontario and provides native plant garden design services.

Shaun Booth runs In Our Nature, an ecological garden design business, and launched the Ontario Native Plant Gardening group on Facebook.

Want More Information?

Many wonderful books on native plant gardening and naturalization have been published in the past few years – anything by Lorraine Johnson is a great complement to this book, and I love Piet Oudolf’s work (although he doesn’t always use native plants).

Dr Linda Chalker-Scott (and the Garden Professors blog on Facebook) is a great source of good, solid scientific information on gardeners keen to avoid the misinformation often seen on social media.

And if you’re on Facebook, please follow both the Master Gardeners of Ontario and Ontario Native Plant Gardening groups.

Other Native Plant Blog Posts By Me

A Few of My Favourite Native Plants

Native Ontario Goldenrods for Your Garden

Why Do We Garden?

Ditch Lilies – A Cautionary Tale

The KISS Principle – Winter Sowing 101

Bees & Pollinators, Birds, Dreams, Garden Design, Native Plants, Perennials, Planting, Shrubs & Trees

Creating a Wildlife Friendly Hedgerow in my Ontario Garden

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by Emma Murphy, Master Gardener

Although I’ve lived in Canada for almost 50 years, I grew up in Bristol, England for some of my formative years, and always loved the traditional hedgerows that existed along rural roads and properties. Every time we return to the UK on a trip, I marvel at the diversity and intricacy of these functional garden/farm structures.

On our three quarter of an acre property in a small village north of Peterborough (Zone 4b/5a) I have a neighbour on one side who has a chain link fence and loves their golf green lawn. On the other side there is no fence at all, but I’ve been growing a few elderberries (Sambucus canadensis) and cup plants (Silphium perfoliatum) to hide a poorly maintained house – the first shrub suckers well and the second plant grows fast and tall.

So I’d love to have a traditional English-style hedgerow on both edges that would provide visual screening as well as animal and bird habitat…so I went looking to see how to adapt the traditional English hedgerow to Ontario.

Hedgerows can provide amazing bird habitat

The origins of hedgerows

It’s thought that hedgerows (or hedges) were first used by humans as ‘dead hedges’ to enclose livestock using thorny plants. Once agriculture began, clearing woodlands created fields with tree and shrub boundaries that were managed to create livestock-proof ‘living fences’.

Hedgerows have been planted since the time of the Romans and reached their peak in Britain during the Enclosure Acts of the 1700s when an estimated 200,000 miles of mostly hawthorn (Crataegus spp) hedgerows were planted.

Credit: People’s Trust for Endangered Species, UK

Hedgerows have many purposes, as you can see from this graphic from the People’s Trust for Endangered Species. They have an excellent video on how to manage a hedgerow here, but it’s not quite the same in Ontario, as we don’t have the same hedgerow species or coppicing techniques.

In their best form I think hedgerows can be a mini-ecosystem with key ingredients that animals and birds need to survive — food, shelter, nesting and denning sites. Hedgerows also function as corridors, connecting one habitat to another and offering a safe passage for wildlife. They help muffle sound, create privacy, and act as windbreaks.

Definitely not a short term project

According to the Ottawa Field Naturalists Club (OFNC), the ideal hedgerow is

  • Planted with a variety of berry- and seed-bearing shrubs for food
  • Interspersed with cedar for added cover
  • Thick, bushy, largely unpruned and entangled with vines

The Ontario Rural Skills Network suggests that hedgerows can be single species but are best if they comprise a diversity of plants. Planting should be very dense, with a double line spaced 40cm (16in) apart with plants in a staggered pattern at 30cm (12in), giving 5 plants per metre.

Because they’re comprised of living shrubs, hedgerows grow and require management. It’s all about creating a balance between growth and avoiding them becoming gapped and unmanageable. A hedgerow may take seven to 10 years to establish, depending on the species composition.

This young hedgerow bordering a field features native plants that provide habitat for beneficial insects and pollinators. Photo: Janet Donnelly, © Oregon State University

Making a plan

I’m just at the beginning of my plan for hedgerows on our property, but winter is a great time to do research. Both sites are sunny and have well drained soil, and I want to focus on using Ontario native plants as much as possible. I’m looking at a combination of seed- or nut-bearing shrubs (like speckled alder and hazel) and berry producers (serviceberry, chokecherry, red osier dogwood). Thorny shrubs (native roses, wild raspberry, hawthorns) will give added wildlife protection. The design will probably be different for each one, but that’s the fun of it.

The OFNC has excellent lists of plants you can consider for an Ontario hedgerow. I’m thinking about using

  • Speckled alder (Alnus incana)
  • Beaked hazel (Corylus cornuta)
  • Hawthorns (Crataegus spp.)
  • Common elderberry (Sambucus canadensis)
  • Flowering raspberry (Rubus odoratus)
  • Willow spp. (Salix spp.) – native if I can find them – there is an amazing group in
  • Choke cherry (Prunus virginiana)
  • Red osier dogwood (Cornus stolonifera or C. sericea)
  • Eastern white cedar (Thuja occidentalis)
  • Wild (riverbank) grape (Vitis riparia)

Next steps

I’m just at the beginning of my journey. In my next blog post on March 25th, I’ll give you an update on my research and my plans for my spring hedgerow projects. Until then, here’s some interesting sites to look at if you are thinking about something similar. And, by all means, if you have created a hedgerow in your Ontario garden, I would love to hear about it.

More resources

Creating a hedgerow for wildlife (Canada)

Hedgelink (UK)

National Hedgelaying Society (UK)

The traditional farm hedgerow (Canada)

Surrey Wildlife Trust – how to lay a hedge (UK)

1000 Islands Master Gardeners – Wildscaping with hedgerows (Canada)

How to plant a hedgerow in the home landscape (Ohio, US)

How to Start a Hedgerow (5 Steps) (Washington State, US)

A Guide to Hedgerows: Plantings That Enhance Biodiversity, Sustainability and Functionality (Oregon State U Extension)

Healthy hedgerows on your land (UK)

What have hedgerows ever done for us? how hedges benefit us (UK)