Annuals, Garden Cleanup, Perennials

Off with Their Heads

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By Christine Freeburn, Master Gardener

Deadheading is an important garden maintenance chore for July and there are several reasons for deadheading (or not). When deadheading, it is important to not just take the blossom off, but to cut the stem right back to the first junction and cut above that. Often you can just break the stem by hand, but be sure not to rip it. Use good pruning shears to make a clean cut. This applies to almost all deadheading, whether it is hosta, daylily or annuals.

The reason a plant grows and flowers is so it will go to seed and reproduce. If you remove the seed head you are encouraging the plant to put its energy back into the roots and leaves, making it become a stronger plant. Doing this as soon as possible after the flower is spent, is important for the overall look of the plant and the energy redirected.

Perennials that rebloom such as salvia, dianthus, delphiniums and roses should be deadheaded to encourage new blooms. Many new hybrids have tags that say “reblooming”, so watch for this when purchasing. Annuals like dahlias, marigolds and zinnia all benefit from cutting spent blooms to encourage new flowers.

Another reason to deadhead is to control self seeding in the garden. Many perennials and biennials will multiply by dropping seed. Forget Me Nots, Oriental Poppies, Lupins and Native Coneflowers will all appear in your garden if you don’t deadhead or disturb the soil.

Deadheading also makes the garden a bit neater. I deadhead Iris right after they bloom; cutting the stem right back. I often leave Siberian Iris to form seed pods as I use them in dried arrangements.  I don’t particularly like the washed out purple flowers on Hosta, so I usually cut them back. There are some Hosta flowers that are fragrant and white, and I like to leave those on. The profusion of flowers on the daylilies this year are stunning. I like to snap off the spent blossoms, so they don’t distract from the fresh new flowers. Peony petals separate and settle through the flower bed, so I like to remove them before this happens. Other perennials that benefit from deadheading include yarrow, cranesbill, phlox, and astilbe.

Clematis form a lovely fluffy seed head which can be left on. I also leave my Monarda didyma for the birds and the pretty seed heads.

Your hanging annual pots and containers also may need a bit of TLC by now. Annuals like to be cut back. It encourages new fresh growth and flowers, makes them bushier because when you cut a stem it will branch out. Cutting back also brings the planting back under control so it doesn’t look overgrown.

Removing seed heads is removing food that birds may enjoy. If you are growing natives, you may want to leave them for the birds, butterflies and other pollinators, however you can deadhead and leave in an open compost pile.  Although I deadhead throughout the summer, by late August, I stop and let the seed heads form on perennials like coneflower and black eyed susan so the chickadees and finches can feast.

So, get in your garden, enjoy the beautiful blooms and “off with the heads” of those that need it!

https://extension.psu.edu/to-deadhead-or-not-your-final-answer-is

Perennials, Sun Gardening, Vegetable Gardening

To Stake or Not to Stake

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By Marjorie Vendrig, Master Gardener in Training

It’s midsummer in the garden and many plants – annuals, perennials, vegetables – need to be staked and pulled upright or back. They might be flopping over to the point where stems break and buds and blossoms are lost, they might be spilling over onto other plants, blocking light and restricting growth. In the event of high wind or heavy rains, unsupported plants can easily be destroyed or can quickly become an unsightly mess.

Staking is one of those jobs that many gardeners avoid; it never seems to get done at planting time or early in the season when the plants don’t really require mechanical support. Another reason for putting off staking is that many stakes or plant supports are unsightly and look out of place, particularly very early in the season. The result is that staking is often done too late; emergency staking often looks more unsightly than a flopped over plant

Staking of some plants can be avoided: late bloomers such as sedums or asters can be maintained at a shortened height. This is done by developing shorter, bushier plants by pinching the plant by about one third in early summer. It’s a common practice for many annuals: cosmos, zinnias, nicotiana, and many other annuals are pinched back before they arrive at the nursery. (Pinching back of annuals has come to be known as the Chelsea chop, the timing for pinching back or ‘chopping’ coincides with Britain’s famous RHS Chelsea Flower Show at the end of May.)

Knowledge of the mature size of the plant, its light requirements, and any specific soil or nutrient needs could avoid the need for staking some plants. A plant with elongated, weak stems will require staking, whereas a strong-stemmed, sturdy plant that is not reaching for light or that has not been overwhelmed by neighbours is a more likely candidate to stand on its own. An honest evaluation of light levels in the garden and the sun / shade tolerance of plants are prerequisites for finding the optimal location for plants, helping to eliminate some staking.

Best advice for avoidance aside, there are still many plants that need to be staked and it’s best to match the type of support to the vigour and growth of the plant:

  • Circular grid supports with epoxy or plastic coated wire squares are best suited to clump forming perennials such as phlox, delphiniums, and some campanulas. These work best when put in place early on in the growing season with care taken to feed growing leaders through the squares. Any escapees can be tied loosely to the outside of the circle. Dahlia, peony and other top-heavy bloomers are also candidates for this approach.
  • Once blooms appear on dahlias, or other tall growers, spiral rings or Y-shaped supports are useful to prop up the blossoms. Several supports are often needed for each plant.
  • Tall, heavy blossomed dahlias and other tall growers might do better with two or even three or more stakes surrounding the plant, making sure to avoid the tuber or roots when pushing or pounding in the stakes. Bamboo, plastic coated metal, or even rebar are good choices for the supports. They should be pounded as far as possible into the grounds so that they won’t get pulled over with the weight of a wet, heavy plant. Using twine, tie a knot around one of the stakes, then a figure eight to encircle one of the stems, do the same for the other supports and stems. An alternative technique with large multi-staked plants is to tie a knot around one of the stakes, then surround the plant and loop around the next stake. As the plants grow and the blooms get heavier, several levels of twine might be necessary. Stems and plants should not be tied too tightly.
  • For shorter plants at the front of a border (penstemon, yarrow, cone flower), pea stakes are a good approach. Pea stakes are multi-stemmed off-cuts from prunings. This is an old method, historically used in vegetable gardens to support pea vines. The twigs, from birch, forsythia, viburnum, etc., are pushed into the ground around the perimeter of the plant. The plant grows up and over the stake, no tying is required, and if done early in the season, the twigs get hidden later in the season. Pea stakes are also a good way to guide climbers over to a trellis. With a bit of practice and creativity, pea stakes can be an eye-catching approach to an otherwise unappealing chore.

References

https://www.rhs.org.uk/plants/types/perennials/staking

https://hort.extension.wisc.edu/articles/pea-staking

https://www.finegardening.com/project-guides/gardening-basics/how-to-avoid-staking-plants

Advice, Fertilizer, Lawn

Managing your Lawn

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By Carol Anderson, Master Gardener in Training

Have you ever looked out at your lawn and wondered why it is not as lush and green as the neighbors? Have you tried seeding and fertilizing your lawn but are still unhappy with the results? Here are some considerations that may help you create a lawn management plan that is successful in helping you achieve what you are looking for. Keep in mind that a healthy thick lawn will reduce your lawn susceptibility to pests and disease…so keep it healthy!  And if you suspect an insect infestation such as chinch bugs (see Figure 1), web worms or grubs, you must endeavor to address this first. Similarly, a lawn with a heavy weed infestation requires special treatment, perhaps even a full lawn “renovation”, prior to a lawn management plan being initiated.

Figure 1. Chinch bug damage (https://www.ontario.ca/page/hairy-chinch-bugs-lawns)

Lawn Management Plan:

Watering: One of the most misunderstood, yet critical, elements of any lawn management plan is ensuring that your lawn receives the proper amount of water. A specific watering schedule cannot be provided given that each lawn is subject to different environmental conditions impacting its’ watering requirements. For example, the lawns facing south/west will dry out very quickly, depending upon the amount of shade. In contrast, lawns facing north/east will tend to hold moisture much longer and will require less frequent watering.  The general rule of thumb is that a lawn typically requires about 1” (30cm or 300mm) of water per week to stay healthy. If there is sufficient rainfall and overcast days, no watering may be required 😊. However, if you determine that watering is required (soil feels dry several inches below grade), the following guidelines should be followed:

1.           Sod should not be watered in the middle of the day. Sunlight on a freshly watered lawn will burn the grass blades as the water droplets act as a magnifying glass for the suns’ rays. Sod is best watered in the early morning. Watering grass at night leads to infestations with grubs and other sod loving parasites and can facilitate fungus spores to develop.

2.           It is important to water your lawn deeply and less frequently. Why? It is very important to encourage grass to grow roots that are deep in the soil. Frequent light watering encourages superficial roots to develop and eventually the creation of grass that is not drought tolerant. A good rule of thumb…a sprinkler set for 30 minutes should provide the necessary moisture to thoroughly wet the sod 4-6” below the surface.

3.           Keep in mind…once your lawn is beginning to turn brown…it is too late to start watering it!! Try to stay on top of watering and watch the weather…hopefully mother nature will help you out!

Mowing and “Grass-cycling”: Under normal conditions, an established lawn should be mowed with the blades at a height of 2½ – 3” with sharp mower blades.  For many, this feels too long. However, removing too much of the grass blade puts the lawn into a state of stress making it susceptible to disease and insect infestations.  Under normal circumstances, grass clippings can be mulched and left on the lawn (grass-cycling) as a source of additional nutrients, protection from dehydration and to attract earthworms that will naturally improve both aeration and water filtration. However, in the Spring IF the grass is heavy with moisture, and the lawn is growing quickly, you may wish to remove grass clippings.

Dethatching (deep raking): A lawn with a high percentage of fescue grass will benefit from dethatching – the removal of a thick layer of dead grass and roots that have not decomposed. This should be done if thatch is present and before aeration and topdressing the lawn.

Aeration & Topdressing and “Grass-cycling”: Grass needs nutrients and your lawn might benefit from adding a thin layer of top-dressing (compost) on the surface, particularly if the soil has a lot of clay. A lawn that has a large amount of clay will need to be top-dressed regularly with compost to provide both a steady supply of nutrients, and to improve the soil texture and water/nutrient holding capacity over time. This can be done in the spring and fall. Aerating with a core aerator, topdressing with compost and then raking will break up the cores and improve the penetration of the compost into the soil.  

Fertilization: To maintain healthy lawns, 1.5-2.0kg/100m2 of nitrogen is recommended. If using a slow-release fertilizer, it can be applied twice in the growing season (spring, late summer/early fall), with a third application of specially formulated “winter” fertilizer in late fall. Keep in mind that grass grown in the shade requires ~ 50% less nitrogen than a lawn in the sun, so it is advisable to reduce the fertilization rate by one half in the shady areas of the lawn.

Overseeding: If your lawn could benefit from thickening, overseeding should be done in the late summer/early fall when there is less competition, and the roots can take hold.

In the end, if you desire a beautiful and lush lawn, with a little bit of work and a good management plan, you can achieve this. If your lawn is suffering from a significant weed infestation, or poor soil, you may require a full “renovation” – stay tuned for my next in the series to learn about what to do!

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/
 

Bugs, Compost, Soil

Definitely Crawly but Not Creepy! The Importance of Detritivores in the Garden

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By Thom Luloff, Master Gardener in Training

Amidst the blooms and foliage in our garden lies an unsung group of heroes tirelessly working behind the scenes: detritivores.  These animals have a “creepy” reputation—we all know the surprise when we move a pot and then there is an explosive scatter of multitudes of legs!  

But aside from the free ‘thrill’, these critters play an essential role in nutrient cycling, soil health, and our overall garden productivity.

Rove Beetle and Springtail

What Are Detritivores?

Detritivores are organisms that feed on dead plant and animal matter, breaking it down into simpler substances such as nitrogen, phosphorus, and potassium, which plants can readily absorb. This recycling of nutrients ensures that the soil remains fertile and capable of supporting healthy plant growth. Invertebrates such as earthworms, beetles, and millipedes are some of the most common detritivores found in Ontario gardens.

Furthermore, the physical activity of detritivores, such as burrowing and feeding, enhances soil structure. Improved soil structure leads to better water retention and drainage, preventing issues such as soil compaction and erosion. A healthy soil ecosystem, rich in detritivores, is more resilient and productive.

Pill Bug and Millipede

Key Detritivores in Ontario Gardens

  • Earthworms (Lumbricus terrestris) are perhaps the most well-known detritivores. These segmented worms burrow through the soil, ingesting organic matter and excreting nutrient-rich castings. Their burrowing activity aerates the soil, improving its structure and allowing plant roots to access oxygen and water more easily (Edwards & Bohlen, 1996).
  • Rove Beetles (Staphylinidae family) are another group of beneficial detritivores. These beetles feed on decaying plant material and fungi, helping to break down organic matter and control populations of other pests. Their presence in the garden is an indicator of healthy soil (Newton, 2010).
  • Millipedes (Diplopoda class) are often mistaken for pests, but they play a crucial role in decomposition. These multi-legged arthropods consume decaying leaves and wood, breaking them down into smaller particles that microorganisms can further decompose (Hopkin & Read, 1992).
  • Springtails (Collembola order) are tiny, soil-dwelling insects that thrive in moist environments. They feed on fungal hyphae and decaying plant material and promote microbial growth, which is essential for nutrient cycling (Hopkin, 1997).

And my personal favourite…

  • Pill bugs, also known as woodlice or roly-polies (Armadillidiidae family), are common detritivores found in Ontario gardens. These small, segmented crustaceans are often mistaken for insects due to their similar size and terrestrial habits, but they belong to the class Malacostraca, closely related to shrimp and crabs. Yes! A terrestrial crab—how awesome is that?!  Pill bugs are easily recognizable by their ability to roll into a tight ball when threatened, a defensive behavior known as conglobation (also, an incredibly cool word!). They thrive in moist environments, often found under rocks, logs, leaf litter, flower pots, and other debris where they can avoid drying out.

Harnessing Detritivores to Make your Garden more Productive!

To encourage a thriving population of detritivores in your garden (and better soil as a result), consider the following practices:

  • Mulching: Apply organic mulch, such as leaves or compost, to garden beds. Mulch provides a habitat and food source for detritivores, promoting their activity.
  • Composting: Incorporate compost into your garden. Compost is rich in organic matter and attracts detritivores, enhancing soil fertility and structure.
  • Avoiding Pesticides: Minimize the use of chemical pesticides, which can harm detritivores.
  • Maintaining Soil Moisture: Ensure that your soil remains consistently moist, as many detritivores, such as earthworms and springtails, thrive in damp environments. 

Detritivore insects may be small, but their impact on garden health is enormous. Embracing these crawly creatures in your garden can lead to more productive and healthier plants, making your gardening experience even more rewarding.

More to learn!

To learn more about these amazing creatures, please download Bugdex wherever you get your smart device apps.  Bugdex is a revolutionary app introducing the world of insects. It is filled with stunning photographs, interactive animations and a beautiful interface designed to make entomology accessible to all. Learn how to identify major insect groups by recognizing distinctive body features that are beautifully illustrated within the guide. Bugdex is developed by a Danish-Canadian team of entomologists from the Natural History Museum of Denmark and DKB Digital Designs.

 All photos in this blog are provided with permission of Dave Cheung, Bugdex.

References:

Edwards, C. A., & Bohlen, P. J. (1996). Biology and Ecology of Earthworms. Chapman and Hall.

Hopkin, S. P. (1997). Biology of the Springtails (Insecta: Collembola). Oxford University Press.

Hopkin, S. P., & Read, H. J. (1992). The Biology of Millipedes. Oxford University Press.

Newton, A. F. (2010). “Staphylinidae Latreille, 1802.” In: Beutel, R. G., & Leschen, R. A. B. (Eds.), Handbook of Zoology: Coleoptera, Beetles. Walter de Gruyter.

Bees & Pollinators, Perennials

Let’s Talk about Baptisia!

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By Cheryl Harrison, Master Gardener

Baptisia species are part of the pea, or legume, family (Fabaceae) of plants.   The folks who develop new plants have been working on Baptisia for a few years.  The old reliable B. australis, with its pretty blue flowers, is still very available but the new hybrids feature various different flower colours.

As expected with all members of the pea family, Baptisia host rhizobia bacteria on root nodules. These bacteria are able to take nitrogen from the air and convert it to a form that is usable by the plant.  This is called nitrogen fixation.  Nitrogen is a necessary nutrient for most plants.

Baptisia prefers full sun but will grow in part shade and may reach .5-1.5 Metres (2-4 ft.) high and will die back to the ground in fall after a hard frost.  They prefer moist, well-drained soil and are drought tolerant.  All my Baptisia grow well in our zone 4-5 garden.  Baptisia spread by seeds which are pea/bean-like and form in pods.  The dry seeds rattle in the pods in the fall winds and if you brush against the plant….this makes an unusual sound in the garden.  You can prune the plant after flowering to help maintain a more rounded form but you will lose those interesting seed pods!  My plants do not flop but you may wish to add some support if needed.  The numerous, and gorgeous, flower blooms are lined up along the tall stems in late spring to early summer.  Once the flowers are done, this shrub-like herbaceous perennial will still look good in your garden with its lush green foliage and attractive seed pods.  For more information, check out this “Baptisia Plant Guide”.

Bonus….this plant is deer and rabbit resistant.  We have at least one resident rabbit and the odd deer passing through, but I have never seen any foraging damage on my Baptisia plants.  However, they are attractive to bees and butterflies.

Baptisia australis, wild/blue false indigo, are native to the eastern half of the U.S. although it has become naturalized in Ontario. The old common name wild/blue false indigo refers to the plant’s use in the southern states as a substitute for the dye indigo during the 18th century.  As mentioned, this plant has blue flowers.

Baptisia hybrid ‘Dark Chocolate’ is one that I have in my garden.  It has all of the usual Baptisia characteristics with the addition of dark brown flower blooms.  That may sound odd but they really are quite attractive.  Mine is growing beside a garden path so that a garden visitor can have a close look when strolling by.

Another Baptisia hybrid is ‘Lemon Meringue’.  This one, as you likely can guess, has yellow flowers.  It too has the typical Baptisia look.

Baptisia flowers also come in white, lavender and purple…..I hope to collect them all.  With its eye-catching presence, a Baptisia would make a great specimen plant in anyone’s garden!

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

Advice, Perennials

Please don’t eat the Daisies: Rabbit and Deer Resistant Plants

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By Christine Freeburn, Master Gardener

For many gardeners, deer are a constant problem in the garden. They can destroy a hosta display or your treasured roses in an afternoon. In my neighbourhood rabbits are plentiful and they eat many kinds of plants from tulips to hosta. I have chicken wire around the base of most of my clematis. I fence off my euonymus, willow and Rose of Sharon in the winter with fencing high enough to be well above the snow line. I have my vegetable garden fenced and try to remember to keep the gates closed. (although, this spring a determined female rabbit  learned how to jump into my fenced compost pile and then into the vegetable garden where she decided to make a nest).  I spray my tulips, roses and anything else that the critters start munching on with a product that repels deer and rabbits. It is stinky and washes off if there is heavy rain so needs to be resprayed for best results. I also use a product called Hen Manure to deter squirrels and chipmunks. Sprinkling hen manure in your freshly planted annual containers, will keep these creatures from digging. And it is an organic fertilizer too. I also cover a raised vegetable garden bed with a row cover which looks and feels like a bridal veil. It allows sun and rain in, but keeps squirrels, chipmunks and pests like beetles out and can be good for light frosts. Doesn’t look pretty but it works.

Rabbits & deer generally don’t like plants that have a fragrance. Think of mints, marigolds, sages and monardas.  Rough or fuzzy leaf textures are also characteristics that deer and rabbits don’t enjoy.

There are some lovely perennials available that fit in those categories. Check plant tags as many growers are now listing if the plant is resistant to deer and rabbits.

Below, I have listed some plants that are generally resistant.

Perennials for Sun

  • Monkshood     Aconitum carmichaelii
  • Geranium        Geranium macrorrhizum
  • Peony               Paeonia officinalis
  • False Indigo    Baptisia australis
  • Salvia               Salvis x sylvestris
  • Yarrow            Achillea millefolium
  • Lavender        Lavandula augustifolia
  • Catmint           Nepeta
  • BeeBalm         Monarda
  • Russian Sage  Perovskia atriplicifolia
  • Amsonia          Amsonia
  • Grasses – Karl Foerster, Big Bluestem, Northern Sea Oats, Blue Fescue, Blue Oat Grass

[Above, clockwise from left: Astilbe, yarrow, sage, monarda]

Perennials for Shade

  • Bleeding Heart     Dicentra eximia
  • Hellebore               Helleborus orientalis
  • Lady’s Mantle         Alchemilla mollis
  • Snakeroot               Actaea racemosa
  • Spurge                     Euphorbia polychroma
  • Astilbe                     Astilbe x arendsii
  • Japanese Spurge   Pachysandra terminalis
  • Barrenwort             Epimedium graniflorum
  • Bugloss                    Brunnera macrophylla
  • Hakone Grass         Hakonechloa macra
  • Lungwort                Pulmonaria
  • Sedge                       Carex morrowii
  • Ferns – Christmas, Cinnamon, Ostrich, Autumn, Japanese Painted

[Above, clockwise from left: Rabbit, geranium, Japanese painted fern, bleeding heart]

There are some shrubs that deer and rabbits usually don’t bother with. They include Weigela (Weigela florida), Spirea (Spiraea japonica) and Potentilla (Potentilla fruticosa).

Bulbs like Daffodils (Narcissus), Snowdrop (Galanthus nivalis),  Ornamental Onion (Allium) and Autumn Crocus (Colchicum) are not favourites for deer.

Annuals like Dusty Miller (Senecio cineraria),  Licorice (Helichrysum petiolare), Caster Bean (Ricinus communis) and Marigold (Tagetes tenuifolia) have rough or fuzzy leaves or a strong smell that deer or rabbits don’t like.

Herbs like Oregano, Rosemary, Thyme, Sage & Basil have a fragrance creatures stay away from also.

The plants listed above are generally resistant, but are not guaranteed to be deer and rabbit proof. If food is scarce or the creature is adventurous, they will try anything. Sometimes, rabbits just nip the flowers and leave them (grrrrr!)

Having wildlife in the garden is lovely and we enjoy watching our rabbits. But it is nice to have enough of the right plants that will survive and give a nice display of flowers. Balance in nature.

Advice, Drought, Sun Gardening, Waterwise

Preparing your garden NOW for the summer heat

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By Mary-Jane Pilgrim, Master Gardener

As the summer heat ramps up in Ontario, it’s time to get your garden ready to thrive in the hotter summer months. Here are some essential tips to ensure your garden stays healthy and vibrant despite the scorching temperatures that are most likely to hit us by the end of the month.

First, make sure to water your perennial plants deeply but less frequently now to get them used to what’s ahead. Early morning is the best time to water as it allows the moisture to penetrate the soil before the sun evaporates it. Consider investing in a drip or spray irrigation system to deliver water directly to the roots or lower portions of the plants, minimizing water loss through evaporation. Collect water in rain barrels for hand watering.

Newly planted trees, natives and other plants will begin to need extra support to make it through our harsh summer, and it is often a time that gardeners also struggle. Gardening seems so much easier in the spring, when everything is new and fresh, but do not give up when the temperature climbs and climbs! Summer gardening is so important to having a good garden year-round and working outside in the summer has its rewards too.

Native and non-native plants that have been planted this spring are probably not well enough established to be on their own this first summer, so they will need supplemental water this summer. For this purpose, I’ve purchased a couple dozen “pop bottle watering spikes” that screw onto a 2L pop bottle. Cut the bottom off of the bottle, put the spike on the threaded end and invert into the soil. The spike delivers water at a drip pace — I place these bottle waterers at the base of every new addition each year. By next summer, they can usually handle the dry conditions in our area a little better.

Version 1.0.0

Newly planted trees and shrubs get the “holey pail” treatment. Source a small pail like the ones that kitty litter comes in, and drill about 5 holes in the base. Place a pail beside each new tree or shrub. When temperatures soar and rain is scarce, drop a couple of litres of water into the pail. It will trickle out into the soil around the tree at a slow speed that will allow the tree to utilize the water.

Mulching is another crucial step in preparing your garden for the summer heat. Apply a layer of organic mulch on your flower beds and possibly a cheaper alternative such as straw or wood chips around your veggie beds to help retain moisture in the soil, regulate soil temperature, and suppress weed growth.

Don’t forget your trees! Apply 2 to 3 inches (5-7cm) of mulch around your trees, keeping it at least a few inches away from the trunk, avoiding mulch that has been artificially dyed.

Lastly, keep an eye out for pests and diseases, which tend to thrive in warm, humid conditions. Regularly inspect your plants for any signs of trouble and take appropriate measures to prevent infestations.

By following these simple tips, you can ensure your garden stays as lush and thriving as possible throughout the hot summer months which are just around the corner!

Hedging, Shrubs & Trees

Planting Cedars in the Ontario Landscape

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By Emma Murphy, Master Gardener

I see this question every year on our Master Gardeners of Ontario Facebook group – someone goes to their local big box store in the spring, purchases emerald cedars (usually Thuja occidentalis ‘Smaragd’ or ‘Brandon’) to create an instant hedge and within 6 months to a year they are browning and dying and people ask what they are doing wrong.

What’s the Issue?

Both these cedars are native to North America. So-called “Emerald Cedars” are usually Thuja Occidentalis ‘Smaragd’.

FUN FACT – Smaragd is the Danish word for “emerald”.

According to some British Columbia (BC) growers Thuja Occidentalis ‘Brandon’ supposedly grows slightly faster and is bushier and hardier.

Both grow in a columnar shape. This spring I also saw Thuja occidentalis ‘Skybound’ in my local big box store, which is apparently hardier than the ‘Brandon’ cultivar.

In general I don’t recommend any of them for Ontario gardens, and this is why.

Emerald cedars arrive by the truckload each spring from BC growers, where they are grown in cooler summer temperatures with abundant rainfall (compared to Ontario).

Ontario’s summer heat and increasing drought conditions simply cannot support these shrubs; Ontario winters are also a challenge because of frigid temperatures and drying winds causing desiccation or moisture loss of needles. Ontario’s more humid conditions also result in fungal diseases affecting the shrubs.

Photo credit: Pacific West Cedars, BC

Generally seen at big box stores, they are often poorly transported across the country with no water, completely root bound, and poorly-maintained at the stores, and stressed cedar (hey you’ve moved it to a hot Ontario summer from where it was born) often means they die over the summer or in winter even if you care for it.

Bigger is Not Better, and Other Problems

Also, bigger is not better, as they often don’t survive transplanting, and you see a lot of dead or dying brown emerald cedars. If you really want a large emerald cedar (6-7 feet) you should be paying good money from a reliable year-round nursery, not a big box store. I speak from experience as I tried to create a hedge at my previous house in Kitchener.

If you do insist on planting them they must be in full sun. Make sure they get plenty of water in their first year of growth, right up to when the snow flies. A thick layer of mulch will help them to retain that moisture as well. Come winter time, protect them with a layer of burlap to protect them from heavy blankets of snow, which can bend or snap delicate branches.

What’s the Alternative?

For me that’s way too much work. If you are looking to create a visual barrier or hedge I would recommend planting Ontario-grown white cedars (also Thuja occidentalis). It is inexpensive and often dug from ‘native plantations’ that are bare root seedlings.

Finding Ontario Eastern white cedar means that the tree was grown in Ontario which ensures a good adaptation to our climate. They grow well in all soils – from clay to sandy, in full sun to part shade. After planting, trees need regular watering, particularly during dry periods, for the first few years. Once established white cedars are low maintenance and very resistant to issues.

There’s no instant hedge here – they take a few years to settle in but once they have you can expect up to a metre of new growth each year (in the third year). Plant ones that are a metre high or less to start – in this case bigger doesn’t mean better as they will take longer to settle in. There are quite a few companies that will also come and actually trench and put in the cedar for you, or just sell you the plants. Just Google “Ontario white cedar” and several companies will show up.

Or…you can look for other hedging choices like Skyrocket Juniper (Juniperis scopulorum ‘Skyrocket’) or if you have shadier conditions – Japanese Yew (Taxus cuspidata ‘Capitata’) or Hick’s Yew (Taxus x media ‘Hicksii’). I’m excited that the Canada Yew (Taxus canadensis) is finally also being propagated in Ontario and will be a choice in the future.

Another Option – Creating a Native Hedgerow

I’ve been looking at a hedge to provide some shielding from my neighbour’s property so I explored the idea of a native hedgerow in a Master Gardener blog in January this year. Here’s one of the good resources that I was looking at from the Ottawa Field Naturalists’ Club.

Credit: People’s Trust for Endangered Species, UK

They suggest 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

Whatever you choose to do, there are many options that are better than “emerald cedars”.