Category Archives: Propagation

Advice, Bees & Pollinators, Birds, Books, Communication, Dreams, Fruits, Greenhouses, Health, Herbs, Houseplants, Information, Native Plants, Overwintering, Perennials, Propagation, Vegetable Gardening, Wildflowers

Time for Reading Garden Books

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by Christine Freeburn, Master Gardener

In this day and age, we spend so much time on our computers, googling all the information we want and need. But there is something about sitting by a sunny window on a cold winter’s day with a good book.

The winter months are a great time to pull out an old gardening book or invest in a new one. The days are now getting longer and spring is coming, but actual gardening is a few months away. Time to learn something new to help you improve your gardening skills. There are many good Canadian and zone appropriate books that can help you.

Below, I have listed a few of my favourite books on my bookshelf. I have also asked my fellow Master Gardeners to share their favourites. Some of the books are out of print, but check your local library, used book stores or online sites. Enjoy!

For the Houseplant Gardener

The New Plant Parent

Darryl Cheng gives advice that is full of common sense. He explains that leaves do die and plant care should be enjoyable, not a chore. He discusses basic requirements for healthy plants including the right light, soil care and proper watering. Great illustrations and nineteen plant varieties are listed in detail. Look for his newer books also.

For the Vegetable Gardener

Plant Partners

Companion planting has been around for years. Jessica Walliser gives us “science-based companion planting strategies” that help with disease and pests, improves soil and supports pollinators. Lovely illustrations throughout will have you dreaming of your next vegetable garden.

Growing Under Cover

Niki Jabbour is the Canadian half of the popular website Savvy Gardening (along with Jessica Walliser). She has several books out, but this one gives great information about how to reduce pests with row covers. Niki has several books out, so check them out.

The Kitchen Garden

Peterborough MG Silvia Strobl first toured Patrick Lima and John Scanlan’s garden on the Bruce Peninsula over 40 years ago and was inspired by both their colourful perennial and productive vegetable gardens. Each spring, she still refers to this book’s excellent information to refresh her memory on time to sow, spacing, thinning, harvesting, etc. for the vegetable crops she grows! Unfortunately, this book is out of print, but you may find a used copy online.

Incredible Edibles

This book by Sonia Day is recommended by Peterborough MG Deb Fraser. It is very basic for the beginner gardener. It answers when, where, how, as well as other questions for herbs and vegetables. She even gives a recipe for each plant. Another book that is out of print. Try used book sites.

Encyclopedia of Herbs, Spices & Flavorings

Deb also suggests the Encyclopedia of Herbs, Spices & Flavorings, a cook’s compendium by Elisabeth Lambert Ortiz. Originally British but published in Canada by Readers Digest, 1992. It is beautifully illustrated and very detailed about the origin of herbs, spices, oils, sauces, coffees and teas around the world. She details the origin of these, how to cook with them and a recipe. When the weather is frightful with a nice warm drink in hand it makes for interesting reading, perhaps planning to add a few herbs to your garden next spring.

For the Perennial Gardener

The Well-Tended Perennial Garden

Peterborough MG Gladys Fowler’s favourite book is the Well Tended Perennial Garden. Tracy DiSabato-Aust’s book has an extensive encyclopedia of perennial species and cultivars and she explains the maintenance and pruning needs of each plant. The explanations and illustrations are excellent.

For the Native Plant Enthusiast

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

For Peterborough MG Emma Murphy, definitely this one on native plant gardening – for our region, gives everything you need to know about growing the plant, including propagation, wildlife value and what butterflies and moths it is a larva host for. For a full book review she did on Rick Gray and Shaun Booth’s book when it was published in 2024 click here.

A Garden for the Rusty-Patched Bumblebee

Peterborough MG Sharleen Pratt says this book by Lorraine Johnson and Sheila Colla not only goes into great detail about Ontario native plants, vines, shrubs and trees, but it also encourages us all to think about the spaces we create so that pollinators can thrive.

For the Environmentalist

Our Green Heart

Peterborough MG Carol Ireland says it feels good to sit down and read something that requires absolute attention while at the same time causes you to make all the connections between what you are reading and the place trees have in the survival of our planet. This one by Diana Beresford-Kroeger is also on my reading list!

What is your favourite gardening book? What do you have on your list to find and read next? Eleven more weeks till spring!

Check out previous reviews on our website

Favourites From My Bookshelf

Four Great Books

Advice, Houseplants, Propagation

The Price of Growth: How Plant Propagation Shapes Plant Prices

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By Brandi McNeely, Master Gardener in Training

While shopping for plants at my local big box store recently, I came across a beautiful Monstera Thai Constellation at a reasonable price. If you’re a plant collector like me, you might think, that’s awesome! If you’re not, you might ask, what’s a Thai Constellation, and what’s the big deal?

Serious plant collectors can tell you what’s trending in the market and the crazy prices these plants sell for. Thai constellations are a natural sport of standard Monsteras, with showy variegated leaves (whereas the standard plant is solid green).

In the last few years, specimens have been selling for hundreds of dollars in specialty shops – but now they are readily available in large quantities at relatively low prices in big box stores. Why the change? To understand this, you need to understand propagation techniques.

Seed Starting

When you purchase your annual flowering plants in the spring, chances are they were started from seed at the nursery. Many plants (marigolds, zinnias, and celosia) are easy to start from seed and grow quickly, making seed starting a cost effective method of propagation for nurseries. So easy in fact, that many people start their own at home using this same method.

Division

Some plants are propagated using division. Think of your garden in the Spring when hostas begin popping up. You can use a spade to cut the plant in two, instantly doubling your plants. Some tropical plants are propagated using this method, including snake plants and calathea.

Grafting

Grafting is the horticultural technique of joining two different plants to grow together as one. When you purchase a Honeycrisp apple tree from a garden center, the tree is a Honeycrisp stem (scion) grafted onto the rootstock of another apple variety. Honeycrisp won’t grow true to seed and must be grafted in order to produce true fruit.

Cuttings

Have you ever cut a stem from a house plant and rooted it in water on a windowsill? Nurseries use this technique on a much larger scale. Using stem cuttings and growing medium, nurseries can produce large quantities of plants for sale (although this does require time to allow the cuttings to grow into small plants). Pothos are a great example of plants that are easily propagated through stem cuttings.

Tissue Culture

This brings us back to the Thai Constellation. Monsteras are easily
propagated through stem cuttings, but growing one variegated offshoot
for stem cuttings takes time. Tissue culture is a relatively new practice in the houseplant industry, where plant tissue is grown in a nutrient rich medium to produce a large volume of plants in a laboratory setting. These plants are a clone of the mother plant, ensuring consistent characteristics within large scale production. Tissue culture can produce plants on a large scale fairly quickly, driving down the cost of new, rare variations.

One plant can take years to grow into a small, steady supply of plants. Low supply and high demand results in high prices for buyers.

With advancements in propagation methods like tissue culture, the once-exclusive world of rare plants is becoming more accessible to everyday plant lovers. What was once only available to collectors willing to pay top dollar can now be found in the garden section of your local store.

Understanding how propagation influences both supply and cost helps explain market trends and reminds us that behind every “rare” plant, there’s often a bit of science making it possible for more people to enjoy its beauty.

Annuals, Planting, Propagation, Seeds, Winter Sowing

Don’t Let Facts Keep You From Gardening – An Observation

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by Marilyn Homewood, Master Gardener

Master Gardeners (MGs) in the Province of Ontario are experienced gardeners who have studied horticulture extensively and who continue to upgrade their skills through technical training. With this training MG’s are able provide quality horticultural advice to the general public via garden clinics, telephone, letters, displays, workshops, television, radio, the web and newspaper articles. This provides the public with advice based on science.

BUT… “Book Learning” (as the older farmers in my neighbourhood refer to it) doesn’t always tell the whole story. There are many instances where the “right” answer is not always the best or the only answer. For example, Dr. Keith Hammett, a famous sweet pea breeder and researcher maintains that sweet pea seeds do not require soaking in order to aid in germination.

However, at my house any of the unsoaked sweet peas seeds never germinate while the soaked seeds of the same varieties do. Same seeds, same potting mix, same growing conditions. What’s up??? In order to ensure I have plants; I simply soak my seeds.

For the past couple of years I have been trying (unsuccessfully) to grow breadseed poppies. Conventional wisdom states that these seeds are best direct seeded outside in early spring as poppies do not tolerate root disturbance and transplanting. But when I direct seed nothing comes of it.

This past winter, I decided to ignore conventional wisdom and to conduct my own trial at home. I sowed the same type of bread seed poppies three different ways: Winter sowing, in trays indoors that would later be transplanted and direct sown into the ground.

The winter sown seeds were not as plentiful as I thought they may be but some germinated which I transplanted in the bed. I suspect that a heavy rain had washed the seed to the side of the shed the seed to the sides of the container where only a few germinated.

Winter sown seedlings at container’s edge

The direct sown seeds for the most part did not germinate and the few that developed did so late in the year. However, the indoor raised seeds did well. So much so that I always seemed to be thinning them.

Being mindful of their sensitive roots I sowed a number of seeds into larger cells. Plants were thinned not by pulling which might disturb the remaining roots but by cutting off at the soil surface with scissors. When it came time to transplant outside, the entire cell was lifted and transplanted into the soil.

Seedlings started indoors in large cells.
Seedlings transplanted to garden. Tiny seedlings are from direct sowing.

I had direct sown 4 lines of seed in the area that I transplanted the winter sown and indoor started plants. As time passed the indoor started seedlings overtook the others and produced the best and the most plants. The other methods did work but not well and the method cautioned against was the most successful. I suspect that I mitigated the problems of root disturbance by using an overly large cell to start them in and handle them as a unit.

Mature Sissinghurst White Breadseed Poppies.
Seed pod on Bowling Ball Poppy.

It isn’t that the conventional recommendation is wrong, it is wrong for my situation (I often do not have enough consistent moisture in order for direct seeding to be successful).

Here’s how I look at it. The facts are the guidelines we use to get started and our experience can fill in rest. Never stop experimenting with new methods. After all, someone had to be the first to try winter sowing or no till gardening.

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

Advice, Annuals, Propagation, Seeds

‘Garden Jeopardy’ Seed Starting Edition

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by Lois Scott, Master Gardener

I don’t know about you but when I am listening to people talk about specialized topics it can seem like they are speaking a different language. 

Gardeners and gardening can be like that! 
So welcome to the first edition of Garden Jeopardy.

Image by pch.vector on Freepik

You can learn about or review a few terms and definitions and then “dazzle” your friends and family with your seed starting knowledge and vocabulary!

The process by which a plant grows from a seed into a seedling. 
What is germination?

Optimal water, oxygen and proper temperature. 
What are the conditions a seed needs for germination?

The absorption of water by a seed.  
What is imbibition?

The part of a seed which acts as a food source for the developing plant embryo. 
What is the endosperm?

The first leaf or one of the first pair of leaves developed by the embryo of a seed. 
What is a cotyledon?

The part of a plant embryo that develops into the primary root.  
What is a radicle?

The process by which plants use sunlight, water and carbon dioxide to create oxygen and energy in the form of sugar. 
What is photosynthesis?

A sterile, lightweight, free from weed seed product that is usually composed of vermiculite and peat or coir with no true soil in it. 
What is a soil-less seed starting mixture?

The process in which seedlings/plants grow leggy (long), pale and yellowed due to insufficient light. 
What is etiolation?

A disease of young seedlings caused by certain fungi and water mold that thrive in cool, wet conditions.  Providing constant warmth under seedlings can help prevent this. 
What is damping off? 
Learn how to prevent damping off!

The process of allowing a plant to transition from a protected indoor area to the harsh outdoor conditions of fluctuating temperatures, wind and full sun. 
What is hardening off?
Learn how to harden off!

Moving a plant into the garden so it can continue to grow. 
What is transplanting or planting out?

Thanks for playing!

Cotyledons
Photo: Gavin Scott

Perennials, Propagation

Love Me Tender

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by Lois Scott, Master Gardener

At this time of year that nasty five letter word “frost” starts making an appearance in the weather forecast.  Our hardy perennials will manage just fine with freezing temperatures but some of your plants may be tender perennials that won’t survive winter.  As a reminder, a perennial is a plant that will live for more than two years.  This can include bulbs like begonias and dahlias, rosemary, and geraniums just to name a few.  Annuals complete their life cycle in one year and biennials in two.  Tender perennials can give us years of beauty if we treat them well. 

Pelargoniums, commonly called geraniums (which are different from hardy Geraniums/Cranesbill) are a tender perennial in our climate but they are easily wintered over using one or all of three different methods.  You can take a stem cutting, overwinter as a potted plant, or overwinter as a bare-root plant. This link gives clear instructions for all three methods. 

Personally, I will be taking a stem cutting from a geranium and a Dorotheanthus bellidiformis ‘Mesbicla’, commonly known as Mezoo Trailing Red, another tender perennial.  Cuttings produce a plant identical to the parent, avoids any difficulty with starting from seed and will frequently produce a plant that matures faster and flowers sooner than a plant grown from seed. 

I will be using an 8-10 cm stem that includes a few leaves.  Make sure your cutting contains as much water as possible by watering your plant the day before and taking your cutting before the heat of the day reduces water content.  Plants lose most of their moisture through leaves so I will remove half to a third of the leaves. Ideally, process the cutting right away or place it in water. 

Using clean pots and tools, and soilless potting mix or vermiculite is important to reduce the chance of disease killing your cuttings.  Once your pot is ready, secure the cutting by placing it into the medium far enough that the cutting can support itself.  Put your pot in a closed plastic bag and place it in a warm, bright spot but not in direct sun.  The plastic bag should keep the plant’s environment humid enough to prevent water loss in the cutting and reduce the need for any further watering.  Too much moisture and the cutting will rot.  More info here.

In a few weeks you should be rewarded with good root growth on your cutting which you can then repot and grow on for use in the garden next year. 

Advice, Information, Propagation

Using Root Cuttings to Propagate Plants

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by Marilyn Homewood, Master Gardener

Most of us are familiar with using stem cuttings to make a replica of a specific plant. Less commonly used in Canada are root cuttings, a form of asexual reproduction which can be used to propagate a range of herbaceous perennials and even a few woody plants in the later part of autumn when plants have gone dormant (full plant listing in references).

Beauty of Livermere Oriental Poppies (parents)

Last fall, I determined that I would need approximately 25 new oriental poppy (Papaver orientale) plants to place at the back border of one of my beds. “Beauty of Livermere” was already planted in another bed and I wished to have more of that variety. However, poppies have tap roots and are notoriously difficult divide. As oriental poppies do not come true from seed when looking to reproduce a particular cultivar, root cuttings seemed to be the answer.

As I had never done this before, I choose to take cuttings at more than one time – late September, late October and in the end of December when we had a surprising warm spell. I lifted a couple of plants brushing away the soil from the roots (washing would have worked better). I selected out roots with a diameter of a pencil and cut them off with secateurs taking less than 1/3 of any one plant. The donor was replanted immediately (and the crown mulched for winter protection).

Next, the roots were cut into 2–4-inch (5-10 cm) lengths making a horizontal cut at the upper end (part that was closest to the plant crown) and an angled cut at the bottom. You must preserve the polarity of the cutting. They will not grow if planted upside down. I filled pots with a 50/50 mixture of potting soil and vermiculite (perlite also works). I inserted the cuttings vertically into compost, ensuring that the angled end of the cutting was put in first to preserve polarity. The compost was watered until it was moist and then put out in my extension for the winter where they would be cool but would not freeze. Root cuttings do not require light until green growth begins to show and they can be kept in the basement if need be.

2 months (left) and 3 months (right)

In my case, it took about 2 months before any of the cuttings showed any green. The September cuttings were a flop as only a single cutting out of 10 had growth (too early to take root cuttings). I had almost 100 % strike from both the October and December batch. The cuttings were in a high light area so as they grew on, I did repot them up. In late April, the new plants were hardened off and planted out. They grew well in their new location and I look forward to next year’s bloom.

Potted up separately
Planted out!!

There are other advantages to using root cuttings instead of other means of propagation:

  • Root cuttings require no special aftercare (no humidity bag etc)
  • Large numbers of new plants can be generated from a single parent plant (good for larger gardens)
  • Plants derived from root cuttings are relatively large and vigorous
  • Cuttings are taken in a quieter season when a gardener may have a bit of time (I don’t know about you, but my spring stem cuttings have a high failure rate as I don’t keep as close an eye on them as I should and they either burn up in the plastic humidity bag or dry out from lack of water)
Growing on…

Perennials such as Japanese anemones (Anemone hupehensis) and Phlox (Phlox paniculata) can be propagated in this way. These plants have thinner roots and contain less food reserves so it is recommended for these species to use longer sections (3-5 inches) and lay them horizontally on top of compost in a tray covering with a thin layer of compost.

Whatever plant you wish to propagate, give root cuttings a try. You may be pleasantly surprised.

Resources

Propagation by Root Cuttings (RHS)
Plant Propagation
Grow More Plants with Root Cuttings

Advice, Perennials, Propagation

Peonies: The Stars of the Show at Present

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By Mary-Jane Pilgrim, Master Gardener

Peonies are like the royalty of the flower world, with their lush petals and captivating fragrances. If you’re itching to grow more of these stunning beauties in your garden, you’re in luck!

Peony plants fall into one of three categories: herbaceous peonies, tree peonies, and intersectional/Itoh peonies (modern crosses between herbaceous and tree types). This article addresses the propagation of herbaceous peonies by seed and by division.

  1. Growing Peonies from Seeds: Starting peonies from seeds is like embarking on a rather long gardening adventure. First, collect ripe seeds from mature peony plants once the flower heads have dried. Give them a good soak in water for a day to help with germination. Then, plant the seeds in well-draining soil in a pot or tray. Cover the container with plastic wrap to create a cozy greenhouse effect.

Now, it’s time for a little winter simulation. Pop the container in a cool spot like your fridge for about three months. After the chill period, move the container to a warmer spot with indirect sunlight. Keep the soil moist, and be patient. It might take a while, but soon you’ll see those precious seedlings sprouting. Once they grow bigger, you can transplant them into individual pots or your garden. Remember, it may take a couple of years for them to bloom.

  1. Dividing Peonies: Dividing peonies is like giving them a fresh start and making more peony magic happen. Autumn or early spring is the perfect time to divide these beauties. Carefully dig up a mature peony plant, making sure to keep as many roots intact as possible. Gently shake off excess soil and look for natural divisions or “eyes” on the plant – these are the points where new shoots will emerge.

Grab a clean and sharp knife, and cut the plant into sections, making sure each division has a few healthy roots and eyes. Then, replant these divisions in well-prepared soil in a sunny spot. Give them a good drink of water and watch as they settle in and grow. Don’t be surprised if it takes a year or two for the divided peonies to bloom, but when they do, it’ll be worth the wait!

With these two propagation methods, you can expand your peony collection and enjoy a blooming paradise in your garden. Whether you choose seeds or division, the joy of growing peonies will reward you with breathtaking blossoms and a sense of accomplishment. Happy gardening!

Bees & Pollinators, Perennials, Propagation

Why are my Columbines Changing Colour?

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by Emma Murphy, Master Gardener

Columbines (Aquilegia spp) are lovely perennials. I have had them in my garden for many years, and they always offer a pop of colour in the late spring/early summer garden here in Lakefield, Ontario.

These easy care perennials come in a variety of colours, shapes and sizes – most are bi-coloured, ranging from pastel shades to vibrant hues. Columbines have distinctive five-petaled flowers with long backward-extending spurs as pouchlike extensions of the petals, containing nectar. Sepals and petals are brightly coloured. The leaflets of the compound leaves are usually rounded and notched.

In my garden I have both cultivars and straight species (native) columbines, but it was a query on our Master Gardener of Ontario’s Facebook page about someone’s columbines changing colour from year to year that caused me to go down the research rabbit hole to try and find an answer for them.

What Did I Find Out?

Well, apparently columbines really like to hybridize with other columbines. They really do. They are also sensitive to their soil conditions and a number of other factors.

There has been some fascinating research done at universities like UC Santa Barbara (here and here). In one study they used two columbine varieties – red columbines pollinated by hummingbirds, and white or yellow columbines pollinated by hawk moths. Apparently hummingbirds prefer medium length nectar spurs (the ‘tails’ on the columbines), while hawk moths prefer the relatively longer-spurred species.

A. formosa (left) is primarily pollinated by hummingbirds. A. pubescens (right) is primarily pollinated by hawk moths.
Source: https://people.eemb.ucsb.edu/ballerini/evangeline/research.html

The study also noted that columbines can change from blue to red, then white to yellow. According to the researchers, the colour shift from red to white or yellow in columbines has already happened at least five times in North America.

So Why Do They Change?

There are several reasons why columbines change colours:

  • DNA mutation
  • Natural selection
  • Adaptive radiation
  • Hybridization
  • Changes in soil conditions

DNA Mutation

Based on the UC Santa Barbara findings, at least 34 genes produce different columbine flower colours. Because of the presence of various genes, there’s an increased likelihood that the colours will change simply due to gene mutation. It doesn’t happen because of creation of new genes, but just because of current gene mutation.

Natural Selection

In the studies and mentioned above, if most pollinators are hummingbirds, most of the columbine colours are red. However, when the population shifts and most of the pollinators become hawkmoths, there’s a potential for the colour to modify. The resulting blooms can be white or yellow.

Adaptive Mutation

Another concept explored in the study of the columbine colour changes is adaptive radiation, based on Charles Darwin’s Theory of Evolution, which assumes that living organisms change their structures to better adapt to the changes in their surroundings. For columbines, flowers develop new traits as a response to changes in their environment. In this case, the changes include the pollinators. 

Research shows that columbine flowers are tailored to the tongues of their pollinators, which shows an example of how they evolve based on their environment.

Hybridization

Columbine colour change can also be due to cross-breeding, when male and female parts are pollinated. The goal? Combining the positive attributes of two species, changing the physical characteristics, resulting in a better yield and disease resistance, among others. 

Hybridization can also occur non-deliberately – for example when we plant two columbine varieties near each other, this will often create colour changes from the original plants.

To prevent problem hybridization, especially with our native Eastern Red columbine (Aquilegia canadensis), the best thing you can do is plant the native species as far away from the cultivars as you – not foolproof but an important thing to consider. Or don’t have any cultivars on your property, but that doesn’t guarantee they will stay the same as pollinators move from garden to garden.

Changes in Soil Conditions

It’s common for columbine colours to shift because of slight changes in the soil’s pH, as well as the presence or absence of metal ions in the soil. A pH lower or higher than 6.0 to 6.5 can result in nutrients being unavailable, which in turn can affect colour.

Our beautiful native Eastern Red Columbine (Aquilegia canadensis)

Colour change in columbines is a fascinating phenomenon, as you can see from my “rabbit hole research”.

But here’s the bottom line – if you want to keep your native columbines from hybridizing with cultivars you have to keep them as far away from each other as possible. If you like the idea of them changing colours (for a variety of reasons) just sit back and enjoy!

MORE READING

Sudden evolutionary change in flowers (2022)

Biologists discover a gene critical to the development of columbines’ iconic spurs (2020)

‘A Hopeful Monster’ (2022)

Dramatic diversity of columbine flowers explained by a simple change in cell shape (2011)

Bees & Pollinators, Garden Design, Garden rejuvenation, Native Plants, Perennials, Planting, Propagation

The Golden Glow Has Got To Go

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By Emma Murphy, Master Gardener

Last year around this time I wrote a blog about reclaiming a garden bed from the dreaded ditch lily (Hemerocallis fulva), now considered an invasive species by many organizations including Ontario Parks and the US Fish & Wildlife Service and the U. S. National Park Service. If you’ve ever struggled with this plant you know what I mean.

The other plant growing in our large Lakefield garden when we moved in (more than 20 years ago) is what I was told was called an ‘outhouse plant‘. I eventually learned that the Latin name for this plant (also called golden glow or tall coneflower) was Rudbeckia laciniata “Hortensia”.

Rudbeckia laciniata “Hortensia” or Outhouse Plant, circa 2005 in my garden

It’s a cultivar of our native Rudbeckia laciniata, also known as Cut Leaf Coneflower or Green Headed Coneflower, which has a lovely simple daisylike flower (whereas the Hortesia cultivar is a double ‘puffy’ flower).

Our lovely R. laciniata elsewhere in the garden. It will do better (and flop less) if it’s in a garden bed with other tall and native plants.
Native R. laciniata flower to the left and R. Hortensia (double flower) to the right

The outhouse plant was pleasant enough so I let them grow for years in what I call our ‘back 40’, meaning our naturalized garden area at the back of the property, behind the cedar rail fence. Yes they were tall and gangly, and fell over in thunderstorms. Yes they spread, but they gave the prolific Canada Goldenrod (Solidago canadensis) and New England Asters (Symphyotrichum novae-angliae) a run for their money in August/September. And hey, I had more than enough to deal with in the rest of my more organized garden!

However, as I started to learn more about both native (and invasive) plants over the years I realized that I might have a problem. The outhouse plant isn’t a huge problem per se, as it can be controlled through digging, Chelsea chop etc., but its double shape means that it offers minimal benefit as food for our pollinators. And I wanted plants that not only look beautiful but have an ecological benefit. So I sat in my hammock and pondered.

Sitting in my hammock contemplating the outhouse plant’s fate
(he’s watching on the right)

As a result of winter sowing (first time this past winter – highly recommend!) I have lots of new native plant seedlings, including some of the ones I featured in my May blog – A Few of My Favourite Native Plants – Culver’s Root (Veronicastrum Virginicum), Cardinal Flower (Lobelia cardinalis), and Green Headed Coneflower (Rudbeckia laciniata). I certainly have lots of the native Rudbeckia, as well as Boneset (Eupatorium perfoliatum), Giant Ironweed (Vernonia gigantea), and Purple Giant Hyssop (Agastache scrophulariifolia).

So the clearing of the outhouse plant began in earnest last week, and by the end of two afternoons I had an area to work with.

The initial chop of material
Then removal of the actual plants and roots

Definitely not light work, but not too difficult either compared to other plants. The area is now clear, and I’ll be putting in Green Headed Coneflower (the native), Boneset, Giant Ironweed, and Purple Giant Hyssop. They can all tolerate a little competition (a good thing for native plants, especially tall ones) and basic soils.

If I have space I might even mix in some shorter plants like native Bush honeysuckle (Diervilla lonicera) and Pearly Everlasting (Anaphalis margaritacea) in at the front as they can tolerate dry conditions. The area is mostly sunny all day. Unfortunately my beloved Cardinal Flower and Turtlehead are too dry for this location.

We’ll see how this experiment works and check back in with you all on another blog. If it works we’ll expand into another area of outhouse plant that I recently cut down, but haven’t removed yet…a work in progress. There are only so many hours in my (still working part time) day. And I still need to get that Canada Ggoldenrod under control…but that’s another story…

The next phase of the project.