We all love lists. As we click on a promising headline, we anticipate an easily digested scrap of knowledge – not too much information, not burdened with complexity, but knowledge nevertheless - simplified, ordered, finite, authoritative. Armed with a list, the gardener can face up with a measure of confidence to the bewildering array of choices in the seed catalogue or garden centre.
But watch out - not all lists are created equal. In fact, a study published in the journal BioScience in 2014 looked at lists of pollinator-friendly plants in the U.K., Canada and the U.S. and found surprising shortcomings and misinformation, both in the lists, and in plant labels that rely on them. One list, compiled by a government-funded organization called Natural England, was described as looking “very much as if it was put together late one Friday afternoon.”
A list is only as good as the data that has gone into it, the study authors point out, but surprisingly they found the empirical sources on which lists are based are almost never provided. The study found that many good pollinator plants were omitted while poor plants were sometimes recommended. Here’s the link: ‘Listmania: The Strengths and Weaknesses of Lists of Garden Plants to Help Pollinators’
by Mihail Garbuzov and Francis L. W. Ratnieks.
One factor that I feel the authors could have mentioned relates to the distinction between a food plant and a host plant. These pollinator plant lists all appeared to be lists of food plants. Most pollinating insects collect nectar and pollen from a wide variety of flowers. But when it comes to creating the next generation, butterflies and moths are often limited in the number of plant species their caterpillars can consume (think Monarchs, that can only reproduce on Milkweeds). Insects that go through a caterpillar stage lay their eggs on plants that have co-evolved with their species so the foliage is digestible. (Bee larvae don’t need to work at eating leaves, they grow in cells already provisioned by their parents.)
So gardeners need to find out what species of butterfly or moth are local to their area, which ones need support, and what plants they use as hosts. Below is my list of native pollinator food plants. I cannot pretend to have brought any scientific rigour to my compilation. After all, these are the plants I have chosen to grow, and my casual observation could be skewed by the plants’ location in a spot I visited frequently or seldom, or the time of day and time of year I was around. Still, I can attest to having observed noticeable pollinator interest in these plants.
The advantage for those who live in the Georgian Bay area is that my list is local. And that is an important consideration. But your conditions may differ a little or significantly from mine, even though we are in the same region. One important point made in the BioScience article relates to a shortcoming shared by all lists: the idea that they might be complete. “Lists can implicitly convey the wrong impression—namely, that the plants not included are of little value to pollinators. This is certainly not the case.”
So take my list or any list as a point of departure. In time, you will compile your own. And I, for sure, will make a new list in a few years as I expand the number of plants I am growing. Kate’s top 10 pollinator-friendly plants – all perennial
1. Anise Hyssop (Agastache foeniculum) 80 cm - aromatic foliage - lavender spikes – clumps. Sun
2. New England Aster (Symphyotrichum novae angliae) 100 cm - Pink or purple. Clumps. Sun, part shade
3. Obedient Plant (Physostegia virginiana) 100 cm - mauve spikes – spreads by underground roots. Sun
4. Oswego Tea Beebalm (Monarda didyma) 100 cm – aromatic foliage, bright red flowers - spreads by underground roots. Sun
5. Spotted Joe Pye Weed (Eutrochium maculatum) 180 cm – dusky pink flowers – clumps and self-seeds. Sun
6. Common Milkweed (Asclepias syriaca) 80-100 cm - globes of fragrant dusky pink blooms - spreads vigorously, may not be suitable in small spaces. Sun / shade
7. Flat-topped Goldenrod (Euthamia graminifolia) 4 feet - bright yellow flowers - spreads vigorously, may not be suitable in small spaces. Sun
8. Black Cohosh (Actaea racemosa) 120 cm - finely dissected leaves and creamy flower spikes – clumps. Shade
9. Arrow-leaved Aster (Symphyotrichum urophyllum) 60 cm – small white flowers – clumps. Part shade
10. Purple Coneflower (Echinacea purpurea) 60 cm – pink with bronze centres – clumps and self-seeds. Sun Note: A version of this article (with a different list, for fragrance) appears in the spring edition of Georgian Bay Today. Pollination Station - Return of the Native Special Offer:
Five plants in 10 cm pots for $20. List of plants to choose from includes Anise Hyssop, Obedient Plant, Oswego Tea, Purple Coneflower, Blazing Star and Spotted Joe Pye Weed. On-site demonstration bed. Coming up: WBU Barrie's Plant Day & Sale - June 4, 2017
Return of the Native returns to Wild Birds Unlimited at 515 Bryne Drive, Unit B. in Barrie for a one-day native plant sale on Sunday June 4, from 11 am to 3 pm. Featuring native perennials aimed at attracting birds and pollinators and creating mini-ecosystems in your own backyard. More information to come.