Q: I ordered a whole bunch of native perennial plants that are supposed to be good for pollinators, and they’ll arrive this week. Can you tell me how I should plant them? The big question I have is whether I should plant them in mixed rows, or whether I should plant all the flowers of one kind together. It seems like I see it both ways in other people’s gardens.
A: What a good question.
Planting in clusters is better to help pollinators and from a garden design perspective. It looks nicer to have swaths of color rather than a mishmash, and bees, hummingbirds and other pollinators like it better, too.
It’s easier for our native bees and other pollinators to find the flowers they need if there’s a swath of them, rather than an individual flower here and there. It’s also more efficient for them to forage a larger area of a single type of flower, especially for the pollinators that prefer to get their nectar and pollen from a specific species of flower.
Ideally, you want each clump of plants to fill a space at least 3 square meters, which is the equivalent of a square that is a little over 5½ feet on each side.
When you’re planting, pay attention to how big the plants are going to get. One of the most common mistakes gardeners make is planting according to the size that a plant, tree or shrub is when it arrives, rather than the size it will be fully grown. Think about the heights of the plants, too. You want the taller ones where they won’t shade the shorter ones too much.
It sounds like you’ve already chosen your plants, but for folks who are still designing their pollinator garden: Choose plants so that you have something in bloom spring, summer and fall. Try to use mostly native plants, which are often preferred by our native pollinators, but it’s all right to fill in with some non-native species.
Many pollinators love catmint, for example, and Autumn Joy sedum will be buzzing with pollinators in fall. It’s OK to add some annuals, too, such as zinnias, so you have something blooming right away.
In general, you want to choose annual flowers that have single blooms. The ones that have been bred to have double blooms often offer less in the way of pollen and nectar.
There’s a list of annuals for pollinators at
extension.umn.edu/yard-and-garden-news/annual-flowers-pollinators
and there’s tons more information about planting for pollinators at
beelab.umn.edu/plant-flowers,
including a useful list of perennials for bees.