Attracting pollinators: flowers from spring to fall

To feed bees and other pollinators, you don't need a messy garden. What matters is having flowers from spring to fall, without a break.

Wild bees don't store food. A bumblebee queen starts her colony in spring and has to find food every day until the frost. Twenty kinds of flowers that all bloom at the same time feed them for a few weeks. Six kinds that bloom one after another feed them all season.

The two periods short on flowers: April and September

In July, everything blooms. The shortage comes at two times.

In April, when bumblebee queens come out of winter. Most shrubs bloom too late: aronia at the end of May, lilac around May 20, viburnum and ninebark in June. For April, plant instead:

• a pussy willow;
• a serviceberry;
• early bulbs (crocus, scilla, winter aconite), in groups of about fifty.

A maple in the neighbourhood helps too.

In September, when most perennials have gone to seed. Native asters are almost the only flowers that bloom until the frost. Goldenrod and black-eyed Susans cover August and the first half of September. Choose a goldenrod that grows in a clump, like Solidago rugosa 'Fireworks'. Avoid Canada goldenrod (Solidago canadensis): it spreads by its roots and can take over the bed in three years.

Choose single flowers

Double flowers, with lots of petals, are pretty, but they feed bees poorly. Their extra petals often replace the stamens, the part that makes pollen. A "pompom" coneflower, for example, has almost no pollen or nectar left.

How can you tell? A flower that's useful to bees has visible pollen, stamens that stick out, or a raised centre that browns from the bottom up. A tight ball of petals doesn't. Some semi-double flowers keep their stamens: look closely.

Also ask whether the plant was treated. A neonicotinoid insecticide applied while the plant was being grown can stay in the nectar for a season or two, and poison bees even if the flower is single. Once the bed is in place, don't spray anything, not even insecticidal soap, which kills the bees it touches.

Flowers for each period

• April and early May: pussy willow, serviceberry, crocus, scilla, winter aconite.
• Late May and June: aronia, lilac, ninebark, and a viburnum the viburnum leaf beetle leaves alone (Korean spice viburnum, wayfaring tree). American cranberrybush and European cranberrybush are often eaten up by this insect.
• June and July: woodland sage, catmint, speedwell, yarrow, spirea, potentilla (which reblooms until the frost).
• July and August: coneflower, liatris, anise hyssop (Agastache foeniculum). Hybrid agastaches with orange or apricot flowers usually don't survive winter in Quebec.
• August to October: clump-forming goldenrod and black-eyed Susan from August to mid-September, then New England aster and calico aster from mid-September until the frost.

These plants flower better, longer and give more nectar in full sun. This list is for a sunny spot.

Ornamental grasses don't feed bees

Switchgrass, 'Karl Foerster' feather reed grass and miscanthus are pollinated by the wind. They have no nectar, and bees hardly ever seek out their pollen. Keep them anyway: they shelter butterfly caterpillars, and their clumps stay standing for most of the winter.

Leave the stems standing in fall

Most wild bees nest in the ground, but some nest in hollow or soft stems. The female lays her eggs inside, and the larvae spend the winter there. A coneflower stem cut in November and tossed in the compost is a lost nest.

So don't cut back your perennials in fall. Standing stems also hold the snow, which protects plants from the cold. Three exceptions, to cut in October and take out of the garden:

• irises, whose leaves shelter the eggs of a pest insect;
• phlox and bee balm, if they had powdery mildew (a white powder on the leaves);
• peonies.

In spring, cut the stems 30 to 40 cm above the ground, not at ground level: what's left will serve as nests during the summer. Do it once daytime temperatures stay above 10 °C for a week, often in late April, before the new shoots grow tall. The cut pieces still hold last year's bees, which will come out until July. Tie them in a bundle and leave them sheltered behind a shrub for a season. Don't put them in the compost.

Also keep a small patch of bare soil in the sun: mulch everywhere keeps ground-nesting bees from settling in. Leave fallen leaves in a light layer, never packed onto the crowns of plants, or they'll make them rot.

To drink, a bee needs somewhere to land. A plate of water with stones sticking out works well. Empty it every two or three days, more often in a heat wave, to avoid mosquitoes.

How to keep a bed looking tidy

What makes a flower bed look neglected is almost always its edge, not what's in it. Make a clean border, cut straight into the lawn or made of stones, and the bed will look landscaped, even if the plants are tall and loose.

• Plant in groups of three or five of the same kind: bees work one kind of flower at a time, and a group draws them in more.
• Add one or two small conifers (juniper, mugo pine, cedar or dwarf spruce) to keep some shape in winter. Yew only in part shade or out of the wind, otherwise it browns in February.

In short

• Plan for flowers in April (pussy willow, serviceberry, early bulbs) and in September (native asters).
• Choose single flowers and ask whether the plant was treated.
• Don't cut anything back in fall, except irises, peonies, and phlox or bee balm with powdery mildew. In spring, cut at 30 to 40 cm and keep the cut pieces for a season.
• A clean border, plants in groups and one or two conifers give a tidy look.