SeasonalApr 14, 20266 minby Flora Ashby

Summer-Blooming Bulbs to Plant This Spring

Spring bulbs like tulips and daffodils get all the attention, but summer bulbs are the secret to July and August color. Plant them now for a second wave.

There is a moment in late June when the tulips are a distant memory, the peonies have dropped their petals, and the garden feels like it is holding its breath. This is the gap that summer-blooming bulbs were invented to fill. Plant them in April and May, and by July you will be cutting armfuls of flowers.

Most gardeners know about fall-planted bulbs. Tulips and daffodils go in the ground in October and pop up in spring. But a whole second category of bulbs (really corms, tubers, and rhizomes, but let us not get pedantic) gets planted in spring and blooms in summer. They are the answer to the question, "what should I plant right now for flowers in two months?"

When to plant summer bulbs

The rule is simple: wait until your soil is consistently warm and frost danger has passed. For most of the country, that means mid-April through late May. In zones 3 and 4, you might be waiting until Memorial Day. In zones 8 and 9, you can start in March. If you are not sure whether your last frost has passed, check your zone on our zone map and look up your average last frost date.

You can cheat a few weeks by starting tender bulbs indoors in pots, then transplanting once the weather settles. This is standard practice for dahlias in cold zones. It gives you a head start and earlier blooms.

Dahlias: the flower-farmer obsession

Dahlias are the queen of the summer bulb world. They come in more than 40 named flower forms and every color except true blue, from pompom balls the size of a quarter to dinner-plate blooms the size of your face. One tuber produces dozens of flowers from July until frost. They are the reason flower farmers exist.

Plant dahlia tubers 4 to 6 inches deep in full sun, after all frost danger has passed. Water sparingly until you see green growth, then water generously. Stake the tall varieties early. In zones 7 and colder, dig and store the tubers after the first frost blackens the foliage. In zones 8 and warmer, they can overwinter in the ground with a layer of mulch.

Lilies: the statement bloom

Lilies are the other summer bulb worth building a garden around. Asiatic lilies are the easiest entry point, with upward-facing blooms in vivid oranges, reds, pinks, yellows, and whites. They are unfussy, multiply over time, and bloom in June and July. Plant bulbs 6 to 8 inches deep in spring, in full sun or light shade.

Oriental lilies are the fragrant ones. The classic "Stargazer" and its cousins produce enormous pink and white blooms with a perfume so intense you can smell them from across the yard. They bloom a few weeks later than Asiatics, typically July into August. Plant them at the back of the border where their 3 to 5 foot stems can rise above everything else.

For something wilder, try tiger lily, a native of the Pacific Northwest with spotted orange turk's-cap blooms that hummingbirds visit constantly. All three lily types are deer-resistant, which is unusual for such dramatic flowers.

Crocosmia: the hummingbird magnet

Crocosmia is less famous than dahlias and lilies but just as worth growing. The variety "Lucifer" produces arching sprays of flame-red tubular flowers in July and August, and hummingbirds go absolutely feral for it. The sword-like foliage adds vertical structure before bloom, and the seed heads stay interesting into fall. Hardy in zones 5 to 9.

Plant crocosmia corms 3 to 5 inches deep in full sun, and give them room to clump up. A planting of a dozen corms becomes a stand of hundreds over a few years. If you garden for hummingbirds, this is non-negotiable. See our hummingbird-friendly plants for more companions.

What to plant around your summer bulbs

Summer bulbs shine brightest when layered with other summer bloomers. Plant dahlias behind zinnias and cosmos for a cut-flower bed that produces all summer. Plant lilies among coneflowers and black-eyed Susans for a prairie effect. Plant crocosmia with sunflowers for a bold, hot-colored July border.

If you only have a patio, dahlias and Asiatic lilies both grow beautifully in large containers. A 16-inch pot holds one dahlia or three lily bulbs comfortably. For more container ideas, browse our Container Garden Essentials collection or read our container gardening guide.

The one rule people forget

Summer bulbs are hungry. They are pushing out big flowers on fast-grown stems, and they need fuel. Mix compost into the planting hole, and feed monthly with a balanced fertilizer through the growing season. A neglected dahlia gives you four flowers. A fed dahlia gives you forty.

And cut them. Seriously, cut them for the house, cut them for your neighbors, cut them for strangers. The more you cut, the more they bloom. Dahlias and zinnias especially will produce flowers twice as fast if you keep them harvested. That is the deal. You take the flowers, they make more.