For flowers that bloom in the spring, such as tulips and daffodils, you should plant bulbs in the previous fall. But bulbs for summer-blooming plants like dahlias, gladiolus, begonias, lilies, cannas and calla lilies should be planted in the spring, as soon as the soil is warm enough to work.
The myriad varieties of these show-stopping members of the daisy family produce flowers that measure anywhere from a few inches to a foot across, on plants that stand from 10 inches to 3 feet tall. They will be the first of your spring-planted bulbs to reward your efforts, blooming in late April or May.
According to Dutch Gardens, dahlias are hardy in U.S.D.A. zones 8 through 10, though they may survive in zone 7 under a thick layer of mulch. In less temperate zones, you’ll have to dig the tubers up, dry them and store them over the winter for planting again in the spring.
No doubt you’ve seen these tall, spiky flowers in hundreds of floral arrangements and bouquets. Gardeners prize gladiolus for their upright habit and the dozens of colors they come in. Glads will start to bloom in June. They are winter hardy as far north as U.S.D.A. zone 7, so again, if you live in a colder zone, you’ll have to take the corms inside for the winter.
Tuberous begonias are shade-loving plants that come in a vast array of colors, with soft, almost roselike blossoms. Native to the Andes, they won’t tolerate desert conditions, nor will they survive the winter in zones less temperate than 9 or 10. It can take as long as 3 months from the time you plant the tuber for the begonia to bloom, so Dutch Gardens recommends that you start the plant inside at least a month before you’d like to see it blossoming in your garden.
These beautiful flowering plants, with their graceful, fragrant blossoms atop tall stems, are among the toughest you can add to your garden; many varieties are hardy as far north as zone 4. Asiatics bloom first, in the early summer, followed by trumpet lilies, tiger lilies and rubrum lilies in midsummer. Oriental lilies flower at the end of the summer and into the early fall. By mixing up the varieties that you plant in a single flower bed, you can guarantee you’ll have lilies blooming there from early summer till nearly frost.
Cannas are tropical flowers that are hardy in zones 9 and 10. They have big, splashy blossoms and showy foliage, and different varieties grow from 2 feet to more than 10 feet tall. You can use the tall varieties to create bright focal points in your garden, or mix the dwarf versions in with other low-growing plants.
Their tight, pitcher-shaped flowers make these lilies a popular addition to floral arrangements. The plants love shade, so they do well under trees or in shade gardens. They bloom in the late summer, and are only hardy in zones 9 and 10. You should plant them inside and then move them outside as soon as the danger of frost has passed, to give them a head start on the growing season.