CORVALLIS, Ore. – It's not too late in western Oregon to plant spring-flowering bulbs that will infuse color once the gray days of winter retreat.
Plant spring-flowering bulbs from September to December in western Oregon, said Barb Fick, horticulturist for the Oregon State University Extension Service. The optimum planting period depends on the hardiness of each variety. In general, it is best to plant when the soil temperature reaches below 60 degrees Fahrenheit.
Gardeners in eastern Oregon and at higher elevations will want to get their spring-flowering bulbs in the ground as soon as possible, Fick said. September to early November is the best time for eastern Oregon planting.
Plants have evolved several methods of storing food through periods of drought, and the bulb is one of those methods. A true bulb has a hard underground storage structure formed from the plant stem and leaves, according to Fick. Other kinds of storage organs include corms, rhizomes and tubers, which are all types of stem tissue but not true bulbs. Perennial plants that bear buds in underground botanical structures are all known as geophytes, Fick said. It's the cool temperatures of winter that jolt geophytes into producing.
So if you're looking for certain sizes of flowers at the nursery, it follows that "the bigger the bulb, the bigger the flower," said Fick, a horticulture instructor in OSU's College of Agricultural Sciences.
Don't pick bulbs covered with gray mold at the nursery, Fick advised. Plant bulbs as soon as possible after you purchase them so they can establish root systems before the soil freezes or snow covers the ground. If you can't plant in your yard, use potting soil and a container to plant the bulbs, or store bulbs in a cool, dry place, such as a garage or basement.
Here are Fick's recommendations for beautiful and easy spring-flowering bulbs.
- Daffodil — These cheerful white- and yellow- bell-shaped flowers also happen to be deer-resistant. Plus, they require little maintenance. "They're bulletproof," Fick said.
- Tulip — The key to ensuring the continued survival of your tulips? "They will not come back if you water them in the summer," Fick said. "Plant them in a place in your yard where you won't water them in the summer." Tulips, which bloom in mid- to late spring, make a great cut flower in a bouquet, added Fick. She recommends the cultivar "Tulipa clusiana," also known as "Peppermint Stick," for its deep pink and white stripes.
- Crocus — One of the earliest-blooming bulbs, some varieties flower in late winter. The large-flowered Dutch hybrids bloom a variety of colors in early spring. Cultivars that bloom in late winter include Crocus tomasinianus, also known as "Ruby Giant"; Crocus ancyrensis, also known as "Golden Bunch"; and Crocus angustifolius, better known as "Cloth of Gold."
- Hyacinth — With its intense colors and aromas, hyacinths are a spring garden staple. Two of the most recognized species of hyacinth are Hyacinthus orientalis, also known as the common garden hyacinth, and Muscari armeniacum, also known as the grape hyacinth.
- Allium — These pretty, aromatic ornamental onions come in a variety of colors. Some varieties have enormous sizes of flowers, Fick said. They grow from three to four feet tall and are deer-resistant.
- Winter aconite — Known by its scientific name as Eranthis hyemalis, this bright yellow cup-shaped flower appears in late winter an early spring.
For more information, see the OSU Extension publication Propagation of Plants from Specialized Structures.