Are Tulips & Daffodils Frost Tolerant?
Winter seems to slip into spring almost unseen some years. The north wind brings frost one day, and the next day tulips (Tulipa spp.) and daffodils (Narcissus spp.) are popping up. Too often, though, one last frost or even a few more inches of snow spoil a gardener's fun. Fear not: A light frost won't hurt tulip or daffodil plants. In fact, they need a bit of chilling to bloom their best.
Tough Spring Bulbs
Hardy spring bulbs such as tulips and daffodils survive frozen ground where air temperatures dip to minus 40 degrees Fahrenheit. Some other bulb plants even bloom through snow, leading the way in spring. Provided they are not in bloom, tulips and daffodils are tough enough to survive a few nights of light frost. A coating of snow may weight them down or break their emerging stems, but won't kill the bulbs. Tulips are hardy in U.S. Department of Agriculture plant hardiness zones 3 through 8, depending on type, and daffodils are hardy in USDA zones 4 through 8, depending on cultivar.
Survival Characteristic
Aside from their hardiness, tulip and daffodils share the common trait of growing from bulbs, which are modified roots adapted to protect and feed the plants in unpredictable periods of time, such as during extreme cold. Each bulb grows a layer of tissue as an embryonic plant, complete with flower.
As the days lengthen in spring and the ground thaws, the plants emerge from the bulbs on a schedule determined by evolution. Provided bulbs are planted under 6 to 8 inches of loamy soil and the soil remains moist but not soggy, the bulbs have the conditions necessary to emerge on a day when the environmental odds are in their favor.
Spring Companions
Tulips and daffodils are suitable companions in a spring garden. Both naturalize easily, growing in drifts. Early daffodils typically bloom before early tulips, providing up to two months of color beginning in March or April and ending in April or May, depending on the latitude.
Species tulips return year after year more easily than hybrids, and division adds longevity to daffodil bulbs, which tend to reproduce every three to five years. When the number of blooms declines, simply dig up the old bulbs and either plant new bulbs or divide the old bulbs, and store them when dry in a refrigerator until fall planting time.
Give your tulips and daffodils the best positions to minimize the effects of sudden spring frosts and freezes. Plant their bulbs on your home's north or east side, where sunlight doesn't heat the soil as fast as it does on south and west sides.
In Case of Extremes
Although tulips and daffodils are cold-tolerant, temperatures below 29 degrees Fahrenheit can damage their tender buds and flowers. An extended hard freeze can damage whole plants. Because next year's plants are forming within the bulbs, though, cold damage may be limited to this year's growth.
If a hard freeze is forecast after tulip and daffodil plants emerge above soil in spring, then cover the plants with a cloth sheet. Cloth insulates — as long as it doesn't touch the plants — and holds in ground warmth.
References
- U.S. Department of Agriculture: USDA Plant Hardiness Zone Map
- Missouri Botanical Garden: Tulipa (Group)
- Missouri Botanical Garden: Narcissus (Group)
- Missouri Botanical Garden: Narcissus 'King Alfred'
- Missouri Botanical Garden: Narcissus 'La Belle'
- University of Illinois Extension: Bulbs and More — Questions and Answers
- North Dakota State University Extension Service: Hortiscope — Questions on Tulips
- PlantTalk Colorado: Spring Frosts and Snows
- University of Illinois Extension: How Plants Are Affected by Cold and Winter and How to Protect Them