Tulips (Tulipa spp) - Key Growing Information
DAYS TO GERMINATION:
Plant the bulbs in fall for flowers in spring.SOWING:
Plant soon after the bulbs arrive (or right after prechilling), once the soil has cooled to 55°F (13°C) or below and nights are reliably 40–50°F (4–10°C), but before the ground freezes. Planting about 5–6 weeks ahead of freeze-up gives the bulbs time to root. Store Bulbs if you can't plant right away: If you can't plant right away, you can hold bulbs for up to a month. Open all bags and boxes and keep the bulbs somewhere cool, dark, dry and airy, such as a root cellar, basement or garage. The refrigerator crisper also works, but not alongside ripening fruit: ethylene from apples and other fruit can kill or deform the flower inside the bulb. Anywhere from 38 to 65°F (3–18°C) is fine; cooler is better, but don't let them freeze. Note on Tulips in Hardiness Zones 8–10: Tulips need a cold period while dormant to form flowers. We don't currently sell prechilled bulbs, so in Zones 8–10 you'll need to chill them yourself at 38–45°F (3–7°C) for 6–12 weeks before planting. Leave the bulbs in their bags in the refrigerator for up to 12 weeks, away from fruit, especially apples. Plant right after chilling, during the coolest part of the year. In Zones 9–10, where winters aren't cold enough, prechilled bulbs will bloom only once, the spring after planting. Planting Bulbs: Loosen the soil 8–12" deep so roots can establish, and work some compost into the root zone to help roots and growth. Press each bulb in upright, pointed end up and flat base down, and cover it with soil 2½–3 times as deep as the bulb is tall, a little deeper in light soil; a 1½" bulb, for example, needs 4–5" of soil on top. When in doubt, err on the deep side. Planting all bulbs at the same depth helps them bloom together. Water right after fall planting; after that, normal rain is enough except in the driest climates. Mulch: Mulch isn't required, but 2–4" of chopped straw, shredded leaves or pine bark helps hold moisture, keep the soil cool and block weeds. Wait until the ground has frozen to apply it, since mulching while the soil is still warm can damage bulbs. Pull it back in early spring, as leaving it on delays flowering.LIGHT PREFERENCE:
Full sun is best, though tulips cope with some shade, especially in hot weather. They need at least 5–6 hours of sun a day while blooming.PLANT HEIGHT:
Depends on the variety.PLANT SPACING:
For annual cut-flower crops, set bulbs ¼–½" apart, packed like eggs in a carton, as close as possible without touching. In landscape or garden beds, space them 1–6" apart.HARDINESS ZONES:
With some exceptions, many hybrid tulips don't come back reliably year after year, so cut-flower growers often treat them as annuals; see each product description for details. Parrot tulips do best in Zones 4–7, and Double Late, Single Late and Darwin Hybrid tulips in Zones 3–7. Darwin Hybrids often perennialize, depending on care and location. To grow tulips as perennials, remove spent flowers but leave the stems and leaves until they yellow or brown and die back on their own.STEM LENGTH:
Depends on the variety.VASE LIFE:
Lasts about 10 days. Tulips "walk" in the vase: stems keep growing and bend toward the light, so the flowers shift position over time.STORAGE TEMPERATURE:
Store cut flowers at 32–35°F (0–2°C).HARVEST:
Cut when the buds show color but before they start to open. For the longest stems, reach down to the base and pull straight up, which adds 3–6" compared with cutting at the soil line. For longer holding, lift the whole plant, bulb and all, with a garden fork; the attached bulb feeds the flower in storage. Keep stems straight in storage by standing them upright or bunching and wrapping them in paper. In home gardens where you want tulips to return, leave the foliage when picking, since the plant needs its leaves to build energy for next year's blooms.Deadhead any flowers you don't cut, and don't mow the foliage until it has turned brown. Keep cut stems in plain, clean water.
SOIL:
Bulbs need well-drained soil with a pH of 6.0–7.0. Amend according to a soil test to correct pH and improve drainage; raised beds or added compost help drainage. Avoid excess nitrogen and fresh manure.NOTES:Our bulbs are 12 cm or more around the middle, known as "top size," the standard for cut-flower and garden tulips. Inspecting your Bulbs: You may see a little blue mold (Penicillium) on the outside of the bulbs. This is normal and rarely harms the bulb or your soil. Small scuffs or scars from harvest, or an incomplete outer skin, are also common and won't affect performance.
PESTS AND DISEASES
Botrytis blight (Botrytis tulipae), also called tulip fire, is a fungus that causes soft brown spots on leaves, stems and flowers and can spread fast, killing many plants. Lower the risk by planting in well-drained soil without crowding, avoiding excess nitrogen, which weakens plants, and clearing crop debris every year. Destroy infected plants and keep tulips out of infected soil for at least 2 years. Aphids can feed on plants and spread viruses; control them with horticultural soap or, in a greenhouse, the parasitic wasp Aphidius.
Scientific Name:
Tulipa spp.
