Bulb · Liliaceae
Tulip
Tulipa spp.
Plant them in fall, give them a long cold winter, and tulips open the boldest color of spring.
Full sun
USDA 3–8
9–24 in · 23–61 cm
Overview
Tulips belong to the lily family and trace back to the mountains of central Asia, where cold winters and dry summers shaped how they grow. Each one is a spring-flowering bulb, holding a full season of energy underground until the weather warms. That stored power is why a single bulb can push up a strong stem and a bright cup of color in just a few spring weeks.
The catch is that tulips need a real winter to bloom. A bulb wants 12 to 16 weeks of cold before it flowers, so gardeners in mild zones chill the bulbs first or treat them as a one-season plant. Most modern hybrids fade after a year or two anyway, which is why so many people plant fresh bulbs each fall and enjoy them as a glorious annual.
What you get for that effort is hard to beat. Tulips run from 9 to 24 inches (23 to 61 cm) tall and come in nearly every color, from a 6-inch species tulip to a tall Darwin hybrid. Give them full sun and soil that drains well, and they pay you back with the first big show of the year.
Care
The short version: full sun, fertile soil that drains well, and a bulb planted 6 to 8 inches (15 to 20 cm) deep in fall. Water it in at planting, keep the soil from going soggy, and let the leaves die back on their own after bloom.
Light
Tulips want full sun, ideally 6 or more hours a day, to fuel a strong bloom and recharge the bulb. They take a little partial sun, but too much shade leaves you with weak flowers or none at all.
Water
Water the bulbs in well at planting, then leave them mostly alone. Tulips hate soggy soil, which rots the bulb, so keep them on the dry side once the foliage dies back and the bulb goes dormant.
Soil
Plant in organically rich, fertile ground that drains well. Drainage matters more than anything else here, since a bulb sitting in wet soil will rot long before it gets the chance to bloom.
Humidity
Tulips don't fuss over the air around them, so there's no number to chase. Good drainage and airflow count for far more, since damp, crowded conditions are how tulip fire and bulb rot take hold.
Feeding
Feed a balanced slow-release fertilizer such as a 5-10-5 at planting and again after the flowers fade. Bone meal isn't needed and tends to draw digging animals, so a standard balanced feed is the better choice.
Pruning
Deadhead the spent flowers so the bulb stops spending energy on seed. Leave the foliage in place until it yellows and browns on its own, around late June into July, because cutting it early starves the bulb.
Repotting
Lift and divide a crowded clump every few years once the foliage has died back, then replant the bulbs at the right depth. Crowding shows up as smaller flowers and fewer blooms, or bulbs pushing up toward the surface.
Overwintering
Tulips are hardy in zones 3 through 8 and ride out winter in the ground, where they get the cold they need. In zone 9 and warmer, pre-chill the bulbs for 12 to 16 weeks or replant fresh ones each year.
Size & spacing
Plants stand 9 to 24 inches (23 to 61 cm) tall depending on the type. Set the bulbs 3 to 6 inches (8 to 15 cm) apart and 6 to 8 inches (15 to 20 cm) deep, pointed end up.
When to plant
Tulips run on a backward clock compared to most garden plants. Plant the bulbs in fall before the ground freezes, let them ride out a long cold winter, and the flowers open from April into late May.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Plant: September–November (fall before ground freezes; October ideal)March–May
- Bloom: April–May (early April to late May by division)October–November
Hardiness
USDA hardiness zones: 3–8
Temperature: down to -40°C
Troubleshooting
Most tulip trouble starts underground or arrives on four legs. A bulb that rots, a deer that grazes, or a hybrid that just runs out of steam covers most of what goes wrong. Match what you see below, then act before the problem spreads through the bed.
Scorched, twisted leaves with a fuzzy gray mold
This is tulip fire, caused by the fungus Botrytis tulipae, and it spreads fast in damp, cool, overcast weather. Pull and destroy any plant that shows it, and never plant a bulb with black pinhead specks on its husk. Move the bed to fresh ground and the disease has nowhere to carry over.
Fix:
- Remove and destroy infected plants
- Apply fungicide as leaves emerge
- Discard damaged or spotted bulbs
Soft, smelly bulbs that grow weakly or not at all
This is bulb rot, and wet, poorly drained soil is the usual reason a bulb turns to mush. Dig one up to check, and if the tissue is soft and discolored, throw it out. Fix the drainage before you replant, since a bulb sitting in soggy ground will only rot again.
Fix:
- Discard rotted bulbs
- Improve drainage before replanting
Fresh holes and missing bulbs right after planting
Squirrels, chipmunks, voles, and mice dig up newly planted bulbs, and bone meal in the hole only draws them in faster. Skip the bone meal and lay a sheet of hardware cloth or chicken wire over the bed. A physical barrier stops diggers far better than any repellent.
Fix:
- Cover beds with hardware cloth/chicken wire
- Skip bone meal
Streaked petals and mottled, stunted leaves
Irregular streaks that aren't part of the variety point to tulip breaking virus, which aphids carry from plant to plant. There's no cure, so dig and destroy any plant that shows it, bulb and all. Keep aphids in check to stop the virus before it reaches the rest of the bed.
Fix:
- Dig and destroy infected plants and bulbs
- Control aphids
Plenty of leaves but few or no flowers
Gardeners call these blind tulips, and most modern cultivars fade this way after 3 to 5 years. Cutting the foliage before it dies back starves the bulb, and so does too little sun. Let the leaves yellow on their own, plant in full sun, and swap in fresh bulbs when an old clump quits.
Fix:
- Replace exhausted bulbs with fresh ones
- Let foliage die naturally
- Site in full sun
Shoots, buds, and flowers bitten off in spring
Deer treat tulips as a favorite spring meal, and rabbits browse them too. Repellents help a little, but a hungry deer pushes right past them. A real fence is the only reliable answer, so expect grazed stems if the bed sits open.
Fix:
- Fence or exclude with wire
- Apply repellents (less effective)
Distorted shoots with aphids on the bulbs and leaf bases
The tulip aphid clusters under leaf sheaths, at the base of the plant, and even on bulbs in storage. Those pale-green insects spread the breaking virus, so deal with them early. Dunk infested bulbs in insecticidal soap, and treat growing plants with soap or a stronger spray if the colony holds on.
Fix:
- Immerse infested bulbs in insecticidal soap
- Treat plants with insecticidal soap, pyrethroid or systemic
Fewer and smaller blooms with each passing year
Most modern hybrids decline after the first year, and a warm climate that can't deliver enough winter chill makes the fade worse. Treat hybrids as annuals and replant fresh bulbs, or choose species and Darwin hybrid types that come back better. In mild zones, pre-chill the bulbs before they go in the ground.
Fix:
- Replant fresh bulbs annually
- Choose species or Darwin hybrid types
- Pre-chill bulbs in warm zones
Toxicity
Every part of a tulip is toxic, and the bulb is the worst of it. It concentrates irritant compounds called tulipalin A and B, which upset the stomach in pets and people alike. Keep stored and planted bulbs away from animals and children, and wear gloves when you handle them.
Toxic to
Cats · Dogs · Horses · Rabbits · Livestock · Birds · People
Cats Moderate
Expect drooling, vomiting, and diarrhea, often with a low, dull mood. The bulb is the worst part, so keep stored and planted bulbs well out of reach.
Dogs Moderate
Look for drooling, vomiting, and diarrhea after a dog digs up or chews a bulb. A whole bulb swallowed by a small dog can also block the gut.
Horses Moderate
The bulb brings on an upset stomach and a dull, depressed mood. Keep tulip beds and bulb stores away from where horses graze.
Rabbits Toxic
Tulips hold irritant compounds that rabbits should never eat, and the bulb is the most dangerous part. Fence the plants off and keep bulbs far from any hutch.
Livestock Moderate
Cattle, goats, and sheep can react to the bulbs and foliage with drooling, vomiting, and diarrhea, and larger amounts may bring on heart and breathing trouble.
Birds Toxic
The bulbs and foliage are toxic to birds. Keep poultry and pet birds away from tulip beds and stored bulbs.
People Caution
No part of a tulip is safe to eat, and bulbs are now and then mistaken for onions or shallots. Eating one can cause vomiting and diarrhea, and handling bulbs bare-handed can leave a skin rash, so wear gloves.
Bulb is most toxic; handling bulbs can cause 'tulip fingers' contact dermatitis
Helpline numbers
United States
ASPCA Animal Poison Control: (888) 426-4435 (fee applies)
Poison Control: (800) 222-1222
Canada
Poison Centres: 1-844-764-7669
Varieties
Tulips come in 15 official divisions, but a few classes turn up in most gardens. These are the ones worth knowing by name.
Darwin hybrid
This class carries large, sturdy blooms in mid-spring and lasts the longest while coming back better than other hybrids.
Triumph
The largest class, Triumph gives you classic cup-shaped single flowers in mid-spring across a wide range of colors.
Parrot
Parrot tulips stand out for their fringed, twisted, and feathered petals.
Species/botanical (e.g. Tulipa tarda)
These low-growing tulips live the longest, naturalize on their own, and open white flowers with a yellow eye.
Tulipa batalinii
This species tulip carries soft-yellow single flowers on 6 to 10 inch stems in April.
How to propagate
Tulips multiply on their own underground, and you can speed that along by splitting the bulbs. Growing them from seed is possible too, though it asks for real patience.
Bulbs & cormsModerate
Lift and separate offsets when dormant in summer · 1-3 years to flowering size
Lift a crowded clump while it sits dormant in summer and pull the small daughter bulbs off the parent. Most are too little to flower the first year, so replant them and give them time. They take 1 to 3 years to reach blooming size.
SeedDemanding
Sow ripe seed; mainly for species tulips · 4-7 years to first bloom
Growing tulips from seed is slow work, and it only suits species types. Sow the ripe seed and wait, because a seedling takes 4 to 7 years to bloom. Hybrids don't come true from seed, so what you grow won't match the parent plant.
Myths
Tulips come back bigger and better every year.
Most modern hybrids fade after 1 to 3 years, which is why many gardeners plant them as annuals and start fresh. Species tulips are the ones that truly perennialize.
Plant bulbs as deep as you possibly can.
Aim for about 2 to 3 times the height of the bulb, which works out to roughly 6 to 8 inches. Go too deep and the bulb wastes its stored energy just reaching the surface.
Tie, braid, or cut the foliage right after bloom to keep things tidy.
Leave the leaves alone until they die back on their own and turn brown. Cutting green foliage early starves the bulb and leaves you with blind, flowerless plants next spring.
Bone meal is a must when you plant bulbs.
Most soils already hold enough phosphorus, so bone meal rarely helps, and it draws squirrels and other diggers straight to the bed. A balanced slow-release feed does the job better.
A late spring snow kills tulips that have already come up.
Tulip foliage shrugs off frost and light snow, and that snow even acts as a blanket. Only a hard, bare freeze below the mid-20s°F (about minus 4°C) does real harm.
Sources
- ASPCA Animal Poison Control
- Iowa State University Extension
- Iowa State University Extension
- University of Illinois IPM (Report on Plant Disease 609)
- NIH/NCBI PubMed Central
- Missouri Botanical Garden Plant Finder
- Royal Horticultural Society
- NC State Extension
- Iowa State University Extension
- University of New Hampshire Extension
- University of Georgia Extension
- Iowa State University Extension