Bulb · Liliaceae
Tulip
Tulipa spp.
Set in the ground each fall and carried through a long cold winter, tulips open as the spring garden's first grand gesture of color.
Full sun
USDA 3–8
9–24 in · 23–61 cm
Overview
The tulip belongs to the lily family and first grew wild across the mountains of central Asia, where cold winters and dry summers set its habits. Each one is a spring-flowering bulb that keeps a full season of energy tucked underground until the weather turns. That hidden reserve is what sends up a sturdy stem topped with a clean cup of color over just a few spring weeks.
The one condition tulips insist on is a real winter. A bulb needs 12 to 16 weeks of cold before it will flower, so gardeners in mild zones chill the bulbs first or enjoy them for a single season. Most modern hybrids fade after a year or two regardless, which is why many people plant fresh bulbs each fall and treat the display as a glorious annual.
The payoff sits at the heart of the spring garden. Tulips rise 9 to 24 inches (23 to 61 cm) tall and come in nearly every color imaginable, from a low 6 inch species tulip to a stately Darwin hybrid. Give them full sun and free-draining soil, and they deliver the season's first great show of color.
Care
The short version: tulips want full sun and fertile, free-draining soil, with each bulb set 6 to 8 inches (15 to 20 cm) deep in fall. Water them in at planting, keep the ground from turning soggy, and let the leaves die back on their own once the blooms have passed.
Light
Tulips are at their best in full sun, ideally 6 or more hours a day, which fuels a strong bloom and restocks the bulb for next year. A touch of partial sun is tolerated, though deep shade tends to leave thin flowers or none at all.
Water
A good soak at planting is all the bulbs really ask for, and then they prefer to be left alone. Soggy soil is the real enemy, since it rots the bulb, so keep things on the dry side once the foliage fades and dormancy sets in.
Soil
Choose fertile, organically rich ground that drains freely, and the hardest part is done. Drainage outranks every other consideration here, because a bulb sitting in wet soil rots long before it has a chance to flower.
Humidity
The air around tulips needs no attention, and there is no target number to aim for. What matters far more is good drainage and airflow, since damp, crowded settings are where tulip fire and bulb rot take hold.
Feeding
A balanced slow-release fertilizer such as a 5-10-5 suits them well, applied once at planting and again after the flowers fade. Bone meal is not needed and tends to invite digging animals, so a plain balanced feed is the wiser pick.
Pruning
Remove the spent flowers so the bulb stops investing energy in seed. Leave the foliage in place until it yellows and browns on its own, usually around late June into July, since cutting it early leaves the bulb underfed.
Repotting
Every few years, once the leaves have died back, lift a crowded clump and divide it, then replant the bulbs at their proper depth. Crowding announces itself as smaller flowers and fewer blooms, or bulbs working their way up toward the surface.
Overwintering
Tulips are hardy in zones 3 through 8 and spend winter in the ground, where they collect the chill they depend on. In zone 9 and warmer, give the bulbs a pre-chill of 12 to 16 weeks or simply replant fresh ones each year.
Size & spacing
Depending on the class, tulips stand 9 to 24 inches (23 to 61 cm) tall. 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 keep the garden's calendar in reverse, and that suits a seasonal home beautifully. The bulbs go in during fall before the ground freezes, rest through a long cold winter, and open from April into late May, right when a space is ready for color again.
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 of what troubles a tulip happens out of sight at the bulb or arrives on four legs across the garden. A rotting bulb, a grazing deer, or a tired hybrid past its prime accounts for most of it. Match the sign below and step in early, before it moves through the planting.
Scorched, twisted foliage under a gray fuzz of mold
Those symptoms point to tulip fire, the fungus Botrytis tulipae, which races through damp, cool, overcast spells. Lift and destroy any plant that shows it, and never set out a bulb marked with tiny black pinhead specks on its husk. Move the planting to fresh ground and the disease has nowhere left to linger.
Fix:
- Remove and destroy infected plants
- Apply fungicide as leaves emerge
- Discard damaged or spotted bulbs
Soft, foul-smelling bulbs that barely grow
This is bulb rot, and wet, badly drained soil is nearly always the cause of a bulb gone to mush. Dig one up to check, and if the tissue is soft and discolored, discard it. Correct the drainage before replanting, because a bulb left in soggy ground simply rots again.
Fix:
- Discard rotted bulbs
- Improve drainage before replanting
New holes and missing bulbs just after planting
Squirrels, chipmunks, voles, and mice unearth freshly planted bulbs, and bone meal in the hole only speeds their arrival. Skip the bone meal and lay hardware cloth or chicken wire over the bed. A solid barrier turns diggers away far better than any repellent.
Fix:
- Cover beds with hardware cloth/chicken wire
- Skip bone meal
Streaked petals with mottled, stunted leaves
Irregular streaks that belong to no variety usually signal tulip breaking virus, ferried plant to plant by aphids. There is no cure, so dig up and destroy anything affected, bulb included. Keeping aphids down is the surest way to halt the virus before it spreads across the bed.
Fix:
- Dig and destroy infected plants and bulbs
- Control aphids
Full foliage yet few blooms or none
These are blind tulips, the way most modern cultivars fade after 3 to 5 years. Cutting the leaves before they die back starves the bulb, and so does too little sun. Let the foliage yellow at its own pace, plant in full sun, and bring in fresh bulbs once an old clump is spent.
Fix:
- Replace exhausted bulbs with fresh ones
- Let foliage die naturally
- Site in full sun
Shoots, buds, and flowers grazed off in spring
To deer, tulips are a prized spring meal, and rabbits browse them just as readily. Repellents offer modest help, but a hungry deer walks straight through them. A real fence is the only dependable defense, so expect nibbled stems where a bed sits unprotected.
Fix:
- Fence or exclude with wire
- Apply repellents (less effective)
Distorted shoots and aphids on bulbs and leaf bases
The tulip aphid gathers beneath leaf sheaths, at the base of the plant, and on bulbs kept in storage. These pale-green insects carry the breaking virus, so early action pays off. Immerse infested bulbs in insecticidal soap and treat growing plants with soap, or something stronger if the colony holds on.
Fix:
- Immerse infested bulbs in insecticidal soap
- Treat plants with insecticidal soap, pyrethroid or systemic
Fewer, smaller blooms with every season
Most modern hybrids fade after their first year, and a warm climate short on winter chill deepens the slide. Treat hybrids as annuals and replant fresh bulbs, or rely on species and Darwin hybrid types that return more dependably. In mild zones, pre-chill the bulbs before they go in.
Fix:
- Replant fresh bulbs annually
- Choose species or Darwin hybrid types
- Pre-chill bulbs in warm zones
Toxicity
For all their elegance, tulips are toxic in every part, and the bulb holds the most of it. Those bulbs carry irritant compounds called tulipalin A and B, which upset the stomach in pets and people alike. Store and plant them where animals and children cannot reach, and slip on gloves before handling.
Toxic to
Cats · Dogs · Horses · Rabbits · Livestock · Birds · People
Cats Moderate
A cat that samples a tulip may drool, vomit, and pass diarrhea, often turning quiet and low in mood. The bulb is the harshest part, so keep stored and planted bulbs well beyond a cat's reach.
Dogs Moderate
Drooling, vomiting, and diarrhea tend to follow when a dog digs up or chews a bulb. A whole bulb swallowed by a small dog can also block the gut, so treat it seriously.
Horses Moderate
The bulb tends to bring on an upset stomach and a flat, dull mood. Keep tulip beds and stored bulbs away from where horses graze.
Rabbits Toxic
Tulips hold irritant compounds that rabbits should never eat, with the bulb the most dangerous part. Fence the plants off and keep every bulb far from the hutch.
Livestock Moderate
Cattle, goats, and sheep may react to the bulbs and foliage with drooling, vomiting, and diarrhea, and a larger dose can bring on heart and breathing trouble.
Birds Toxic
Both bulbs and foliage are toxic to birds. Keep poultry and pet birds away from tulip beds and any stored bulbs.
People Caution
No part of a tulip is safe to eat, and the bulbs are occasionally mistaken for onions or shallots. Eating one can cause vomiting and diarrhea, and handling bulbs bare-handed may leave a 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 are organized into 15 official divisions, though only a handful of classes turn up in most gardens. These are the ones worth knowing when planning a season of color.
Darwin hybrid
This class carries large, sturdy blooms in mid-spring, lasts the longest, and returns more reliably than other hybrids.
Triumph
The largest class, Triumph offers classic cup-shaped single flowers in mid-spring across an unusually wide range of colors.
Parrot
The flamboyant ones, Parrot tulips show fringed, twisted, and feathered petals.
Species/botanical (e.g. Tulipa tarda)
These low-growing tulips last the longest, spread on their own over time, and open white flowers with a yellow eye.
Tulipa batalinii
A species tulip, this one opens soft-yellow single flowers on 6 to 10 inch stems through April.
How to propagate
Tulips increase quietly underground, and a gardener can help the process along by dividing the bulbs. Starting from seed is possible as well, for anyone with the patience to wait on it.
Bulbs & cormsModerate
Lift and separate offsets when dormant in summer · 1-3 years to flowering size
When a clump turns crowded, lift it during its summer dormancy and separate the small daughter bulbs from the parent. Most are too small to flower right away, so replant them and let them build up. Expect 1 to 3 years before they reach blooming size.
SeedDemanding
Sow ripe seed; mainly for species tulips · 4-7 years to first bloom
Raising tulips from seed is slow, patient work best suited to species types. Sow the ripe seed and settle in to wait, since a seedling needs 4 to 7 years to bloom. Hybrids will not come true from seed, so the result rarely resembles the parent.
Myths
Tulips return larger and finer every single year.
In reality, most modern hybrids fade after 1 to 3 years, which is why many gardeners plant them as annuals and begin again. Species tulips are the ones that truly perennialize.
Plant the bulbs as deep as you can manage.
Aim instead for about 2 to 3 times the height of the bulb, roughly 6 to 8 inches. Set too deep, a bulb burns its reserves just reaching the surface.
Tie, braid, or cut the leaves right after bloom for a tidy look.
Leave the foliage be until it dies back on its own and turns brown. Cutting green leaves early starves the bulb and yields blind, flowerless plants next spring.
Bone meal is essential every time you plant bulbs.
Most soils already carry ample phosphorus, so bone meal rarely helps and leads squirrels and other diggers to the bed. A balanced slow-release feed does the job better.
A late spring snow finishes off tulips that have surfaced.
Tulip foliage shrugs off frost and light snow, and the snow even acts as a blanket. Only a hard, bare freeze below the mid-20s°F (about minus 4°C) causes 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