How to Grow and Care for Tulips

The single most useful thing to know about tulips is that most of them are not really perennials, whatever the packaging implies. Understanding that changes how you plant them and stops you blaming yourself in year three.

The honest answer about coming back

Iowa State Extension is direct: most modern tulip cultivars “bloom well for only 3 or 4 years.” Vigour declines each season until you get large floppy leaves and no flower at all.

That covers most of what is sold — single and double early, single and double late, triumph, parrot and fringed types. Iowa State notes these are, for this reason, often treated as annuals.

Two groups do better:

• Darwin hybrids, the large brilliant-flowered types on stems up to 30 inches, are the longest-performing of the big hybrid tulips.
• Species tulips (also sold as botanical tulips) are smaller, earlier and much more persistent. They are the closest thing to a plant-once tulip.

So decide up front which you are doing. Treating showy hybrids as a three-year display you refresh is a perfectly good plan. Expecting them to behave like daffodils is not.

When to plant

Autumn, and specifically once the soil has cooled. Iowa State gives October as ideal for Iowa, with planting possible as late as December if the ground stays unfrozen.

Do not rush it. Planting in September while the soil is still warm can push foliage up in the fall, which wastes the bulb’s reserves before winter.

How deep, and why it matters

The rule is two to three times the bulb’s maximum diameter — roughly 6 to 8 inches for large tulip bulbs, 3 to 5 inches for small ones.

Shallow planting is the more common error and it has a specific consequence: Iowa State warns that planting too shallowly encourages frost heaving, where freeze-thaw cycles push bulbs up out of the ground and you lose them.

Space large bulbs 4 to 6 inches apart and small ones 3 to 4 inches. Plant in groups of at least 5 to 10 — tulips dotted singly through a border read as accidents rather than a planting.

Site

Full sun gives the best flowers, though tulips tolerate part sun reasonably well.

Well-drained soil is not optional. A tulip bulb is a storage organ sitting underground through a wet winter, and in soil that holds water it rots. If your beds stay soggy, raised beds or containers are a better answer than trying to amend your way out of it.

After flowering, which is where next year is decided

Deadhead the spent flower so the plant does not put energy into seed.

Then leave the leaves alone. Iowa State is explicit that foliage “should not be removed until it has died and turned brown” — often as late as late June or early July. Cutting it early “stops bulb growth and often reduces the number of flowers next spring.”

This is the hard part, because tulip foliage yellows unattractively for weeks in a border that is otherwise looking good. Braiding or tying it does not help; it reduces the light hitting the leaves. The practical solution is to plant tulips behind perennials that leaf out later and hide the mess.

Feed after blooming with 5-10-5 at 2 to 3 pounds per 100 square feet.

Animals

Tulips are palatable to almost everything. Deer and rabbits browse the flowers and foliage; squirrels dig the bulbs, particularly in the weeks after planting when the disturbed soil advertises where they are.

If you have squirrel pressure, firming the soil well and covering new plantings with hardware cloth through the first winter is the practical defence. If you have serious deer pressure, daffodils may be the better plant — they are toxic and generally left alone.

The short version

Plant in October, two to three times the bulb’s depth, in full sun and soil that drains. Buy Darwin hybrids or species tulips if you want them to persist, and anything else if you are happy replanting every few years. Leave the foliage until it browns. Then judge the display on what it is — a spectacular few weeks, not a permanent fixture.