Spring crocus

Year-round

Crocus vernus, often called Dutch crocus or spring crocus, is a small flowering corm originally from mountain meadows in the Alps, Pyrenees, and Carpathians of Europe. It is not native to North America and is grown in home gardens purely as an ornamental plant. It settles in easily almost anywhere with good drainage and some spring sun, and established corms slowly multiply on their own over the years.

• Plant in full sun to light shade with soil that drains well.
• Wet or heavy clay soil is the main cause of corm rot, so avoid low spots that stay soggy.
• Established corms multiply on their own over the years and rarely need replanting.
• Eating any part of the plant can cause vomiting and diarrhea in dogs and cats.
• This is a different plant from autumn crocus (Colchicum autumnale), which blooms in fall and is far more dangerous to pets.

Fall

Fall is planting season for spring crocus in the Columbus area. Get new corms in the ground from mid-September through October so they have time to root before the ground freezes. Crocus corms are also a favorite snack for squirrels, chipmunks, and mice, which is common in Ohio yards, so plan on some protection if that has been a problem before.

• Plant corms about 3 to 4 inches deep, pointed side up, in soil that drains well.
• Aim for mid-September through October in central Ohio, before the ground freezes.
• Choose a spot with good spring sun, crocus bloom before most deciduous trees leaf out.
• Cover new plantings with hardware cloth or a similar barrier if squirrels or chipmunks dig in your yard.
• Space corms in small clusters about 3 inches apart for a fuller look next spring, rather than spacing them out in a thin line.

Fresh, tidy edges around a new fall bulb bed read as HOA-friendly and cared for from the street, which matters if the neighborhood pays attention to fall yard work.

Winter

Crocus corms are cold hardy and handle a normal central Ohio winter without special care once they are established, since Columbus falls well within the range this species tolerates. A newly planted fall bed benefits from a couple inches of mulch to buffer freeze and thaw swings. Seeing a few green tips push up during a warm stretch in January or February is normal for this species.

• No winter watering or fertilizing is needed for established crocus plantings.
• A light 2 to 3 inch mulch layer over a freshly planted fall bed helps guard against corms heaving out of the soil during freeze and thaw cycles.
• Pull mulch back gradually in late winter once the first green tips appear.
• A few leaf tips poking up during a winter warm spell is normal for this species and is not a sign of trouble.

Spring

In the Columbus area, spring crocus is usually the very first flower of the year, often opening in late February or March while a late snow is still possible. Once the blooms fade, the job is mostly to leave things alone. The green leaves that follow are refilling the corm underground for next year's flowers, so they need to stay put and stay in the sun a while longer.

• Expect bloom from late February into March in central Ohio, sometimes pushing right up through a late snow.
• Once flowers fade, pinch or snip off just the dead flower heads so the plant is not putting energy into seed instead of next year's bloom.
• Leave the grass-like leaves alone until they turn yellow or brown on their own, usually by late spring.
• Hold off on the first mow of a crocus lawn area until the foliage has died back naturally.

The leftover green leaves can look a little messy for a few weeks after bloom. That is normal and temporary, and mowing or cutting them too early is the one thing that will cost you next year's flowers. An HOA-friendly middle ground is tucking crocus into a bed edge where the fading leaves are less visible from the street.

Summer

By early summer in the Columbus area, crocus corms have gone dormant underground and the foliage has fully died back. There is nothing to see above ground until fall, so the main task is remembering where the corms are and leaving that patch of ground alone through the hot months. Established plantings do not need summer watering.

• Foliage is usually gone by late May or June, leaving no visible sign of the corms until fall.
• Mark clumps with a small stake or a note on a garden plan so summer digging or planting does not disturb the dormant corms.
• Skip supplemental watering, dormant corms do better on the dry side over summer.
• If a clump has gotten crowded and bloomed less this year, once the foliage has withered is a good time to dig, divide, and replant the corms about 3 to 4 inches deep.