Ranunculus
The ideal planting time for ranunculus depends on your zone.
Zones 8-10 can plant ranunculus bulbs in autumn for blooms in late winter and early spring.
Zones 2-7 should plant in late winter or early spring, once the threat of hard frost is over.
If you aren’t ready to plant the Ranunculus corms when you receive them, simply keep them in a
cool dry place for up to eight months.
If corms are exposed to temperatures below 25°F, they will freeze and ultimately rot once they
thaw.
In all but the coldest climates, you can protect your ranunculus corms with a low tunnel or
greenhouse, and cover the planting area with 3” of mulch or straw. Remove mulch in spring after
last hard freeze.
Soak the bulbs for 2 hours or until double in size (do not oversoak) in lukewarm water before
planting to add moisture back to the bulb; this helps to jump start rooting. Choose well-draining
soil with full sun exposure. Dig holes that allow you to plant the ranunculus 2 inches deep, and 6
to 9 inches apart. Make sure the “pointed” ends are facing downward. After planting, gently soak
the soil.
Gardeners in zones 4-6 who do not have a low tunnel or greenhouse should soak and pre-sprout
the corms four weeks before the last frost date. Pre-sprouting ranunculus will allow your corms
to bloom a few weeks earlier than normal.
Soak corms in room-temperature water for two hours. Fill a seed tray half-way with moist potting
soil.
Place corms in the tray and cover with more soil. Move the tray into an area that has good air
circulation and consistent temperatures of 40 to 50°F for two weeks.
Check the corms every three to four days to ensure the soil is moist, and remove any corms that
show signs of rotting or molding. Once rootlets appear, it’s time to plant.
