MDC offers tips for native plants prone to frost flowers

Kansas City, Mo. – Icy blooms, often called frost flowers, are appearing this winter at the Missouri Department of Conservation's (MDC) Anita B. Gorman Discovery Center. Frozen, twisted ribbons of ice arose on the lower stems of white crownbeard, a native wildflower planted in the Center's outdoor garden. Good soil moisture and cold temperatures have produced numerous frost flowers on white crownbeard in recent months.

Only a few plants in Missouri are prone to frost flowers. White crownbeard, yellow crownbeard, yellow ironweed and dittany will have frost flowers if conditions are right. Scientists are unsure why only these plants produce crystal ice patterns into ribbons or clusters that resemble flowers. One theory is that their root systems stay active pulling up moisture from the soil, even though the upper parts of the plants go dormant in autumn. Another theory is that their stems rupture and crack in just the right way so sap oozing out forms into wide ribbons that freeze into the ice patterns.

Frost flowers often appear on plants like crownbeard in late autumn or early winter when a sudden cold snap follows conditions that have kept soil moist and warm. Some descriptive accounts found on the Internet cite frost flowers as rare and often vanishing quickly as sunlight strikes them. This is often true.

However, frost flowers have appeared with regularity on white crownbeard stems the past few years in the Gorman Discovery Center's prairie garden, part of the Center's outdoor teaching area. Frost flowers have appeared during the first hard freeze, melted during warm ups, and reappeared during subsequent freezes. They have lingered for days in areas shaded from the sun if temperatures stayed at freezing or below.

Home gardeners can enjoy frost flowers by adding plants such as white crownbeard to gardens or native plant landscaping. White crownbeard, also called frostweed, produces clusters of white flowers from August into October. They are tall plants and can reach 7 feet with enough sunlight or good soil, so they should be placed in gardens accordingly. Dittany is a smaller plant that produces purple flowers and may fit better in smaller, shaded yard plantings.

These native plants also benefit important pollinator species such as butterflies, moths and bees. Both white crownbeard and dittany bloom late into the growing season, a help to migrant species.

Winter brings stillness to gardens as green plants fade to browns and insects no longer buzz about. But on certain plants the cold brings forth delicate white ice patterns. Planting these species this spring can provide a chilled bonus bloom in winter.

For information on frost flowers and plants that produce them, visit mdc.mo.gov/node/25335.

Information about using native plants in landscape gardens is available at grownative.org.

Visitors are welcome year round at MDC's Gorman Discovery Center, http://mdc.mo.gov/node/281.