Squirrel corn is best planted in spring from purchased nursery plants in order to ensure first-season blooms. It has a moderate growth rate, and when started from seed will take at least 60 days to reach blooming maturity. A member of the poppy family, squirrel corn is toxic to humans and to animals. Like bleeding heart and dutchman’s breeches, squirrel corn contains isoquinoline alkaloids that can cause neurological symptoms if large quantities are ingested—most commonly by cattle and other grazing animals. Touching the plant can cause skin irritation, but the effect is usually quite short-lived. With a proper growing environment, squirrel corn requires very little care, but root division every few years will help keep the plant vigorous.
Light
Squirrel corn performs best in a partial shade or full shade location. Too much direct sun will inhibit flowering and hasten the onset of summer dormancy.
Soil
Grow squirrel corn in consistently moist but well-drained soil that is high in organic material. Well-drained loamy soil is ideal, but this plant will do well in relatively rock soil if it has a high ratio of moisture-retentive organic matter.
Water
Squirrel corn is a spring ephemeral that must be kept moist during the spring active growing season but can be allowed to go dry as the hot months of summer begin. If rainfall is not plentiful in spring, make sure it gets at least 1 inch of irrigation per week, best delivered in smaller waterings spaced a few days apart. Do not, however, let the roots soak in permanently soggy soil.
Fertilizer
In decently fertile soil, squirrel corn will do nicely if you simply amend each year with a good amount of compost dug into the soil. Additional feeding is needed only in very barren soils.
Types of Dicentra
Squirrel corn (Dicentra canadensis) is a native North American wildflower, and there are no additional named cultivars offered in the trade. However, there are several other Dicentra species native to North America that wildflower enthusiasts sometimes grow:
Dicentra cucullaria (Dutchman’s breeches) is native to eastern North America and has a very similar look to squirrel corn.Dicentra eximia is often known as fringed bleeding heart or turkey corn. It is native to the Appalachian Mountains.Dicentra formosa, or western bleeding heart, is native to the Pacific coast regions of North America.Dicentra nevadensis , Sierra bleeding heart, is native to the central region of eastern California.Dicentra pauciflora is native to California and Oregon.
Pruning
The foliage and flower stalks of this spring ephemeral should be cut back to ground level as the plant fades with the approach of summer heat. The plant will return nicely the following spring.
How to Propagate Squirrel Corn
Squirrel corn is best propagated by digging up and dividing the tuberous roots and small kernel-like corms attached to the roots. Here’s how:
Potting and Repotting Squirrel Corn
As a spring ephemeral, squirrel corn is not a popular container plant, though it is possible to grow it in pots using any well-draining pot filled with commercial potting soil, preferably blended with good, rich compost. When the plant goes dormant in summer, you’ll need to move the container to an out-of-the-way location where it can be sheltered through the winter before the next spring’s growth begins.
Overwintering
If you have not done so after the plant goes dormant in summer, cut the stems down to 1 to 2 inches above ground level. Withhold water as winter approaches. In cold winter zones (zones 3 and 4) at the start of the winter season, you can protect the roots and help them retain moisture by adding a two-inch layer of mulch on top of the plant stems. Remove the mulch as the frosty season ends.
Common Pests and Plant Diseases
Squirrel’s corn is largely free of pest and disease issues, but it can be visited by some of the same problems that bleeding heart experiences:
Aphids and scale can be treated with insecticidal soap or neem oil. Slugs and snails are combatted by physically picking them off by hand, or by setting baits. Fungal infections, such as leaf spot, root rot, and powdery mildew can be treated with fungicides, though often plants will recover nicely with no attention at all. A plant that has turned foul and black has developed rot and should be removed and thrown out.
How to Get Squirrel Corn to Bloom
Squirrel corn normally begins blooming in spring and will continue until temperatures grow too warm, usually fading by early summer. Hot weather will trigger dormancy in the plant, and the foliage will turn yellow and die back.
If the plant fails to flower, it may simply be too young and immature to bloom. It’s not uncommon for squirrel corn to take a full year before it blooms.A mature plant may begin to withhold blooms when its roots become too overgrown. Lifting and dividing the roots will usually return such a plant to vigor.Make sure the plant gets adequate shade. Too much sun will prevent it from flowering.
Common Problems With Squirrel Corn
Native wildflowers such as squirrel corn are free of many of the cultural problems that can plague more aristocratic plants, but gardeners sometimes complain about a couple of issues with squirrel corn:
Empty Spots When Plants Fade
Because it is a spring ephemeral, squirrel corn does die back in summer. If you want to avoid having the resulting gap in your shade garden, be ready to have other plants take the place of your squirrel corn plants when they go dormant. There are two solutions to the gap problem:
Plant impatiens (Impatiens walleriana) or other shade-loving annual plants around the area vacated by your dormant squirrel corn. These annuals will provide color in summer and then die back in the fall, leaving the space clear again for the squirrel corn re-emerging in spring. For a longer-lasting solution, grow other shade perennials around the area that will fill in and bloom later than your squirrel corn.
Rapid Wilting and Dieback
It’s normal for squirrel corn to die back as mid-summer begins, but this process is usually fairly gradual. If the plant dies back quickly and earlier than you expect, it’s likely that excessively wet conditions will cause serious root rot or other fungal disease to set in. Diseases such asverticillium wilt, fusarium wilt, and botrytis will cause very rapid decline of the plant. There is usually no recovery at this point, and the best approach is to remove the plant and destroy it before the fungal disease can spread.
Round-lobed hepatica (Hepatica americana)Bloodroot (Sanguinaria canadensis)
All three are native perennials in eastern North America, require the same sun and soil conditions, and bloom in mid-spring. Be aware of this plant’s ephemeral nature, and design your garden so the empty space left when squirrel corn goes dormant in summer will be hidden by other plants.
