Squirrel corn (Dicentra canadensis) is a spring ephemeral, similar to the common bleeding heart (Lamprocapnos spectabilis), which once was categorized in the same genus. Squirrel corn fades soon after cool spring weather gives way to summer. Like bleeding heart, it has lacy, fern-like leaves, grayish-green or bluish-green on top, and a lighter green color on the bottom. The 1-inch heart-shaped white flowers hang in terminal clusters at the end of delicate flower stalks, in sufficient numbers to make for a good display if you mass enough of the plants together. Like bleeding heart, squirrel corn is valued for its ability to thrive in shaded conditions.
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.
|Common Name||Squirrel corn|
|Botanical Name||Dicentra canadensis|
|Plant Type||Herbaceous perennial|
|Mature Size||6–12 in. tall and wide|
|Sun Exposure||Partial to full shade|
|Soil Type||Rich, moist but well-drained|
|Soil pH||Acidic to neutral (5.5 to 6.5)|
|Hardiness Zones||3–7 (USDA)|
|Native Area||Eastern, central North America|
|Toxicity||Toxic to humans, animals|
Squirrel Corn Care
Squirrel corn is a North American native plant that is very easy to grow in damp, shady locations that are also well-drained—rocky forest hillsides are a common location for this plant in the wild. Squirrel corn can easily spread and become naturalized if growing conditions are right. It makes for an interesting, unusual addition to woodland gardens and other native-plant gardening garden designs.
With a proper growing environment, squirrel corn requires very little care, but root division every few years will help keep the plant vigorous.
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.
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.
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.
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.
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:
- In early spring before active growth has begun, or immediately after the plants have finished their spring bloom period, use a trowel or shovel to dig up the roots.
- Use your fingers to separate the roots into sections. The tiny corn-like corms can also be broken off from the roots to plant individually.
- Replant the root pieces or small kernel-like corms immediately, no more than 1 to 2 inches deep.
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.
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.
How did squirrel corn get its common name?
The plant gets its common name from the clusters of kernel-like bulblets, that form on its tuberous roots. These roots are often dug up and spread by squirrels and other small animals, which are responsible for spreading the plant.
How do I distinguish squirrel's corn from Dutchman's breeches?
Squirrel corn is closely related to another North American wild plant, Dutchman's breeches (Dicentra cucullaria), and they are sometimes confused with one another. The two plants can be easily distinguished by looking at the flowers (but not their leaves, which are nearly identical): The flower of squirrel corn is heart-shaped, whereas that of Dutchman's breeches looks like an inverted pair of pantaloons. The two also differ in their underground plant parts—those of squirrel corn are yellow and resemble corn kernels, while the corms of Dutchman's breeches are pinkish.
How should I use squirrel corn in the landscape?
Squirrel corn is best suited for a woodland garden or perennial shade garden where you want the novelty of a somewhat unusual plant—you will likely be the only one in your neighborhood growing it. Other native plants you can include around your squirrel corn include:
- 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.
How long does squirrel corn live?
A single squirrel corn plant can live five to eight years, but if you lift and divide the plant every few years, this effectively restarts the clock and allows you to keep clones going for as long as you wish.
Can I transplant wild squirrel corn plants into my garden?
Theoretically, it's possible to dig up squirrel corn plants you find on public lands and move them into your garden. But you should recognize that these plants are considered threatened species in some areas, and there are legal and ethical considerations whenever you move a native plant species from its original habitat. Always check with local authorities on plant-collection restrictions.