It is no wonder how the old-fashioned common bleeding heart plant got its name. The pillow-like flower is heart-shaped with a single dangling pendulous drop. In addition to the common bleeding heart, there are also a handful of other species in the Dicentra genus that go by the name bleeding heart, though these are mostly wildflowers that aren’t commonly grown in cultivation.
Bleeding hearts are shade-loving woodland plants that bloom in the cool of spring. Although they stay in bloom for several weeks, the plants often become ephemeral, disappearing for the rest of the summer if exposed to too much sun or heat. The roots are still alive, though, and the plant will regrow in the fall or the following spring. The fringed-leaf varieties of bleeding heart repeat-bloom throughout the summer.
Starting cuttings or new plants is best done in spring to early summer. These plants will also self-seed if the flowers are not deadheaded. Bleeding heart has a medium growth rate and reaches its mature size in about 60 days.
In a typical growing season, a bleeding heart plant produces about 20 small flowers on each of its stems in spring. Its foliage usually enters dormancy in the midsummer heat. This sensitivity to heat makes establishing new plants more challenging in warmer zones than in colder areas. In addition, the flowers are delicate and should be protected from strong winds.
Bleeding hearts will stay in bloom for several weeks, but the foliage tends to go downhill after flowering. Plan to have late-emerging plants nearby to fill in the hole if your bleeding hearts go dormant and disappear. Coral bells, ferns, foam flower, hosta and monkshood are good companions.
Bleeding heart does best in part shade. Since it is such an early bloomer, planting near a deciduous tree is a good spot. The plant will be up and growing before the tree leaves out, and when the bleeding heart needs protection from the summer sun, the tree will provide it.
Bleeding heart prefers humus-rich, moist soil, with lots of organic matter, but it is not too particular about soil pH. It prefers a slightly acidic soil, but will do fine in neutral soils. Spread a 2- to 3-inch layer of organic matter, such as compost or well-rotted manure, over the existing soil. Work it in to improve aeration and create a loose soil that allows the roots to grow.
Keep plants well watered throughout the summer, especially in warmer weather. Even then, they may disappear until the fall or next spring. If you recently planted your bleeding hearts, it would be wise to mark the spot, so you do not accidentally dig in the area while your plants are dormant. Western bleeding heart is a little more drought-tolerant than the other species, but it is still best to treat them all as woodland plants and provide a moist—but not wet—environment.
Temperature & Humidity
A bleeding heart plant begins to yellow once the summer heat ramps up. This is perfectly normal, as it is a sign that it is storing away energy for the winter. Its ideal temperature is 55 to 75 degrees Fahrenheit. It has a good tolerance for high humidity.
Bleeding heart plants are not heavy feeders, so when to fertilize depends on the quality of your soil. If you have rich, organic soil that is amended every year, you will not have to feed at all. Bleeding hearts are woodland plants and do especially well with a top dressing of leaf mold.
Is Bleeding Heart Toxic?
Bleeding heart plants contain isoquinoline alkaloids that are toxic to humans and animals. Serious cases of poisoning are common in dogs and horses, but much less common in humans.
Symptoms of Poisoning
The toxins in bleeding heart can cause liver damage and seizures in humans when ingested in large quantities. Small dogs are especially likely to suffer liver damage with relatively limited exposure. Horses that graze on the plant have also been known to be poisoned. Humans should not eat any part of the plant and can experience mild skin irritation or rash from contact.
Pruning Bleeding Heart
No pruning or deadheading is required, since this plant will bloom again later in the season. Be sure to leave the flowers if you want it to go to seed. You can trim back the foliage when it starts to turn ugly. Fringed-leaf varieties will eventually get a little ragged looking and can be sheared back to their basal growth; they will re-leaf and rebloom.
Common Pests & Diseases
Bleeding heart is fairly trouble-free, although common garden problems such as aphids and powdery mildew are occasional problems. The leaves are susceptible to leaf spots, and the easiest solution is to shear back the affected foliage. Although bleeding hearts like moist soil, they cannot tolerate heavy, wet soil and may get root rot if left with wet feet too long.
Information courtesy of TheSpruce.com