Perennial Solutions: Dicentra spectabilis ‘Valentine’
One of the most recognized and reliable perennials in shade gardens is the old-fashioned Bleeding Heart. When grown under partial shade in well-drained soils with ample moisture, it is hard to beat the flower power and dependability of Dicentra spectabilis.
For as long as I can remember, there have been only two Dicentra spectabilis varieties on the market: the straight species D. spectabilis with pink and white flowers and the cultivar ‘Alba’ with white flowers. However, an exciting new cultivar, ‘Valentine’, brings a vibrant new look to an old-fashioned favorite. It was discovered as a chance seedling by Phyllis and Lyle Sarrazin of Prince George, British Columbia, Canada and is brought to the market by Pride of Place Plants.
‘Valentine’ provides the old-fashioned look of Bleeding Heart with vibrant red flowers. The upright plant habit is similar to its more familiar counterparts, but is slightly shorter, reaching 30 inches tall by 36 inches wide when the clumps are mature. The foliage has a tinge of purple color to it as it emerges in the spring, then appears deep green as the leaves expand. The clumps produce dozens of arching flower stems with dangling, puffy, heart-shaped, deep, bright-red flowers with white tips in the late spring.
Bleeding Heart is a reliable, long-lived perennial that can be grown throughout a wide geographic area, surviving in USDA Hardiness Zones 3 to 9. After its brilliant floral display in the spring, the plants tend to go dormant during the summer months, particularly if it is hot and dry. In summers with ample moisture and moderate temperatures, the foliage often remains present until the fall. In addition to making a great perennial in shade and woodland garden settings, dicentra ‘Valentine’ makes a great early spring flowering perennial for container programs, a seasonal indoor flowering house plant, and as a delightful addition to fresh floral bouquets.
Dicentra spectabilis ‘Valentine’ is vegetatively propagated by means of basal cuttings and division. However, ‘Valentine’ is a patented variety (USPP22739, COPF) and asexual propagation is prohibited at this time. Propagation is limited to licensed propagators at this time.
Most growers will receive bare root as their starting materials. There are often several grades or sizes available, such as 1-2 eye, 2-3 eye, and 4+ eye. The smaller sizes are ideal for use in small container sizes; conversely, use bare root with more eyes when growing in larger sized pots.
Dicentra performs best in a growing mix with both good water holding characteristics and, more importantly, adequate aeration; many bark-based growing mixes work well. When transplanting, plant the bare root so the crown is slightly below the soil surface. If necessary, the roots can be trimmed to fit into the desired container size without having a negative effect on flowering.
Bleeding Hearts are light to moderate feeders requiring nitrate levels of 100 to 125 ppm under a constant liquid fertilizer program or 250 ppm as needed. Several growers incorporate low rates of controlled-release fertilizers into the growing mix before planting to effectively provide nutrients to containerized dicentra. Maintain the media throughout production with a pH between 5.8 and 6.4.
After planting, water them thoroughly to eliminate air pockets and ensure good contact between the roots and the growing mix. Keep them on the drier side initially, since they will not be able to absorb and use much moisture at this stage, and keeping them dry forces the roots to develop as they seek out moisture and nutrition. As the plants begin to emerge, gradually increase the moisture levels. Once they are established and growing rapidly, dicentra require an average amount of irrigation. They should be kept slightly moist during production to prevent them from going dormant; this is particularly important during the warm summer months.
With its compact habit, it is usually not necessary to control plant height during production. If height control is required, daminozide (B-Nine or Dazide) is effective at reducing elongation. One to two applications of 2,500 ppm should provide adequate height control.
Once they begin to actively grow in the spring, ‘Valentine’, like all Dicentra spectabilis, flushes growth very quickly, easily growing a few inches taller each day. To reduce stem elongation and produce fuller, more attractive plants, it is helpful to apply plant growth regulators early in the production cycle. Foliar spray applications of 2,000- to 2,500-ppm daminozide (B-Nine or Dazide) are effective at controlling plant height. Begin applying spray applications of daminozide when the plants reach 3 inches tall and reapply as needed at seven- to 10-day intervals.
Insects and Diseases
There are several plant pathogens including downy mildew, Fusarium wilt, powdery mildew, rust, Sclerotium and Verticillium wilt that may occasionally be observed infecting fern-leaved Bleeding Hearts. Insects and diseases can be detected with routine crop monitoring; control strategies may not be necessary unless the scouting activities indicate actions should be taken.
Several insect pests including aphids, caterpillars, fungus gnat larva, slugs, spider mites, thrips and whiteflies commonly feed on dicentra. Of these pests, whiteflies and aphids occur the most frequently during production. Although injury from these pests and diseases may occur, more often than not, they can be grown free of problems. Insects and diseases can be detected with routine crop monitoring; control strategies may not be necessary unless the scouting activities indicate actions should be taken.
Temperature and Scheduling
Dicentra ‘Valentine’ blooms very readily after growth resumes after the overwintering period and is a great item for perennial programs in the early spring. Some growers produce Bleeding Hearts as part of a premium program for Valentine’s Day. Growers most commonly force dicentra into bloom using plant materials carried over from the previous growing season, from containers transplanted in the mid fall, or from bare root planted in the winter or early spring.
Dicentra spectabilis has an obligate cold requirement for flowering. They can be vernalized in the final container by providing a minimum of nine weeks at temperatures less than 40° F before forcing them into flower. Late winter and spring planted bareroot does not require additional vernalization as it received appropriate cold treatment before the plants were harvested.
After the cold requirement is achieved, ‘Valentine’ can be grown at natural day lengths, as they are day-neutral plants. The length of the photoperiod does not have any effect on the time to flower or the number of blooms produced. It is best to grow dicentra under cool temperature regimes; 50 to 55° F is ideal. At these temperatures, they will typically bloom in approximately five to six weeks. Planting later in the spring typically finish faster (four to five weeks) than late winter plantings. Dicentra for Valentine’s Day programs should be planted during the first week of the year. The shortest and highest quality plants are achieved when they are grown outside.
Dicentra spectabilis ‘Valentine’ is available as bare root and can be obtained from licensed propagators including Pioneer Gardens (www.pioneergardens.com) and Walters Gardens, Inc. (www.waltersgardens.com).