Bleeding heart is native to the cool, moist woodlands of northeast- ern Asia, growing in dappled shade. It does not bloom well in dense shade and will not tolerate poorly drained soils, especially in the winter. It is adapted to U.S. Department of Agri- Comprehensive culture hardiness zones 2 to 9. Plants can tolerate more sun in the more northern latitudes if kept reliably moist. Partial shade is required in Crop Reports the south or where summer temper- atures are high. High, diffuse light under cool, moist, well-drained con- ditions in a neutral to slightly alkaline soil high in humus are optimal con- Bleeding Heart: A Review for Growers ditions. Plants need to be protected from wind. Plants can form clumps 1 m across and almost as tall. Anec- Laurie Hodges1 dotal reports indicate stems approach- ing 2 m height. If plants are cut back in midsummer, no new leaves will form ADDITIONAL INDEX WORDS. Dicentra spectabilis, Lamprocapnos spectabilis, perennial, cut flower, floriculture, breeding (Hanchek, 1989), whereas cutting flowering stems in the spring will re- SUMMARY. A favorite garden flower for centuries, bleeding heart or old-fashioned sult in new floral racemes developing bleeding heart (Lamprocapnos spectabilis) is also used as a potted plant and in floral from axillary buds on the stem or from arrangements. Most general gardening guides include information on growing crown buds. Once growing, long pho- conditions but provide few specifics regarding plant growth and development that toperiods of 18 h promote growth and are important to those interested in commercial cultivation and use in the floral industry. Although uncommon in the U.S. floral industry, the plant is adaptable for flowering indefinitely, especially when use as a flowering potted plant and as cut floral stems with potential for year-around combined with a periodic cutting back availability. This report provides detailed cultural information for this audience of plants to promote new flushes of with an overview of the history of the species and its unique characteristics. Despite growth (Hanchek, 1989; Weiler and the popularity of the spectacular flower and plant form, until 1997 it was only Lopes, 1977). available in the common pink and white form or a pure white form and exhibited little phenotypic variability. Three new cultivars, Goldheart, Valentine, and History Hordival, are now available with distinctive foliage and flower colors. These new Bleeding heart is native to south- cultivars are poised to create much interest among gardeners and cut flower growers. eastern Siberia, Korea, and the north- The history, culture, propagation, forced flowering, use as a cut flower, pest management, and pharmacological potential are presented. ern areas of China. Grown in Chinese gardens and as a forced potted plant for hundreds of years, it was first seen he old-fashioned bleeding blood. The leaves are coarsely dissected, by Western scientist Linnaeus in 1765 heart (Dicentra spectabilis)from blue-green, with a fern-like appearance. as a drawing in a student thesis. Al- Tnortheast Asia was recently re- The flowering stem and flowers are in though it was mentioned in European classified as Lamprocapnos spectabilis two planes of symmetry making them literature as early as 1804 and was in the family Fumariaceae based on particularly attractive and easy to in- present in England as early as 1812, DNA sequencing and differences in corporate into floral designs. At the these introductions died out before pollen and seed coat anatomy from base of each outer pink petal is a spur, becoming established (Tebbitt et al., other Fumariaceae (Liden et al., 1997). which holds nectar from glands at the 2008). Successful introduction into The former Latin name, Dicentra spec- base of the stamens. Plants flower over European gardens followed its rein- tabilis, translates as ‘‘spectacular two a 3- to 4-week period in late spring, troduction in 1846 by Robert For- spurs,’’ while Lamprocapnos means with anthesis starting between late April tune on his return to England from ‘‘bright smoke,’’ both referring to the and early June through the north tem- a collecting trip to China for the flowers. It is a spectacular flower known perate zones. Royal Horticultural Society. Fortune for at least 2000 years for its beauty and for centuries as a garden plant (Zeiner, 2006). The plant has arching stems Units (racemes) of pink heart-shaped flowers To convert U.S. to SI, To convert SI to U.S., that appear to bleed a drop of white multiply by U.S. unit SI unit multiply by 0.3048 ft m 3.2808 3.7854 gal L 0.2642 Department of Agronomy and Horticulture, 377 2.54 inch(es) cm 0.3937 Plant Sciences Hall, University of Nebraska, Lincoln, 1 ppm mgÁkg–1 1 NE 68583-0724 1 ppm mgÁL–1 1 1Corresponding author. E-mail: [email protected]. ( F – 32) O 1.8 F C(1.8· C) + 32
• August 2012 22(4) 517 COMPREHENSIVE CROP REPORTS purchased the plant from a nursery in increased dry weight, or both plants remain vegetative and may flower Shanghai. It flowered in England in through mid-November (Hanchek, until fall when dormancy is induced by May 1847 (Fortune, 1847). By 1852, 1989). Unlike many dormant buds, a photoperiod of 14 h or less (Tebbitt it had appeared in North America and each lateral bud scale contains both et al., 2008; Weiler and Lopes, 1985). throughout Europe, primarily as a a vegetative and reproductive meri- Native to eastern Siberia, northern forced pot plant in the conservatory. stem. The terminal bud scale contains China, and Korea, bleeding heart It was believed not to be frost tolerant, only foliage meristems (Williams, does not tolerate high temperatures despite Fortune predicting it to be so, 1903). A cold period is not required well; however, temperature does not and crowns were dug from the garden for differentiation of the floral meri- induce dormancy. Plants left to die- after the foliage died down and stem but is required for stem elonga- back naturally in response to short brought inside, where they typically tion in the spring. Gibberellic acid days are larger and have more flower- flowered in February, being returned cannot substitute for the cold period ing stems the following spring. We to the garden in May. By 1878, the (Lopes and Weiler, 1977; Song et al., have cut as many as 25 flowering stems garden adaptability of the plant was 2003; Weiler and Lopes, 1976). per plant from 3-year-old plants started well recognized and it was one of the Crown buds form vegetative as two- to three-eye divisions in 5-gal top six garden plants in England shoots that have solid stems and re- pots when kept moist and left to die- (Coats, 1968). Plants were advertised productive stems that are hollow. The back naturally in the fall (L. Hodges, for sixpence (6d) in 1882 in England sap is watery. Some people have an unpublished data). (Gardening Illustrated, 1882), equiv- allergic reaction to the sap, which is Apparently, a hardening effect takes alent to £13 or U.S. $22 in today’s high in isoquinolines and other alka- place in the field in the fall that affects buying power. The white-flowered loids that make the plant toxic (Israilov dormancy and regrowth in the spring. bleeding heart (L. spectabilis var. alba) et al., 1984; Stern, 1961). When plant- During cold storage, plants dug before was first mentioned in the Proceedings ing crowns, buds should be 2.5 to 5 cm the first week of November developed of the Royal Horticultural Society in below the soil surface. Bleeding heart considerable mold and poor regrowth 1864 noting its blush white color and benefits from excellent nutrition dur- in a Michigan study (Hanchek, 1989; origin from China (Royal Horticultural ing its vegetative period aboveground. Hanchek and Cameron, 1995). Dig- Society, 1864), which is the earliest Only general recommendations for cul- ging crowns in early winter and storing known reference to this color form. ture in the landscape have been re- them at 0 C for 4 months resulted in No information regarding the original ported for bleeding heart (Armitage, higher quality plants that were taller, source, wild or cultivated, of the 2008; Tebbitt et al., 2008). Soil should had more vigorous regrowth, and white-flowered plant is known. Early be well-drained and moderately fertile. were more likely to flower when forced white-flowered clones may have been Well-rotted manure or compost may (Hanchek, 1989). Time from potting different from the plant we know today be added to provide nutrients and to to first flower was most rapid, averag- as the flowers were reported to be improve soil structure. Addition of ing 3 weeks, for plants harvested tinged with pink and the plants much phosphorous in the form of bonemeal later in the fall and stored for 4 months weaker than the red-flowered clones or wood ashes from deciduous hard- (Hanchek, 1989) although others re- (Tebbitt et al., 2008; Williams, 1903). wood trees is recommended by Tebbitt port good growth after 8 to 12 weeks Although commonly grown in gardens et al. (2008). Typical of many geo- of storage at 5 C (Lopes and Weiler, worldwide, bleeding heart recently was phytes, nutrients likely are translocated 1977). If a cold storage facility is not included in a proposed list of threat- from senescing foliage to the crown available, potted plants can be over- ened crop plants because of its potential and tuberous storage roots, which con- wintered outside. In a northern cli- uses in pharmacology and the relative- tinue to accumulate nutrients as long as mate, use of a laminated polyethylene ly few endemic populations known the fibrous roots remain functional. foam blanket provided excellent pro- within its historic range (Hammer and Roots continue to grow for several tection of potted fringed or fernleaf Khoshbakht, 2005). months after the tops have died back bleeding heart (Dicentra exima)and as long as the soil maintains warmth doubled survival compared with no Plant growth and development and moderate moisture. Thus, plants cover (Fisher, 2001). Similar results Bleeding heart has a spreading, benefit from an annual top dressing could be expected with bleeding heart. tuberous root system which over- in the fall or early spring with com- Where winter temperatures fall below winters. These large, cylindrical roots post or aged manure as long as there –10 F or where there are high winds, consist largely of starch-filled paren- is good drainage. Poor drainage, espe- the recommendation is to use a double chyma cells, which provide nutrients cially in winter, will kill the plant. For layer of foam frost blanket or place for spring growth. During the grow- pot culture, a general recommenda- the potted plants inside an unheated ing season, a mass of fibrous roots also tion would be a complete fertilizer rate greenhouse or high tunnel under develops from the crown (Ignatyeva, of 200 to 250 ppm for both nitrogen a single or double layer of foam frost 2000; Stern, 1961; Williams, 1903). and potassium on a constant feed pro- blanket (Fisher, 2001). Crown buds are formed in late sum- gram (Nau, 1996). mer on the tuberous roots at the base Many authors mention a summer Forced flowering of the previous year’s growth. In a restingperiodwhenthestemsdie- After the appropriate cold pe- Michigan study, crown buds devel- back. This is a response to moisture riod, bleeding hearts can be forced oped rapidly between 11 and 26 stress rather than a heat- or daylength- easily for cut flowers or grown as Sept., followed by bud maturation induced dormancy. If adequate soil potted plants. The ideal temperature evidenced by bud elongation, moisture is maintained consistently, for forcing is 10 to 12 C. If warmer,
518 • August 2012 22(4) stem quality suffers (Lopes and Weiler, plant size, color, and inflorescence Propagation 1977). The expansion of the flowers (Kim et al., 1999). Immature flowers Plants do not self-pollinate and and the number of flowers per raceme that develop on cut stems after har- require pollination by a different clone are greater with supplemental lighting vest or as flowers mature on potted to set seed. When conditions in the (Lopes and Weiler, 1977). Although plants often are lighter in color and garden are appropriately cool and often considered a shade plant, higher the color of open flowers will fade moist with humus-rich soil and plants light intensities result in greater root before senescence. If potted plants are of different clones are in close proxim- growth and earlier flowering than treated with additional light, or cut ity, self-seeded plants may be consid- low light intensities, which, when flowering stems are treated before ered a nuisance. Pollination is primarily sufficiently low, may result in flower harvest with silver thiosulfate (STS), by bumblebees (Bombus sp.) seeking abortion (Lopes and Weiler, 1977; plant height/stem length increases nectar and a few other pollinators Mallberg, 2004; Weiler and Lopes, slightly, more flowers open, and color with a long proboscis (Ignatyeva, 1976). Forcing bleeding hearts has retention is improved (Roberts et al., 2000; Stern, 1961). Seeds mature been practiced since they were first 1995). Fading of flowers is less no- in midsummer and are dispersed by introduced and was practiced in Asia ticeable for the white form compared ants (Formicidae) attracted to small before introduction to Europe. Live with the red (Mallberg, 2004). structures on the seeds called elaio- plants in England first flowered in Cut flower somes containing fats (Fig. 1). The May 1847 as forced potted plants ants gather the seeds and bring them (Fortune, 1847). It never caught on The graceful form of bleeding back to their nests to consume the inAmericaasmuchasinEngland, heart has been admired as a cut flower elaiosome thereby dispersing the seeds even as late as 1928 (Bailey, 1928). for centuries. Plants in the garden locally. This restricted distribution Garden plants are dug in late Octo- normally flower for 4 weeks starting likely contributed to the evolution- ber,dividedsothateachdivisionhas as early as late April to June, key ary isolation and speciation within several eyes, roots trimmed as needed months in the U.S. floral business. the family. Seeds generally are fertile to fit into pots, and the potted plants Bleeding heart stems can be cut when and require a warm period followed kept in cold storage or buried in the the first heart is fully open although by a cold and moist stratification soil outside. In early January, pots are often those cut by growers for local followed by second warm period for moved inside to a sunny window sill or markets or those harvested for per- maturation and germination. Seeds cool greenhouse. It is more common sonal use are not harvested until three now to start with either two- to three- or more flowers are fully open. It is eye or three- to five-eye divisions from desirable to have at least five flowers Table 1. Best conditions for bleeding the cold storage of a wholesale sup- on a stem; seven to 12 is common. heart flowering and stem length. plier. When potting divisions, up to Marketable stems from first year 50% of the root mass can be pruned two- to three-eye crowns from cold Cool, moist root zone during initial away without significantly affecting storage averaged 35 cm long from growth; 13 C (55.4 F) is ideal subsequent growth or flowering (Weiler the cut stem to the first open flower Well-drained, moist soil with humus and Kirk, 1984). Maintaining moder- (Mallberg, 2004). When harvested and high organic matter content ately moist soil is most important be- with one flower on the raceme fully High, diffuse light for more flowers cause of the rapid growth of the plant, open, the other flowers will develop per stem which will normally flower within 1 normally when stems are placed in Wind protection month. Under controlled conditions, a commercial floral preservative. The 16 to 18 h of light for longer stems plants flower 3 to 4 weeks after plant- white-flowered form does not have 15 to 20 weeks of chilling at 5 C ing at 11 C night temperature and 2 quite the same arching raceme as the (41.0 F) or colder to break dormancy to 3 weeks after planting at a 15 C red-flowered form, tending to be ei- and promote stem elongation night temperature (Weiler and Lopes, ther more vertical or horizontal than Avoid drought or waterlogged soil 1985). The shoots are cut off after the pure arch of the red cultivar. Allow stems to dieback naturally in the flowering and the plant moved to Bleeding hearts are recognized as fall when daylight is less than 14 h a cool spot until spring when it can ethylene sensitive (Stevens, 1998), be planted outside. New growth and STS treatment prolongs vase life often will include some flowering (Roberts et al., 1995). Our research stems. found that floral preservatives extended Forcing crowns for sale as potted the average vase life for red-flowered plants has been the subject of several bleeding heart from 8 to 12 d and research projects. For container pro- from 8 to 17 d for the white-flowered duction, a short, compact plant is form, compared with vase life in water desired. Plants are stocky when grown (Mallberg, 2004). Vase life of the red at short photoperiods of 14 to 15 h of bleeding heart stems stored at 2 Cin light. Plant growth regulators must floral preservative gradually decreased be applied immediately after shoot from an average of 7 d after 16 d of growth is initiated and again 5 d later storage to 4 d when kept in cold because of uneven shoot emergence. storage for 25 d (Mallberg, 2004). Daminozide at 3000 ppm or paclo- Best conditions for flowering and stem Fig. 1. Seeds of bleeding heart with butrazol at 50 ppm provided the best length are summarized in Table 1. white elaiosomes.
• August 2012 22(4) 519 COMPREHENSIVE CROP REPORTS freshly harvested in late spring can be volume) in crates lined with polyeth- inevitably to plant decline and death germinated by sowing into a flat con- ylene plastic in a cooler maintained (Lockhart, 2000). Symptoms often are taining a peat-based lightweight ger- between 1 and 4 C (Cameron and evident only under cool conditions. It mination mix and placing the flat Maqbool, 1986). is transmitted via the root nematodes, into a coldframe, keeping the mix- Tissue culture techniques were Paratrichodorus and Trichodorus.Since ture slightly moist. Germination will publishedin1982(Lazarzetal., many herbaceous perennials are prop- occur the following spring. Alterna- 1982). Tissue culture is not used com- agated by division, the incidence of tively, cold stratify the seeds in the mercially to propagate bleeding heart diseased plant material is increasing moist media for 6 to 8 weeks at 4 C, because of the ease of crown division and it is increasingly common in pur- then move the seedling tray to a place and rooting cuttings. chased crowns (Lockhart, 2000). with light and cool temperatures (15 Possible causes of various prob- to 18 C) for another 2 to 4 weeks. Pest management lems observed on bleeding heart Repeated stratification may result in Bleeding hearts have few pest plants are in Table 2. germination of additional dormant problems. Thrips (Thripidae) may Weeds may be a problem in larger seeds. Once seeds have germinated, damage flowers and occasionally white- field production systems or landscape the young plants can be divided flies (Aleyrodidae) will be a problem in plantings. Crown buds are close to the carefully in the spring or after the a greenhouse crop, but few other in- soil surface and root damage will leaves have died down. Gibberellic sects affect the plant. Slugs and snails shorten the life of the plant so it is best acid (25–100 ppm GA3 or GA4+7) (Gastropoda) may eat new growth. to avoid cultivation. Generally, few can increase the percent germination Bleeding hearts are not bothered by broadleaf weeds develop in the shade (Kim and Chung, 2001; Kim and Um, rabbits (Leporidae) or deer (Cervidae). under bleeding heart plants. The few 1995), which is rarely more than 60% Fusarium wilt (Fusarium sp.), viruses, reports located on chemical weed con- and often erratic (Nau, 1996). Seed- and fungal leaf spots (Stemphyllium) trol indicate that bleeding heart is tol- lings will first flower during their can occur. A phytoplasma infection can erant of oxadiazon, oryzalin, trifluralin, second year (Nau, 1996). result in a proliferation of shoots or napropamide, and dacthal. It does not Plants can be pinched and termi- witches broom effect. It is also suscep- tolerate diuron or simazine (Bateman, nal vegetative cuttings rooted in a 1 tible to southern blight (Sclerotium 1971; Didario, 1961; Schuett and peat:1 perlite mix (by volume) al- rolfsii). Occurrence of gray mold (Bo- Klett, 1989; Tichknor, 1960). though propagation by root division trytis cinerea) can be a problem during is more common. Year-around cul- storage of the cut stems, which can be Breeding and selection ture of bleeding heart is feasible reduced with good air circulation. Of Old-fashioned bleeding heart is through production of stock plants disease pathogens, viruses are most now recognized as evolutionarily dis- using rooted cuttings with both the commonly seen. Plants can be infected tinct from all other types of bleeding propagation and growth of the plants with tobacco rattle tobravirus, tobacco hearts including those in the genus in long photoperiods. Vegetative cut- ringspot nepovirus, tobacco mosaic Dicentra such as dutchman’s breeches tings root best when taken in the virus, ribgrass mosaic virus, and the (D. cucullaria) or fernleaf bleeding spring from young growth and placed aster yellows phytoplasma (Gill et al., heart, also known as pacific bleeding in moist perlite or vermiculite in a 2006; Lane, 2006; L. Lane, personal heart (D. formosa). It does not cross humidatmosphereorundermist.It communication). with any other genus in the Fumar- may take a month for roots to form. Tobacco rattle virus is the most iaceae family (Stern and Ownbey, Rooting hormone is not necessary. devastating of the various viruses that 1971; Tebbitt et al., 2008). Thus, Root cuttings can be made from infect bleeding heart. First found in the white-flowered form discussed tuberous roots in the spring or fall by bleeding heart in the United States in above is apparently a rare natural taking a 7.5- to 10-cm section of a root 2000, it is a systemic virus, leading mutant discovered before 1846, and inserting it into a moist peat:per- lite mixture (Armitage, 2008). Crown divisions are normally made in the fall but also can be made in very early Table 2. Production problems affecting bleeding heart and possible causes. spring before budbreak. Most bleed- Problem Possible cause ing hearts in the trade now are repro- duced vegetatively by dividing the Flower abortion, few flowers Too warm; insufficient chilling; too much shade crown into two- to three-eye or three- per stem to five-eye divisions. To store divisions Flowers on very short stems or Insufficient chilling time or temperatures; (crowns) over the winter, it is impor- flowers without stem elongation high temperatures during stem elongation tant that they do not dry out; however, Plant dies back soon after flowering Drought; too much shade bleeding heart is very susceptible to Plant fails to emerge in spring Tobacco rattle mosaic virus; crown decay mold during storage, especially if due to excess moisture harvested before full dormancy in the Dark, mushy stems at soil line Bacterial rot due to poor drainage; waterlogged fall (Hanchek, 1989; Maqbool and soil overwinter; white mold (Sclerotinium Cameron, 1994). From crowns har- rolfsii) if white threads of mold present vested in November, the best method with small, hard, round pellets (sclerotia) found was to pack the crowns in Mosaic, circles, or other patterns One or more viruses slightly moist 1 peat:1 perlite mix (by on the foliage; crinkled foliage
520 • August 2012 22(4) perhaps with subsequent selection for rights (Flowerweb, 2010; Verschoor, Bailey, L.H. 1928. The standard cyclope- pure white color and improved vigor. n.d.). In 2011, the Sarrazins filed dia of horticulture. Vol 1. MacMillan, It sets viable seeds. There are reports a patent application for another bleed- New York. by several authors of a white cultivar ing heart seedling discovered in 2005 Bateman, G. 1971. Herbicides on herba- called Pantaloons, but no original with orange-red flowers, which is nam- ceous plants. Gardeners Chronicle 169: citation or source of this cultivar ed ‘Hordival’ (Sarrazin and Sarrazin, 24–26. has been located and it may be either 2011). It also is slightly shorter and Cameron, A.C. and M. Maqbool. 1986. a trade name or common name more compact than the wild species. It Postharvest storage of bare-root hardy (Paghat, n.d.). The cultivar Gold- also has dark red stems. Since a natural perennials: The relation of water loss to heart became available in 1997. hybrid is not possible and variation is storage survival. Acta Hort. 181:323–329. ‘Goldheart’ has broad, bright yellow- very limited in this old species, tradi- gold leaves in the spring on peach- tional breeding of new cultivars has Coats, A.M. 1968. Flowers and their colored stems. The gold color of the been slow. In Korea, techniques were histories. A&C. Black, London. leaves is most intense when grown in recently developed using somatic re- Didario, A. 1961. Evaluation of dacthal in moderate shade and may have merit generation with the intent to develop ornamentals. Proc. 14th Southern Weed as cut foliage. By midsummer, the new commercial cultivars of this flower Conf. p. 158–163. leaves are lime green. It is a strong through genetic transformation (Lee Fisher, P. 2001. Overwintering perennials grower, performing best in moist soil and Lee, 2003). in containers. 7 Sept. 2010.
• August 2012 22(4) 521 COMPREHENSIVE CROP REPORTS
Kim, H. and J. Chung. 2001. Effects of Mallberg, I.L. 2004. Forcing Dicentra spec- Stern, K.R. 1961. Revision of Dicentra GA3, moist-chilling storage and removal tabilis (L.) Lem. as a specialty cut flower. (Fumariaceae). Brittonia 13:1–57. of funiculus on the germination of Univ. of Nebraska, Lincoln, MS Thesis. Dicentra spectabilis. Korean J. Hort. Sci. Stern, K.R. and M. Ownbey. 1971. Hy- Technol. 19:78–80. Maqbool, M. and A.C. Cameron. 1994. bridization and cytotaxonomy of Dicen- Regrowth performance of field-grown tra. Amer. J. Bot. 58:861–866. Kim, S., A.A. DeHertogh, and P.V. Nelson. herbaceous perennials following bare- 1999. Effects of plant growth regulators root storage between –10 and +5C. Stevens, A.B. 1998. Field grown cut applied as sprays or media drenches on HortScience 29:1039–1041. flowers: A practical guide and sourcebook. forcing of Dutch-grown bleeding heart as 2nd ed. Avatar’s World, Edgerton, WI. McNulty, J., J. Poloczek, V. Larichev, a flowering potted plant. HortTechnology Tebbitt, M., M. Liden, and H. Zetterlund. 9:629–633. N.H. Werstiuk, C. Griffin, and S. Pandey. 2007. Discovery of the apoptosis-inducing 2008. Bleeding hearts, corydalis, and their Lane, L. 2006. TRV symptoms on Dicentra activity and high accumulation of the bute- relatives. Brooklyn Botanic Garden/Timber spectabilis. 22 Aug. 2007.
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