How to grow Clerodendrum or Bleeding heart vine in your pot and garden
Bleeding heart vine or Clerodendrum is a twining evergreen from tropical west Africa with some confusion about its identity. Other common names include glory bower, bag flower, bleeding glory bower, tropical bleeding heart, and glory tree. Scientifically it is Clerodendrum thomsoniae but is sometimes spelled as C. thompsoniae even in very reputable publications.
Bleeding heart vine, Clerodendrum thomsoniae, is a climbing plant native to tropical West Africa. It has dark green leaves, striking white and red heart-shaped flowers, and black fruits.
According to the International Plant Names Index, this species is in the mint family (Lamiaceae) but some other references, such as the USDA Plants Database, place it in the verbena family (Verbenaceae). It was traditionally placed in that family, but despite being reassigned to the Lamiaceae, not everyone has adopted that change. One thing that is certain is that it is not related to the common bleeding heart (Dicentra spectabilis). The common name comes from the flowers which look like a drop of red blood exuding from the heart-shaped calyx.
Regardless of its true identity, this is a spectacular plant when in flower. The small, slightly flat flowers have inflated, balloon-like white calyxes from which emerge brilliant crimson or dark red corollas with prominent stamens and style (the elongated part of the pistil) that extend way beyond the petals. The flowers are borne in terminal clusters (cymes) of 8-20 together. The flowers last several months, although the red corolla is short-lived. As they age, the flowers turn from white to pale pink or lavender, then eventually become tan as they dry up. It will bloom most of the year given sufficient light and warmth but is most prolific in summer. If pollinated, the flowers will produce fruits. The green fruits ripen to a red to black color before splitting open to reveal four black seeds against a fleshy, bright orange interior.
Even though it is vine or liana, it is also a somewhat bushy climber. The glossy, dark green, oval leaves are 5-7″ long with smooth edges and pointed on the end. In its native habitat, it can grow 10-15 feet tall, but as a container plant will remain much smaller. Provide some type of support, such as a trellis, if you want to let it ramble as a vine. It can also be kept pruned or pinched back into a shrub-like form (or be left to mound upon itself). It works well in a hanging basket. It is a vigorous grower when provided with sufficient water and fertilizer.
This plant needs direct sun in order to bloom well; a sunny window may be sufficient if you don’t move the container outdoors for the season. Water and fertilize regularly when actively growing. Use a rich but well-drained potting medium and keep moist but not wet. Since Clerodendrum blooms on new growth, it is best to cut the plant back after blooming. Thin out old overcrowded shoots and any other far-reaching growth to keep the vine in bounds – don’t be afraid to prune severely. Bleeding heart vine has few pests but mealybugs and spider mites can occasionally be problems.
Although it is root hardy to zone 9, it really is a tropical plant and does need protection from freezing. If grown outdoors, move inside when temperatures fall below 45ºF. When temperatures are cool enough (even indoors), the plant will shed its leaves. New leaves will resprout from the roots or what looks like dead wood in spring. If it does go dormant in the winter, withhold water until the new growth starts (water just enough to keep the soil from drying out and don’t fertilize).
Bleeding heart vine is easy to propagate by cuttings or serpentine layering. Semi-ripe tip cuttings taken in late spring or late summer can be rooted in water or moist sand or another medium. Roots should appear in about 2 weeks. Seeds can also be planted in spring.
There are only a few cultivars of this species. The variety ‘Delectum’ has very large clusters of flowers of a lighter shade of red. A variegated form (‘Variegata’) has cream margins on the leaves.