Bleeding Heart Vine

Family: Verbenaceae (Verbena family)
Genus: Clerodendrum
Species: thomsoniae

[Regular readers will not be surprised to learn that taxonomic and nomenclature issues may affect your ability to learn more about this plant. Instead of Verbenaceae, you might find it included in the Labiatae or mint family, which is sometimes named Lamiaceae; and there might be a “p” included in its species name, turning thomsoniae into thompsoniae. There are reliable sources on each side of these possibilities and as I write this I haven’t received an authoritative response to my inquiries. So I’m sticking with Verbenaceae and thomsoniae. My money’s on the plant’s namesake being Scottish naturalist Joseph Thomson.]

It’s not often I write in this column about plants that are unsuited to growing outdoors in the Pacific Northwest. It follows I don’t write much about houseplants. I once heard Craig MacConnell describe them as “long-term perishables” and I tend to agree, even though for almost 14 years I’ve fussed over a particular Norfolk Island pine. It’s not a Pinus at all, of course, but an Araucaria heterophylla--and it’s certainly not native to these parts. It demands more care than most plants in my yard, but I’m quite fond of it just the same. So we all have our soft spots. And if we’re about to indulge them, we could do worse than presenting our sweetheart with a nice houseplant for Valentine’s Day. Most last longer and cost less than a dozen red roses. One that stole my heart the first time I spotted it more than 25 years ago is Clerodendrum thomsoniae, sometimes called bleeding heart vine or glorybower. It is indeed glorious.

Do not confuse this bleeding heart vine with any members of the genus Dicentra commonly called “bleeding heart.” These--including those delicate, spring-blooming woodland plants that grow so well here--are native to North America and eastern Asia. C. thomsoniae is a heat-loving plant, native to West Africa, and can be grown successfully outdoors in only a few areas of the southern United States. But it makes a fine houseplant anywhere. In the wild it is a vine that can grow to 12 feet. In captivation--your living room, say, or your kitchen--it’s likely to stay under three feet. So C. thomsoniae makes a large houseplant. It shows to best effect when it’s in a hanging container or at least placed on a high shelf. When properly sited and cared for, it will be full with lush foliage and branches that spill over the edge of whatever container you choose. Its bark is a pretty reddish brown. Its nicely shaped and patterned leaves are large, close set, and a beautiful deep, dark green. They’re really quite attractive, all on their own. But what really sets C. thomsoniae apart from typical houseplants are its masses of stunning red and white blossoms. Calyces of the purest white imaginable shelter blooms--sometimes called corollae--of pure red for a most striking effect.

Purchase a C. thomsoniae commercially or grow yours from a small start shared by a friend. Use fresh, sterile potting soil to avoid passing along any fungal diseases, including botrytis, to which this plant is known to be vulnerable. Of course, using fresh potting soil is always recommended when growing plants in containers. Water the plant when the soil surface feels dry and feed it every two weeks with a complete, balanced, water-soluble fertilizer--except when the plant is taking its winter’s rest from Thanksgiving to--you guessed it--Valentine’s Day. Water sparingly then and don’t fertilize at all. Move your plant to a place where the temperature won’t exceed 65 degrees during the day or drop below 50 at night. Expect some leaf drop as the plant protests change before it adjusts.

Prune your C. thomsoniae in mid-February just before new growth emerges. You’ll want to remove old, overcrowded shoots, particularly any that are too long for your taste. Plus, those flowers grow on new wood. So don’t be afraid to cut the plant back severely. Then place it for the growing season where it will get bright but indirect light and enjoy the typical indoor temperatures of the Pacific Northwest. A bit of humidity will keep the leaves fresh so let it live away from direct sources of heat. You’ll enjoy the heaviest flower crop from early spring through mid-summer and then it will slow a bit into the fall.

Good air circulation, appropriate watering, regular feeding while growing plus proper drainage--these will help your bleeding heart vine thrive. Keep it healthy: when your friends see it, they’ll want stem cuttings to start their own Valentine’s Day surprise for next year.

Iimage used by permission of PlantFiles at davesgarden.com