South African Foxglove, an easy exotic annual (Ceratotheca triloba)
(Editor's Note: This article was originally published on July 21, 2010. Your comments are welcome, but please be aware that authors of previously published articles may not be able to respond to your questions.)
Foxgloves are perennial, rosette-forming, spring blooming cottage garden favorites, right? Not this one. South African Foxglove, Ceratotheca triloba, is a lovely, statuesque, easy care flowering annual. As its name states, it is native to a large southern portion of the African continent (not just the Republic of South Africa.) It is somewhat rare in the mainstream marketplace but seems to have a small fan club in Dave's Garden and is sold by several specialty vendors.
When our fearless editor suggested an article about South African Foxglove, I volunteered. I had two plants growing in my very own garden. While that didn't make me an instant expert, it at least made for painless photo submission and gave me firsthand knowledge. I soon wondered if I'd bitten off more than I could chew. None of my gardening books had a word to say about the genus Ceratotheca. Even the ten pound botanical behemoth The Plant Book (An Encyclopedia of Worldwide Flora, 3800 Species in 2100 genera) overlooked the genus Ceratotheca. Fortunately, just a little web surfing landed me on a beach of foxglove facts and triloba trivia.
South African foxgloves, or wild foxglove (although Digitalis foxgloves were originally wild too, right?) was known to botanists by 1888 when it was illiustrated for Curtis's Botanical Magazine. Where it originates, this foxglove has been used in traditional African medicine and as a leafy green vegetable. Other, more whimsical names for the plant are "poppy sue" or "vingerhoedblom." I find "finger hood bloom" more accurate a descriptive than "fox glove." Contemporary gardeners cultivate wild foxglove for the flowers. The blooms are tube shaped like those of Digitalis. Over an inch long, these flowers can easily hide a bumblee. They hang down on tall stems and open in pairs from early summer through fall. The wild species blooms in a pale lavendar with purple pinstripes down the long lower lip. A white flowering cultivar is available too.
Gardening with South African Foxglove, Ceratotheca triloba
Annual, may overwinter above zone 8, sun to part sun. Good soil and ample water during summer give the best display, may self sow
Foliage: Coarse texture, rounded lobed leaves on bold bushy plant three to five feet, with flower spikes rising above. Soft, fuzzy, odorous leaves said to be deer resistant.
Flowers: Soft lavender with purple pinstripes, or white, foxglove shaped. Blooms open a few at a time per stem, plant several plants close together and pinch to encourge branching
Easy to start from seed, no special treatment needed, transplants not commonly sold. Sow seed indoors eight weeks before last frost, covering lightly.
Contrasts with ornamental grasses, or flowering plants with fine texture or straplike leaves, or purple foliage. Use in the back of the border or as a bold accent, not for containers.
Collect seed by letting pods dry on plant until they split open, then pour seeds out.
PlantScout sources for seeds http://davesgarden.com/products/ps/go/897/
I'm growing the lavender flowered foxglove pictured above, thanks to Dave's Garden pal Gitagal. Gita is a generous plant lover who frequents the Mid Atlantic Gardening forum. She grew South African Foxgloves from seed last year, not even knowing exactly what it was. Her innate curiosity and love of plants led her to coddle the unknown seedlings until they flowered. Gita's photo posted at Dave's Garden Plant and Tree Identification Forum was promptly and correctly identified for her. Gitagal proudly told her Mid-Atlantic buddies about her "discovery." Then in fall she carefully gathered pods form the plant and broke open the capsules to reveal (and save) the seeds. Here is her picture of the pods and seeds.
Gita shared her seeds with me and I planted them under fluorescent lights this March. The tiny seedlings had me puzzled at first. I discovered that the leaves are not "trilobed" on the very young plants. Once moved to my garden, the foxgloves grew quickly and developed their distinctive lobed leaves. Though they didn't seem overly stressed, I kept them watered through our unprecedented early summer heat wave. The first blooms opened in June. My two plants are now blossoming on eight stems, with more side branches developing day by day. They add an interesting texture, reliable blooms, and unique flower shape to my mostly-perennial beds.
My first year with South African foxglove has been a pleasant experiment. Next year I plan to grow more of them and make a group planting of about seven plants near the back of my flowerbed. Thanks again, Gitagal, for introducing me to this unique annual flower!
To the right, lobed leaves with a flower stem beginning to form
- cerato- horned
- theka- capsule or cup
- tri- three
- loba- sections
- Ceratotheca triloba- plant with horned seed capsules and leaves having three lobes
Seed picture provided by and property of Gitagal- Thanks!!
All other photos taken by and property of author.