Monday Oct 02, 2023

On Gardening: South African geophytes

Today’s column, following our recent overview of South African succulent plants, presents South African geophytes, another large category of plants in this botanical hot spot.

For review, geophytes are perennial plants with an underground food storage organ, e.g., a bulb, tuber, corm, or rhizome. Succulent plant specialists do not regard geophytes as succulents because succulents store moisture while geophytes store food.

An exceptional book, “The Color Encyclopedia of Cape Bulbs” (Timber Press, 2002) lists 83 genera of these plants, which include some 1,200 species, three-quarters of which are endemic to South Africa.

This column features a small sample of these plants growing in my garden, as examples of the large and diverse South African geophytes.

We include two arbitrary groupings of these plants: my sense of the more and less familiar varieties. You might group them differently.

As a heads-up note, several of these plants include “Lily” in their common names but are actually not members of the Lily plant family (Liliaceae). Such misnomers could be based on their resemblance to the familiar form of blossoms of true lilies.

Familiar South African geophytes

African Lily (Agapanthus praecox ssp orientalis Getty White’). This South African plant is a member of the Amaryllis plant family. Its common names include Lily of the Nile, even though it is not native to the River Nile region. The genus includes seven species, including the familiar A. africanus with purple-red blossoms, and the less common A. praecox, which is featured here. The foliage grows from rhizomes to 2 feet tall by 4 feet wide; the flower stalks rise in the summer to 4-feet high. These plants are easy to grow in sun or shade and are often seen in private gardens and community spaces.

Montbretia (Crocosmia ‘Lucifer’). This plant is a widely grown plant among more than 400 hybrid cultivars. They develop from small corms and, in the summer, produce racemes of flame-red flowers. Its small corms are easily separated, making them easy to propagate and potentially invasive, although they have an attractive appearance. They are member of the Iris plant family.

Fortnight Lily (Dietes iridioides). Another member of the Iris plant family, this plant grows from rhizomes to develop 2-4 ft. high clumps of narrow, sword-shaped, stiff evergreen leaves, and numerous white blossoms marked with yellow and violet. The blossoms appear over a long season in two-week intervals (hence the common name), but last for only a day.

Flowering Grass (Freesia laxa var. alba). Known for its powerful sweet scent, this creamy-white flowering hybrid is widely popular in gardens. Other cultivars are available a range of colors, with both mixed and single-color varieties. They grow easily from corms, develop stems up to 18 inches tall, and, in the spring, produce 2-inch long, tubular flowers.

Red-hot Poker (Kniphofia ‘Pineapple Popsicle’). Although there are over 73 species of this genus, almost all plants grown in residential gardens are hybrids of two or more species. They grow from rhizomes and develop clumps of narrow, grass-like leaves ranging from 18-inch dwarfs to 6-ft. giants. They produce tall spikes of upright, brightly colored flowers in shade of red, orange, or yellow, often bi-colored. Members of the Lily plant family, they have a long blooming season, mostly starting in the summer. They grow in full sun or partial shade, depending on the variety, but all require moderate moisture.

Calla (Zantedeschia aethiopica). Sometimes called “Calla Lily,” this plant is a member of the Arum plant family (Araceae). They grow from rhizomes, can rise to 3 feet tall, and need year-round moisture to produce their attractive white bracts (or spathes) that surround a spike (or spadix) of tiny true flowers. Hybrid cultivars are available in a wide range of spathe colors.

Less familiar South African geophytes

Blue Sceptre (Aristea capitata). This plant, a member of the Iris plant family, grows from rhizomes to form linear leaves in clumps 3-ft. tall and wide, with taller stalks of true-blue flowers with yellow stamens. The more common variety, A. ecklonii ‘Blue Stars’, is very similar.

Snake Flower (Bulbine Frutescens). This plant has bulb-shaped tubers (not really bulbs), from which grow a 2-ft. clumps of succulent leaves and, in the spring, 2-3 foot spikes of small yellow flowers. They are members of the Asphodelaceae plant family and related to Haworthias and Aloes. They grow readily and can be propagated easily from stem cuttings. I acquired a handful of cuttings from a recent garden exchange, and I need to get them in the ground.

Bush Lily (Clivia miniata). Yet another member of the Amaryllis family. These have been very popular plants in California since shortly after they arrived in England from South Africa. The commonly griownb C. miniata has orange-red or yellow blossoms and (rarely) nearly white flowers that are natural mutations. They have attractive dark green, strap-shaped leaves. Several hybrid cultivars have been produced through various combinations of the four species of the genus.

Natal Lily (Crinum moorei). Another Amaryllis plant family member, the Natal Lily develops bulbs that can be 8-inches in diameter, a flowering stalk up to 4 feet tall, and clusters of five to 10 large, open, white to pale pink flowers. In nature, it grows in damp, marshy areas, but it thrives with minimal irrigation in my garden. A recent online interview with Jenks Farmer, the author of “Crinum: Unearthing the History and Cultivation of the World’s Biggest Bulb,” described this plant as a favorite of gardens in the southeastern United States, but it also grows well in the Monterey Bay area.

Blood Lily/Paintbrush Lily (Haemanthus coccineus). There are 22 species within this genus, a member of the Amaryllis plant family. H. coccineus, among the earliest species identified, has blood-red blossoms, hence the common name; several other species have white flowers. The plant has paintbrush-shaped blossoms, which appear in late summer, followed by strikingly attractive broad leaves.

Guernsey Lily (Nerine sarniensis). Another Amaryllis plant family member, the Guernsey Lily is a summer-dormant, winter-growing species that develops clusters of funnel-shaped flowers with recurved petals, in colors ranging from crimson to scarlet, and from pale pink to deep rose-pink. There is also an attractive pure white form. The plant has clusters of strap-shaped, linear leaves that follow the flowers.

Advance your knowledge

The Wave Hill Public Garden & Cultural Center, located in Bronx, New York, has announced a new series of webinars, beginning with “New Aesthetics for Public Spaces,” at 3 p.m. on Jan.19. The presenter will be garden designer and landscape architect Ching-Fang Chen, described as “passionate about deepening the connections between people and the environment.” In her presentation, she will “share how she fuses cultural and ecological values into design to deliver a more essential expression of beauty.” For more information and to register for this fee-based event, browse to and scroll to the title of the webinar.

Enrich your gardening days

Explore the botanical riches of South Africa, particularly the succulent plants described in a recent column and the geophytes sampled in today’s column. As already noted, some South African geophytes are widely grown in California gardens, but other less common varieties offer unusual attractive forms and a welcome change of pace compared to everyday garden nursery offerings. They are well-suited to the Monterey Bay area’s growing conditions, so they won’t require exceptional cultivation skills.

Enjoy your garden and include a bit of exploration!

Tom Karwin is past president of Friends of the UC Santa Cruz Arboretum, Monterey Bay Area Cactus & Succulent Society, and Monterey Bay Iris Society, and a Lifetime UC Master Gardener.

On Gardening: South African geophytes

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