On the Dry Side: South Africa offers treasure trove of winter-growing bulbs

 South Africa has an extraordinary number of plant species found nowhere else, including hundreds of species of bulbs. Some of these bulbs are well-established in the gardening world, such as Agapanthus or Amaryllis belladonna, but others are little known except to bulb aficionados. They vary greatly in size — from large ones, with bulbs as big as a football, down to miniatures, with bulbs smaller than a pea.

While some grow and flower during the summer months, others spring to life toward the end of the year and grow through the winter. The winter growers come from the western part of the country, which has a Mediterranean climate much like that of California. With very little rainfall during the summer months, these plants respond by sleeping through the dry summers and waking up when the rainy season begins in autumn.

Often, they are so strongly adapted to this regimen that they do not last long when grown in places with wet summers. Happily for us, they present little difficulty in the coastal parts of California, where winters are not too cold and the rainfall arrives just when they need it.

Among South Africa’s treasure trove of winter-growing bulbs is the large genus Lachenalia, with 133 species. These are small plants with delightful flowers, the great majority of them found in the southwest corner of the country, in the winter-rainfall zone. Many of them have spires of tiny short-tubular flowers, but some of the showiest kinds have larger, vividly colored long-tubular flowers, which are pollinated by nectar-feeding birds.

One such species is Lachenalia punctata, which grows mostly in sandy coastal locations both north and south of Cape Town, though there are a few places where it occurs farther inland. This plant has long been known by the name Lachenalia rubida, but recent research shows that the older name, Lachenalia punctata, refers to the same species, and should be used because it was published first, in 1788.

Lachenalia punctata emerges from its summer dormancy in the fall, coming up about late October to November at the Ruth Bancroft Garden in Walnut Creek. The flowers develop rapidly, beginning to bloom even before the leaves have developed fully. Each mature bulb produces a single slender flower stalk, which may in some cases grow to a height of 10 inches, though they are usually shorter than this. The cylindrical flowers are 2½ to 3½ inches long and come in various shades of red or pink. In some cases, the red comes in the form of speckles on a background of pale yellow, and this is the source of the name “punctata,” which means spotted.

The flowers are not the only part of the plant with spots, since the pointed leaves often have dark purple spots, though these are not always present. They grow through the winter months, going dormant again when summer approaches.

Lachenalia punctata makes a fine garden plant or potted specimen, requiring sun and good drainage. Heavier soils should be amended for successful growing.