Fockea edulis is one of the more unusual and distinctive species of the Asclepidaceae, or the milkweed family, noted for its huge underground caudexes which can ultimately grow in excess of 21 inches in diameter, and tip the scales at over 100 lbs. The plants produce a branching tangle of vining stems, which in habitat, can exceed several meters in length. The growth of vines in some plants is said to become so rampant that it will eventually choke out the plants upon which they grow. Under cultivation, the growth rate of most plants is more modest, at least in my plants – with the vines adding about a foot or so of growth each year. The leaves are an attractive, dark glossy green coloration, and are oval to lance shaped, and are rather small, to about 1 to 2 inches in length and about 1 inch wide, although on my plants, these are smaller -
In habitat, this species is a true geophyte, with the majority of the plant, (a stem or root modified to store moisture and nutrients through drought and other environmental stresses), lying deep underground. In times of severe drought; both the leaves and vines are deciduous, leaving only a small stump above ground to mark the location of this plant. The underground caudex enables the plant to persist through extreme drought, sometimes surviving for several years without measurable rain. When the rains return, the plants will produce a flush of growth; in good years, adding a considerable growth of vines, and adding significantly to the weight and size of its underground caudex. In cultivation, many growers choose to reveal the huge caudex by lifting a good portion of it above the soil line when repotting. This is the best way to stage this plant, but whenever the caudex is exposed in this manner, the portions which are exposed virtually cease to grow -
Fockea edulis is native to South Africa and southern Africa. Unusual for members of the asclepidaceae, or milkweed family, this species has the reputation of being edible (as indicated by its name “edulis”). It apparently served as an emergency food for the Hottentots who consumed the tubers after they had been specially processed to remove or neutralize any toxins that may be present in these plants.
I have found this to be an easy and undemanding plant, tolerating benign neglect without complaint -
Even under the best of conditions, it will take at least a few years to produce an impressive caudex, and probably at least 7 years to produce truly huge caudexes: so this may not be a plant for those who demand instant gratification. Having said this, even a small plant with a modest sized caudex can be staged in a small bonsai pot and make quite an impression -
In fall, when temperatures start to cool, bring this plant indoors for a long winter dormancy, during which it should be maintained at cooler temperatures and drier conditions. This plant will not tolerate frosts -
Over the years, this species has been regarded as one of the standards of the caudex producing succulents, indeed, many of the books on cacti and other succulents have treated this species as something of a “gateway” plant, the one generally recommended for beginners who are interested in starting a collection of caudex plants. I do not entirely share this view: on the one hand, this does appear to be a relatively easy plant to grow, presenting few challenges, and on these grounds, it is a reasonable choice for people who are new to growing caudex plants, but it also has a few drawbacks which may render it a less than a perfect match for many growers. Possibly the most significant issue is one of availability – In my decades of growing succulents, I have never seen this plant in any of the nurseries or garden centers – even ones with a better than average selection of cacti and other succulents: this will probably forever remain in the domain of the mail order nursery. Another consideration is that, under normal growing conditions, the greater portion of the caudex of this species, lies hidden from view: to produce a really impressive caudex in this plant, it is necessary to grow it for years, possibly many years, before raising it above the soil line – few growers (beginners or seasoned experts) have this kind of patience. And frankly, the portion of the plant which naturally grows above the soil line offers few enticements: by the standards of most growers, the flowers are quite small and pretty nondescript, and the leaves and vines do not compare well with those of other foliage plants – so for those years when this plant is growing its caudex invisibly below the soil line, the grower may be forgiven for relegating this plant to a more hidden spot at the back of the bench, lest they be asked to justify their interest in this plant before it has sufficiently matured.
In my opinion, a better starter caudex plant would be one which produces the greater portion of its caudex above ground, and which produces large, brightly colored flowers; Pachypodiums and Adeniums for example, and while it may lack the colorful flowers, the ponytail palm also makes an excellent starter plant – and best of all, it is readily available from most nurseries.
Even so, Fockea edulis remains one of the most popular and enduring of the caudex plants, and tops the lists of many growers as an ideal beginner plant for those becoming interested in growing caudiciforms. It is an easy species to grow, presenting few difficulties, and it is a plant with lots of character: by providing a few basic requirements, it is a reliable and long lived species, It may not be for every grower, but is seems once you have grown it for a while, you become hooked.