Europeans have been cultivating mesembs for some three centuries. During this long period of captivity, some species have thrived and have even been naturalized in the more temperate parts of the northern hemisphere. Other species have persisted very well in greenhouses. But many species - Chiefly the small and seemingly fragile sphaeroids have resisted cultivation in exile; they have never become what Schwantes called "permanent guests". A few observations on the art of mesemb cultivation may aid growers in extending the life of their collections. Indeed, in some cases we maybe able to extend the life of species.

"Difficult" plants can he grouped in three categories: quasibiennials; species with special diets; and the so called "winter-growers". (Some devilish species fall into all three categories!)

Winters of discontent

The winter-grower category is the largest. The term is unfortunate, for very few plants actually prefer to grow in the depths of winter: both the low light levels, and the high humidity, are hardly conducive to robust growth I suggest that "winter-grower" be altered to the more accurate, if prolix, "autumn-and-spring-growers" or "short-day plants" After all, days begin to shorten immediately after summer's equinox; all plants sense this change and respond to it.

Many collectors wonder how far forward they can shill the growth cycle If "winter" growth can be induced in autumn, can it be pushed further forward, even into summer? Summer growth would have all sorts of advantages. free air movement in the glasshouse, abundant light, no frost, an absence of winter pathogens I have therefore made hundreds of experiments along the lines of acceleration and have found two broad categories of mesembs.

1. Strict short-day plants. In this category we have, foremost, all members of Mitrophyllinae (e.g., Monilaria, Diplosoma, Oophytum), most members of Leipoldliinae (Cheridopsis, Antimima). Short-day plants will not respond to prolonged summer watering, or rather, they will respond by expiring.



2. Uncommitted short-day plants. This category involves plants which grow in autumn and winter in habitat, but which, in cultivation, will respond flavourably to water at other seasons. It includes virtually all conophytums. Many collectors have been bulled into believing that their "conos" should not grow in summer Even though the plants show signs of bursting their sheaths, most growers think: I have done something wrong, thus plant should not grow now. But in fact conos are perfectly happy to grow from midsummer onwards. As soon as their old leaves have been reduced to a papery shell, the new leaves can emerge, encouraged by a few light waterings.

Fig. 1 Conophytum rugosum subsp. rugosum  S.A. Hammer
This species must receive water in summer lest it develop
terminal rugosity.   Photo: John Trager

I should note that all short-day mesembs, however strict their adult regimes, are happy to germinate in summer. At the seedling stage, they will accept water regardless of day length. Indeed, summer growth is the strongest growth, and it is certain that strong seedlings produce strong adults. The early advantage is permanent.

Soil requirements

Most mesembs are not gourmets; they are not really particular about an exactly balanced pH, good drainage being much more important to them. But some species do require extremes of acidity or alkalinity. In the former category we have such things as C. turrigerum (Fig. 2), which occurs on acid granite and which will not long survive alkalinity. Conversely, many Knersvlaktian species (Dactylopsis, Diplosoma) only grow well when given an alkaline, salty, and silty mixture. The best medium is a sticky clay.

Fig. 1 Conophytum turrigerum (N.E.Br.)  N.E.Br.
An acid loving species quickly distressed by alkalinity,
it thrives on rainwater.   Photo: John Trager

La vida breve

Most of us hope that our plants will outlive us. But only a pessimist would have such a feeling in regard to Diplosoma! This genus consists of two species; both live for only a few years (I have grown them for 10 years but this is exceptional). With such plants one must accept that a renewal every two or three years is necessary. A few conophytums are virtually biennials as well. One must alter one's concept of permanence: the gene pool persists, but its manifestation is transitory.

After me, the deluge?

Watering is the most critical aspect of cultivation. As we have seen, it is the key to unlocking dormancy, but it is also critical in a day-to-day sense. And I mean day-to-day: when plants are in really active condition, I water them virtually every day.

Mesembs enjoy frequent shallow waterings. Just because they can store water doesn't mean that they need or prefer to do this; they are much I happier when watered lightly and often. This also keeps the root system in a better more responsive, condition. Some people advocate occasional deep floodings as a more "natural" method of watering, but this the key to unlocking dormancy, but risks rot, and also tends to induce it is also critical in a day-to-day sense. ruptures and Frankensteinian scars, which spoil the aesthetic joys of horticulture.

Finally, all mesembs, difficult or easy, respond to feeding. Misting with a dilute fertilizer solution is beneficial to all plants, adult and juvenile. As a general rule, if one cannot see a much response to fertilizer within a day of it's application, the root system is in trouble. Above all, plants want to grow.