About the genus
This is a genus in the Aizoaceae family that currently consists of about 107 recognised species plus additional subspecies and varieties.
Each growth on a plant consists of a partially or wholly fused leaf pair (often called a head) that is renewed each year. These leaf-pairs can vary from a few millimetres to 50mm tall.
Some species maintain a solitary habit for many years, but most can replace a single leaf-pair one year by two or more pairs in the next to form clusters.
With a few exceptions, flowers are produced from August to October and there is a wide variation in colour: white, yellow to orange, light to dark magenta and even dark maroon.
Furthermore, flowers open during day or night, depending on species,and individual flowers can open and close for about two weeks. The night-flowering species have the bonus of strong pleasant scents to attract pollinators.
They are found in the wild in the western part of South Africa and south-west Namibia, an area that receives rain during winter with largely dry summers. Consequently most of their growth is during the cooler months.
How to grow them
The most important factor in growing conophytums is correct watering. Keep plants dry from the end of March until late July; during this period the old leaves dry up to cover and protect the new leaves which are developing. Watering can be restarted in the second half of July or early August, but only when there are cool nights (ideally below 15°C),otherwise they cannot respond to water. With moisture, new heads will quickly expand and push through the old leaf sheaths. Watering can then be continued on about a weekly basis until mid-October when one can start to reduce it, until by mid-winter it might only be once every three weeks. When the weather starts to warm in mid-February, watering frequency can be increased once again through March. During winter the plants require all the light that is available and a minimum temperature of about 2°C.
The genus is relatively pest-free, but the biggest danger is sunburn which can occur in April/May when we get our first hot sunny days. Paint shade on the greenhouse glass over the conophytums by mid-April,removing it at the end of September. Growers with smaller numbers of plants sometimes move them around their greenhouse or conservatory to more shady places for summer, freeing the sunny areas for winter-dormant cacti. Ventilate as much as possible.
The best time to repot is during the August–October period and for containers over 8cm use pans rather than pots because most conophytums have shallow root systems. A compost of 1:1 mix of John Innes No. 2 or 3 and coarse granite grit should be suitable. It is reported that neat mineral mixes such as Moler clay are not satisfactory for conophytums. Repot every few years when plants have reached the edge of their pans, but frequent repotting will encourage plants to grow more quickly.
Text and photos Terry Smale
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