About the genus
Adromischus is a genus in the Crassulaceae family, and is related to Crassula, Cotyledon and Tylecodon. There are over 30species and subspecies which are mostly grown by collectors for their wonderful variation of leaf shapes,textures, colours and markings.Older plants often form stems that bear the leaves spirally around them.
Adromischus are found in southern Africa, from the south of Namibia,down into the arid Western Cape Province and around the southern part of South Africa right into the Eastern Cape Province.
Plants of this genus bear flowers on long wiry stems from summer into autumn in the UK. The floral characters can be a useful means of identification and the genus has been divided into five sections based on these characteristics.
Most species in the genus are relatively easy to grow in a greenhouse, conservatory or bright windowsill in the UK.
How to grow them
The main growing times are March to May and again from mid-August to November and plants should be watered every one or two weeks ensuring that the compost is fully dry before they are watered again. They like a rest in summer (mid-May to July) with no water usually required and they will also appreciate just a little water occasionally in the winter months. Feed regularly in the optimum growing seasons with a low nitrogen fertiliser such as Chempak No. 8. A minimum temperature of 5°C is ideal.
They prefer a bright spot with plenty of sunshine. A coat of greenhouse whitewash (Coolglass) is best applied for the hottest months to prevent scorch. Be careful in the spring after long cloudy spells. Additionally, use of fans for air movement in the greenhouse is a real benefit.
Adromischus prefer a gritty, porous compost. An ideal mix is to sieve John Innes No. 3 through a 6mm meshed garden sieve to remove the unwanted bulky, organic material and mix in a ratio of 50:50 with horticultural grit.
Mealy bugs can be a problem with all Adromischus species, so regular inspections are required with treatment as necessary. Mildew can also be an issue. The flowers produce a thick sticky nectar that drops on to leaves which can produce a sooty mildew. There are proprietary fungicides that can help, but watering over the leaves when it is warm can help wash any nectar residue away.
Most plants available to buy are produced from leaf cuttings as seed is rarely available and very slow to grow. To propagate almost all species, gently tease one or more leaves off the stem and leave to dry for a couple of days. Bury the leaves at a slight angle to a depth of about one quarter of the length of the leaf in moist, but not wet, compost with the heel of the leaf in the soil. Place in a bright, but not too sunny, spot and the leaf will root in a few weeks and, after some time, will develop a new plantlet from the base.
Text and photos by Andy Palmer
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