About the genus
Graptopetalum comprises about 16 different species which resemble, and are closely related to, Echeveria and Sedum. They are from Mexico,Sonora and Chihuahua to Oaxaca,and also central and southern Arizona in the USA.
In cultivation Graptopetalum cross easily with the two above mentioned genera and other Mexican Crassulaceae (the family to which all these species belong). Many highly attractive, easily grown hybrids are offered by garden centres and supermarkets. Sadly, they do not often carry their correct names of × Graptoveria (Graptopetalum × Echeveria),× Graptosedum (Graptopetalum× Sedum) or Graptophytum (Graptopetalum × Pachyphytum) but the label ‘mixed succulent’ seems more common.
The very popular plant that was previously known as Tacitus bellusis nowadays considered to be a Graptopetalum (G. bellum). It was found that a separate genus Tacitus was unwarranted because the differences in flower colour and morphology were attributed to a different pollinator.
How to grow them
The larger the leaf on the Graptopetalum (or hybrid of), the easier it is to grow. G. paraguayenseis the easiest. It is hardy in the Channel Islands and is grown outdoors right across the Mediterranean.
The most succulent species and probably the prettiest is G.amethystinum which looks just like a Pachyphytum until it flowers.The winter hue of its leaves is amethyst in colour and the red speckled flowers are typical of the genus. These very succulent species perform well in full sun in a greenhouse, conservatory or on a windowsill and like all Mexican succulents require a dry winter (no water from October to the beginning of April) and will grow well if watered once a week in summer. Do not stand plant pots in water and allow plants to dry out after each soaking.
Plants are not fussy when it comes to compost, any well-drained medium will do. No fertiliser is required (see below).
A few of the small-leaved species are tricky to cultivate: G. rusbyi, G. mendozae and G. filiferumrequire special cultivation; however,almost all plants labelled G. filiferum in the UK are hybrids of this species and are much bigger than the 2cm rosettes of the true G. filiferum. Hybrids are easy to grow but the small species dislike full sun and dislike overwatering.
All species will grow a new plant from a single leaf. If a leaf is dislodged by accident, merely place it in a shaded spot on top of compost. It will root in a week or so, after which it can be watered. A new plant will grow from the spot where it was attached to the mother plant.
These plants will extract all the nutrients they need from any rock material (grit/gravel), so a topdressing is all that is needed. If Graptopetalum are even given a half-strength low-nitrogen feed,they will bolt, lose their colours and become etiolated, especially if grown on a windowsill.
Text and photos Ray Stephenson
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