About the genus
This genus of 25 to 30 species is found in southern Peru, western Bolivia and north-west Argentina. It was created by American botanists Britton and Rose almost exactly a century ago, the name being an anagram of Bolivia, though some of the species had been known since the 1840s.
Species have been incorporated into Echinopsis at times, and are often labelled as such in collections, though there is evidence that they are not very closely related.
Lobivias usually have flat-globular to short-cylindrical stems. They are often quite spiny; the spines being carried on ribs that are sometimes straight but often twisted or broken up into tubercles. The flowers are an important contributor to their popularity as they are freely produced and come in a wide range of colours and also a few different shapes and sizes. In some species, plants grown from seed from a single parent can produce flowers of different colours whereas other species are more uniform. It can be tricky to identify variable species.
How to grow them
Lobivias adjust well to cultivation and thrive under the conditions usually recommended for many cacti. A sunny position in a greenhouse or on a south-facing windowsill is beneficial to encourage flowering and strong spine production. Free-draining soils that allow plenty of air to reach the roots are best, whether they be a loam mix with added grit or based on moler clay or pumice. If you use a soil mix that works for most of your other cacti and succulents, it will be fine for your lobivias.
In such a mix, water often during the growing season but allow the soil to dry between waterings. Be aware that in the hottest part of the summer, especially when nights remain close to 20°C, Lobivia growth will slow or stop, so watering is best reduced until nights are a little fresher.
In winter, once they are bone dry, plants can stand temperatures down to freezing, and even indoors they will need a spell in a cool place to trigger spring flowering.
The main means of propagation are from seed and by taking cuttings. Seed of most species is easy to obtain. Seed from localities which are far-apart might give you quite different-looking plants. Germination is easy and seedlings grow rapidly. In low light they can grow tall and thin but always bulk out when light levels improve.
Cuttings are easy from plants that produce offsets since these often have roots already. If cut at the narrow connection to the old plant they will root easily. Solitary species can be beheaded or have their growing point removed to encourage new growth.
If there is one drawback to lobivias it is that they do not age well and can become tatty as the years go by. Restarting them from cuttings is then worthwhile.
A few species of Lobivia seem prone to damage by mites (probably false spider mites), causing the skin of the plant to become brown. Soapy or oily pesticides (or just very dilute washing-up liquid) can be used to counter mites but often they go away by themselves. The new growth on the plant will be green but reinfestation can happen. Scarred plants can be rejuvenated as described earlier.
Text and photos: Phil Crewe
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