The Cultivation Page
Whatever the size of your collection of succulent plants, I hope that you find the following hints and tips useful. This information is of a general nature, based on the accumulated experience of many growers. However, the owner of this page cannot accept liability for any plant loss, or damage, or personal injury arising from use of this information.
Two types of pots are available, clay or plastic. The choice is mainly a matter of personal preference. Plastic pots are lighter, cheaper, require less watering and are easy to keep clean. Clay pots can provide stability for tall plants and can mitigate the effects of over-watering, but their accumulated weight requires strong greenhouse staging. Whichever type of pot is chosen, it must have a drainage hole and the bottom should be lined with several pieces of broken clay pots or large clean gravel to assist with drainage.
Many different types are available commercially, ranging from John Innes soil based composts to peat based and recycled garden composts. Add horticultural grade sand and grit to make the mixture porous; the final compost contains between 30% and 70% grit. You may have to experiment a little to find the best proportions of compost, sharp sand and grit for your growing conditions and using locally available materials.
Some of these, usually succulent plants from winter rainfall areas (e.g. Lithops, Conophytums and some other Mesembs, Testudinaria elephantipes, Tylocodons, a few Aloes) grow during the autumn and winter months. Their watering should reflect this.
Lithops (left) should be watered from the early Summer to the early autumn (May / June to the end of September in the Northern hemisphere). Flowers usually appear from late August into the Autumn, depending on the species. Water is then withdrawn as the weather becomes colder, and the outer skin allowed to shrivel to a papery epidermis, before watering commences again in the Summer.
Conophytums (left) tend to have an even later autumn / winter growing period, and generally flower at the beginning of their growing season. Watering should be during the late summer - early autumn and spring, with a break during the coldest winter months.
However, keep an eye on the condition of your plants and start watering before they dry out too much, or they may not recover from their resting period.
Most garden lovers and those with specialist collections of plants would agree that a greenhouse is an asset to any garden. Ideally, a free-standing greenhouse for cacti and succulents should be positioned with the ridge running north-south to maximise the light received all year round. A greenhouse positioned so that the ridge runs in an east-west direction will receive more winter light, which could be useful if it is to house mainly succulent plants that grow during the winter. In either case, it is best to avoid locating a greenhouse where it will be in shadow for a substantial part of the day, to near to trees or in areas subject to strong winds. Positioning the door away from the prevailing wind will help to reduce drafts. Areas of land subject to local flooding should also be avoided. If the greenhouse is sited too far away from the house it may be difficult or expensive to provide supplies of electricity or gas.
Greenhouses either have an integral base, or need to be erected on a purpose-built base. A solid floor provides a clean surface under foot and helps to keep out pests. It is an advantage if a solid base slopes slightly to encourage water to drain away. Drainage channels may be moulded in to the concrete to direct water out of the building. However, if you want to plant larger columnar cacti into the ground, then foundations should be constructed around the planting area.
As with the greenhouse frame, staging can be made of wood or metal, with similar advantages and disadvantages of the materials. After watering, plants become very heavy in their pots. Clay pots are heavier than plastic ones and a peat-based compost is usually lighter than one based on loam (e.g. John Innes). Solid staging, while sturdier makes it easier for mealy bugs and other pests to gain access to plants. Slatted staging lets the air circulate, but pests can still move over it fairly easily. Slatted staging is unsuitable for use with capilliary matting or gravel.
There are several methods for heating greenhouses and cold frames during the winter. Electric fan heaters work well, but are expensive. They produce dry heat, so plants require spraying during the winter on sunny days. Tubular electric heaters are available but the plants need air circulation to keep them at their best. If electrical heating is to be used it is worth investigating Economy 7 or similar tariffs. Gas heaters are very successful, but need pipes laid from the house (or heavy cylinders) and installation can be costly. Paraffin heaters work well and are cheap to run, but can produce a paraffin smell, and need to be used carefully to avoid a fire hazard or sooty plants.