|For the vast majority of keen cactus and succulent collectors and growers these are exotic subjects which need to be grown in an artificial environment. It is not simply that they won't survive cold winter conditions as many will not be harmed by comparatively cold conditions which they may well encounter in their natural habitat. The limiting factor is that for many growers in Europe and North America the cold winter conditions are also those of the greatest rainfall. Cacti and succulents do not like the combination of wet and cold, naturally receiving most precipitation in their natural environment in the warmer months when they are in active growth.
They are limited numbers of species which will tolerate the cold and wet winter conditions. For further information on these I would recommend Benny Møller Jensen's website as a source of information. In tropical areas there may be no problem with low temperatures but often problems due to excessive rainfall, here again cacti and succulents will need some protection.
Most cactus and succulent growers that have more than a few plants grow them in some sort of greenhouse. I am often surprised that collectors will spend relatively large sums of money on acquiring unusual and beautiful plant specimens but will spend little or nothing on creating a suitable environment for them. This is a pity because a nicely presented collection can be a joy to behold.
The choice of structure will depend on lot on your local climate and also on what sort of plants you want to grow and how closely integrated it is to be with the rest of your living space. Critical factors for the plants will be light, temperature and air. Given that these basic requirements are met we find that these plants are very adaptable and it is amazing the range of different plants from different natural environments which we manage to grow we manage to grow together.
Most cacti and succulents grow in areas where there is not a great deal of shade and quite a few come from high altitude or almost alpine environments. It is therefore important to maximise light availability where the plants are growing. The further north you live in Europe or North America the more critical this will become. (southern hemisphere growers are generally not sufficiently far south for this to be a problem). Growing areas need large areas of glass or transparent plastic to achieve this. At the most northerly locations or other poorly lit areas supplementary artificial light may be needed particularly during the dark winter months. There is unfortunately somewhat of a conflict with temperature requirements because the more northerly locations will also be the coldest and the growing area will therefore need better insulation to obtain reasonably economic satisfactory temperature differential. Double or triple walled plastic can be used in such environments and its insulation properties is much better than that of glass. It is worth noting that larger structures with a lower surface to volume ratio are significantly easier to keep warm.
In more northerly locations sun-rooms or conservatories built as part of the main dwelling and taking advantage of the heating of the living accommodation may be a more economic proposition. In more southerly locations summer overheating may be a problem and adequate ventilation (either natural or forced) is vital. In some areas a roof with no walls (or ones which can be removed) may be a better solution. In any case air movement is very good for the health of the plants and even in a completely closed environment use of fans to circulate the area is highly recommended.
As some of us have discovered to our cost, cacti and succulents are very heavy plants and often the normal benching supplied for greenhouses is inadequately strong. It is therefore highly recommended to use heavy duty benching.
How big a greenhouse you can have will of course depend on the space available, but all collectors will advise you to have as large a one as you can manage as it will soon become full.. There is a secondary benefit in that the environmental conditions are more stable in a larger structure and less prone to rapid overheating or great heat loss. Think carefully about the width of the greenhouse.as certain widths are inherently inefficient. With a single central pathway anything more than 3 metres (10 foot) wide means either too wide staging to comfortably reach all the plants or wasted space on an excessively wide path. You need to go up to around 6 metres wide before a two path system with a central bench starts to enable efficient use of space again.
Often second-hand greenhouses can be purchased very cheaply but you will probably have to dismantle, move, clean and repair the structures to make them usable. If you are looking for a bargain sometimes excellent second-hand greenhouses come up on eBay. Click here to see the current auctions for greenhouses in the USA and click here for greenhouses in the UK.
If time is more important to you than cost have a look at the greenhouse kits supplied by major suppliers. One such is Greenhouses And Greenhouse Kits.