A cactus garden can be as big as you want, even 1-2m² o a good cactus bed. But also bigger areas over 100m² can be beautifully planned.
Ideal accompanging plants are hardies e.g.Yucca, Delosperma, Sedum, Sempervivum, Orostachys, Rosularia, Penstemon, Oreganum, Eremurus, Allium, Asclepias bushes wjich can stand dry conditions, slow-growth conifers etc.
A cactus garden must only watered by dryness between March and June.
Manuring necessary in March and May, preferably with " Blaukorn/fertilizer" 30-50gr.m²
meaning: plants should be on rain sheltered side of house (east side) or under roof projection from a wall (southside). Also suitable : roofed pergola or terrace, or unheated greenhouse (open ventilation all year round!). Cheapest and best, however, is open-ended plastic covered greenhouse.
An ideal combination of hardy cacti is e.g. Opuntia, Echinocereus, Escobaria, Sclerocactus, Pediocactus, Gymnocalycium, Mammilarien and other frost hardy cacti which need rain protection. Such a cactus garden can be combined with the following frost-hardy plants: stem-producing and small-growth Yucca, Dasylirion, Nolina, Agaven, Delosperma and other outdoor succulents.
A cactus garden that get no or little rain must be additionally watered from early March till late Juni. Ideal is to water once a week and every 14 days add normal commercial liquid fertilizer. With Echinocereus, Yucca, Nolina, Dasyliron, Agaven, con tinned watering till mid September is good, to achieve additional growth.
Important is to as certain whether or not the plants need rain shelter in winter. Any sin table container can be used, so long it with stands frost and doesn't contaminate the plants.
Watering and fertilising is nearly the same as for cactus garden with rain protaction except that after watering the containers should be thoroughly damp.