Succulent Container Gardens
Alpines and succulents actually grow best in poor soil. Pots are the perfect way to provide these typical rockery plants with conditions to suit, and will help to draw attention to their often tiny features.
Under normal garden conditions, where the soil has been improved and fed over the years, alpines and succulents will grow tall and lanky, flower poorly and die prematurely. But where there is low soil fertility and free drainage, they grow strong and stocky, and produce abundant flowers. Here, perennial species, such as aubretia, candytuft, gentian, pinks (Dianthus) and saxifrage, will live to a ripe old age.
In their natural habitat, alpines root in rock crevices or pockets of gritty soil, so in pots most prefer a coarse compost, but one which holds a certain amount of moisture. Succulents, such as lampranlhus and sedums, often grow in little more than rocky debris in the wild. Houseleeks, or sempervivums, earned their common name because they will even grow when 'planted' between the tiles of u leaking roof. There, they spread their tightly packed rosettes to plug the hole.
Plant in a Shallow Container
Alpines do not need deep soil or compost, so sinks, seed pans, shallow troughs and the like make ideal containers. Whatever pot you use, it must be free draining, so be sure to provide plenty of holes and a good layer of drainage material in the base.
The leaves of many alpines will go brown and rot if they touch wet compost, so it is a good idea to cover the surface with 2.5cm (1in) mulch of coarse grit, granite chippings or gravel. Including a few large craggy stones in the arrangement will add to the alpine effect. You could even plant a sempervivum in a stone with a hole in it, or in an empty shell for a seaside theme.
Fill the container with a proprietary alpine compost. This will contain a mixture of loam, peat or peat substitute and sharp sand, or grit, to ensure that the plants' roots do not become waterlogged, plus just enough fertilizer to get the plants off to a good start. Alternatively, you can make your own mix of one part topsoil, one part sieved leaf-mold or peat substitute, and one part grit or fine pea shingle.
Most alpines are not drought tolerant, but equally they hate waterlogging. This means that the compost must he kept reasonably damp, particularly during the growing season.
For really healthy specimens, give your plants a weak liquid feed as they begin their growing season. Choose a feed with a fertilizer suitable for flowering plants, but avoid one containing a high level of nitrogen, which will encourage straggly growth.