How to grow succulents in gardens
This week, we shall look at how gardeners can grow succulents. Indeed, they make excellent landscape plants and can grace any garden. And they are not too difficult to grow since, for the most part, they generally look after themselves. Although they may be grown in pots indoors, the most spectacular displays of succulents are those that are grown in the garden. Here they are in their element and take on an appearance that is otherwise not possible if they are grown in pots indoors.
But the choice of site is important. Succulents will not grow well in clay soils since these soils become easily waterlogged after rain and succulents will suffer from root rot and die off. However, to reduce this problem, they may be planted in raised beds composed of sand, small stones and compost. Such a soil mixture will be better aerated and drained and so will prevent waterlogging. And succulents can do well on steep slopes with shallow soil. And unlike many garden plants, most succulents grow well in full sun.
Succulents are hardy plants and do not require copious amount of water and the soil should always be allowed to dry out between waterings. In fact, more succulents die from overwatering than from anything else.
However, if plants are not watered for a long time, their roots will begin to die back. The amount of water to be added will vary according to the season. During the summer season, water the plants more thoroughly. Early morning is generally the best time to water since this allows plants to dry out during the heat of the day and so prevents rotting. Some species must be kept dry if frosty weather persists for a long time. Such plants will then dehydrate and this will prevent them from freezing. If succulents are well watered during frosty spells, their cells will absorb this water and expand. The cells will now split and the plants may then die. The best way to determine when to water is to examine the soil for moisture, and moisture metres are helpful to check this.
The choice of succulents to grow in your garden is largely determined by the local climate. Most succulents are drought hardy and do well in our climate with its low, unreliable rainfall. They will also generally tolerate high temperatures and hot, bright sun. Only a few species need shade since if they are exposed to too much sun, they may suffer from sunburn damage and may become scarred.
Although most succulents can survive extremes of temperature, some species may not tolerate frost and below freezing temperatures. And even if they do tolerate frost, they may only do so for brief periods of time. During heavy frosts, the tips of stems may be damaged and stems may even collapse. If you live in an area that experiences frost, and wish to buy frost sensitive succulents, then you will need to protect them; for example, by wrapping up the trunk. And they should be planted in a place that is well sheltered from cold, southerly winds, such as against buildings. However, it is better to buy succulents that can withstand frost, especially if you live in those parts of the country that might experience heavy frosts, such as the Kgalagadi. But in northern areas, such as Chobe, where frost is a rare event, frost sensitive succulents may usually be grown successfully.
The choice of succulents to grow may also be determined by the amount of care that the gardener wishes to provide. For those with limited time at their disposal, choose those species that can pretty much look after themselves.
Succulents are most often grown as indoor houseplants and often add a splash of welcome colour to offices and homes alike. Here they may be grown in boxes or pots. Although they may be expensive, porous clay pots are ideal since they dry out quickly and so help to minimize the problem of rotting. Ensure that pots have drainage holes at their base to allow excess water to drain freely and so prevent rotting. In order to receive sufficient sun, they may be placed on windowsills or in doorways. Where adequate light is provided, plants will be much healthier and so will require less care. However, if the window faces north, plants may become exposed to temperatures in excess of 40 degrees Celsius during exceptionally hot spells when the plants may turn yellow in colour. At such times, plants may be temporarily removed to a cooler, more shady part of the building during the hottest time of the day.
Succulents may also be grown in greenhouses. This allows for the cultivation of a much wider variety of species since the gardener can easily control the environment. For example, by heating the greenhouse during cold winter nights or using large fans on hot summer days.
Gardeners should ensure that pot succulents grow in a suitable growing medium. Depending on the species, garden soil, small stones and compost may be mixed to provide such a medium in which succulents can thrive. Composts can be bought in large bags and they should contain sufficient organic matter, be loose, well aerated and drained to prevent waterlogging and rootrot. The organic matter can also increase the ability of the compost to absorb nutrients, such as nitrogen, phosphorous, potassium and calcium. Chemical fertilisers can also be added; for example, compound NPK fertilisers which contain nitrogen, phosphorous and potassium. An NPK fertiliser, such as 3: 2: 1, contains more nitrogen and so will promote more growth. Other fertilisers, such as 2: 3: 2, contain more phosphorous which encourages better disease resistance whist a more potassium rich fertiliser, such as 3: 1: 5, will result in better flowering. However, only a little fertiliser should be added since, unlike many vegetables, succulents are not heavy feeders.
Succulents may be raised from either seed or cuttings. Seeds are inexpensive and are long- lived. Pots or seed boxes may be filled with a planting medium and the seeds sprinkled over it. A shallow layer of coarse grit may then be used to cover the seeds. Cuttings are best taken during the summer growing season. Stem cuttings may be obtained from the parent plant using a sharp pruning saw, or even a kitchen knife, if the stems are thick. However, for thinner stems, a pair of secateurs may be used. When taking cuttings from species that have spines, always use a thick cloth, or even a blanket, in order to prevent injury to yourself and the plant.
Once cut, the cuttings should not be planted immediately. This is because they may require several days to heal since the cut end must form a hard layer before it is planted. To encourage the growth of new roots, the cut end of the cutting should be dipped in a rooting hormone which is usually sold in powder form in small tubes or containers. Once healed, the cuttings can then be planted upright in boxes or pots. Succulents may also be propagated from leaf cuttings. Once removed from the parent plant, allow the leaves to heal before planting them upright.
From time to time, succulents may need to be pruned by using a pruning saw or pair of secateurs. Pruning is needed for several reasons. For example, to promote growth, to remove dead or damaged parts of the plant, or to give the plant a better shape. Finally, dirt may be removed from plants using a small sprayer bottle filled with water, or a stiff brush.
Finally, where can gardeners obtain succulents? Although some specimens may be dug up in the bush free of charge, most plant nurseries usually sell some succulents, usually aloes. Nurseries stocking a wide variety of succulents include Sanitas in Gaborone and a nursery in nearby Mokolodi; the latter specialises in succulents.