Sharp Shooting

A shot from a while back from the glasshouse at R.H.S. Wisley Gardens , with a part of the display of Cacti and Succulents .

(All cacti are succulents but not all succulents are cacti ).

The common linking characteristic of cacti and succulents is the ability to store water in the leaves or stems enabling them to survive in arid habitats. All cacti are succulents, yet cacti are defined by the presence of areoles (specialised sites where spines form) whereas succulents have none.

 

The majority of cacti and succulents grow in desert and savannah situations with low moisture, dry air, bright sunshine, good drainage and high temperatures. However there are succulents such as Schlumbergera and Epiphyllum which grow as epiphytes in rainforests. These require semi-shade and humid conditions. So to cultivate cacti and succulents successfully it is best to research their native habitat, to provide their ideal growing conditions as far as possible.

 

Cacti and succulents utilise the Crassulacean acid metabolism (CAM) photosynthetic pathway. Although this makes the best use water, it is much less efficient than other photosynthetic pathways, hence the slow growth of cacti and succulents compared to other plants.

How to care for cacti and succulents typically grown as houseplants

Compost

 

The compost must be open and free draining, to help prevent waterlogging and recreate natural habitat. Cacti compost is readily available from garden centres. Alternatively, use John Innes No 2 with up to 30 percent extra grit or fine gravel by volume, to help with drainage.

 

Re-pot pot-bound plants in spring, into a pot only slightly larger in diameter.

 

Holding spiny specimens can be tricky when re-potting so use thick strips of folded newspaper as tongs or an oven glove.

Position

 

Most cacti and succulents can be placed on a sunny or bright window all year round. Forest-growing epiphytes such as Rhipsalis, however, need semi-shade.

 

During the winter it is beneficial for plants to have cool night temperatures of 8-10°C (46-50°F) as a minimum, for a period of rest.

 

Central heating is not usually a problem for these plants over the winter; just remember they need sufficient water to prevent them from shrivelling.

Watering, feeding and ventilation

 

Spring and summer

 

From April onwards water cacti and succulents freely, allowing excess water to drain away

The compost should be allowed to dry out slightly between waterings, rather than keeping it constantly moist

Forest-growing epiphytes will benefit from a humid atmosphere

Feed established plants once a month during the growing season (April-September) using either a liquid houseplant feed or specialist liquid cacti feed

Cacti and succulents need fresh air and particularly need good ventilation during the summer months

 

Autumn and winter

 

From about September onwards reduce watering to a minimum, to encourage a period of rest

Allow the compost to virtually dry out before watering

Some desert dwellers can be left un-watered from early November to the end of February especially if they are away from overly heated rooms

Winter-flowering types will require warmth and regular watering during this time, to be then followed with a resting period in summer

 

Ideally use tepid rainwater for watering. The minerals in tap water builds up in the soil and can cause deposits on the leaves of succulents.

Flowering

 

Cacti and succulents will perform and look better if you allow them to follow their natural seasonal pattern. A period of rest, to mimic the dry season, to be then followed by an increase in water to act as the rainy season will ensure a good display of flowers. Always check as to what seasonal treatment is required as some will need to rest in the winter to then flower in the spring, while others will rest over summer to flower in the autumn.

 

Pruning and cleaning

 

Pruning depends on the habit of the plant and is not often necessary. Propagation is a great way of tidying up an old plant, reducing the height of leggy specimens and thinning-out overcrowded pots.

 

Dust can build up on cacti and succulents and make them look unsightly. Keep on top of the dusting by using a soft paint brush or blusher brush to remove the dust from in and around the plant. A damp cloth also works really well on smooth succulents.

 

Propagation

 

The habit of the cacti and succulents will give you an indication as to which method of propagation will suit it;

 

Branching habits can have their side shoots and stem removed to produce stem cuttings.

Columnar types are propagated by stem cutting.

Clump-forming species readily produce offsets which can be lifted and divided.

Some fleshy leaves make great leaf cuttings, which are so simple and great fun.

 

Cuttings and offsets

 

Most cuttings require time to dry and produce a callus on the wound, this can take from a week to a day depending on size and type. Use John Innes No 1 with up to 30 percent by volume of added grit and keep the compost on the dry side to prevent the cutting rotting off. Always check what your individual specimen will require.

Seed

 

Many species can also be grown from seed;

 

Use John Innes No 1 with added grit or sand for added drainage

Sow the seed in spring. Large seed will need a covering of one to two times the depth of the size of the seed. Small fine seed should not be covered, but mix the seed with a little sand to help with an even distribution

Water with a misting bottle or a watering can with a fine rose and cover the pot with a sheet of glass or plastic bag. Keeping them at 21°C in partial shade

Allow air into the pot daily by removing glass or plastic bag and wiping off condensation

Keep moist but not overly wet

Pot on seedlings when they are big enough to handle. It can take up to 12 months for them to reach this stage

info from RHS website with thanks .

 

Done