How to grow houseplant cacti and succulents
Quirky and characterful, these popular drought-tolerant plants thrive indoors and sometimes even outdoors. Spiny or furry, tiny or tall, bold or intricate, they are diverse and endlessly fascinating. In no time you can find yourself with quite a collection!
- Easy to grow and low maintenance
- Drought resistant
- Mostly houseplants, but some grow outside
- Plant in free-draining, gritty compost
- Most enjoy full sun
- Make new plants from cuttings or seeds
- Many produce attractive flowers
All you need to know
What are cacti and succulents?These plants mostly come from dry, arid regions, and are able to survive periods of drought by storing water in their fleshy leaves or stems. They usually like warm sunny conditions when in growth, with low atmospheric humidity, so most are grown indoors in the UK. Some, such as epiphytic cacti come from rainforests and like partial shade, regular watering and higher humidity, so need to be treated more like a general houseplant than a cactus.
A few cacti and succulents are hardy enough to survive outdoors, especially in milder or drier areas of the UK, but it is safest to give them winter protection.
Choosing the right cacti and succulentsMost cacti and succulents are grown as houseplants, thriving on sunny windowsills. They are ideal if you want small, easy-care, fascinating and even quirky plants to enjoy in your home.
Some hardier or half-hardy types can be grown outdoors in sunny, sheltered spots, creating an exotic or Mediterranean look. They are drought tolerant, so perfect in dry summers or low-rainfall areas, and are best grown in containers. Most need additional protection over winter, or can be grown as temporary summer bedding. Check plant labels carefully for growing instructions.
Succulents to try growing outdoors
Hardy cacti and succulents
Cacti and succulents can differ hugely in appearance, from big and bold to small and intricate, tall or rounded, spiky, furry or glossy. Many are grey-green, but colours can range through all shades of green to yellows, dark purples and reds. They can be displayed singly, especially larger specimens, or grouped together in a small collection of contrasting or similar types. Another popular way of displaying small succulents indoors is in an open terrarium.
Getting the right look
Some hardier succulents can be grown outdoors and will add an exotic touch to containers and summer bedding displays in sheltered, sunny spots. They can also be grown in the thin, free-draining soil of rock gardens and green roofs.
Large specimens – such as Aeonium 'Zwartkop' – in terracotta pots can look particularly impressive and sculptural on a sunny patio or doorstep in summer, although most will need protection over winter.
How and what to buyCacti and succulents are widely available in the houseplants section of garden centres, DIY stores and even large supermarkets, as well as from many online suppliers and specialist nurseries. Plants are often small and cheap, sold either singly or in small collections.
Hardier succulents are usually sold with other drought-tolerant plants, or as summer bedding in spring and early summer, in garden centres and from online suppliers.
Where to get ideas and advice
To explore and narrow down your potential plant choices, you can:
- Visit gardens with collections of cacti and succulents in glasshouses or outdoors, so you can see which ones you like best. The RHS Garden Wisley, in particular, has a huge diversity in its glasshouse and rock garden, and succulents often feature in its summer container and bedding displays.
- Look in garden centres and DIY stores, which usually offer a wide range in their houseplants section, or outdoors with other drought-tolerant sun-lovers and summer bedding.
- Go to RHS Find a Plant and select ‘cacti and succulents’ in the ‘plant type’ option, to browse the photographs and plant descriptions, and find out where to buy them.
- Visit RHS Flower Shows to meet specialist growers, and buy a wide range of quality plants.
- Visit a specialist nursery, in person or online.
When to plant
Indoor cacti and succulents are sold in pots of all sizes, depending on the age of the plant. Repotting is best done when the plant has outgrown its pot and the best time is in spring .
If planting the more hardy types outdoors, such as sempervivums and stonecrops (Sedum), this is best done in late spring, once temperatures start warming up.
Various half-hardy or tender succulents are sold as summer bedding in spring and summer, for planting once all risk of frost has passed.
Where to plant
Most cacti and succulents are grown indoors as houseplants, in pots of free-draining, gritty compost. They like bright light, so put them on a sunny windowsill all year round, or even take them outdoors in summer to bask in the sunshine.
Cacti and succulents generally like good ventilation, especially in summer, and cope well with the dry air in centrally heated homes.
There are a few notable exceptions – tropical rainforest-dwelling succulents, such as the Christmas cactus (Schlumbergera) and orchid cacti (Epiphyllum) and Rhipsalis, like more frequent watering and semi-shade, so prefer an east or west facing window, although a south facing window is fine if the plant is placed behind a net curtain to shield it from hot sunshine.
During winter, it's best to give most indoor cacti and succulents a period of rest, with a night temperature of only 8-10°C (46-50°F). Central heating is not usually a problem, as long as the plants are not close to radiators, but avoid watering during this period, as this will promote weak growth. Just offer enough to make sure they don’t dry out excessively and start shrivelling. Orchid cacti however, will require watering when the compost becomes dry
Hardier succulents, such as various sempervivums and stonecrops (Sedum), can be grown outdoors, especially in mild or dry areas of the UK, and in very sheltered gardens. Give them full sun and shelter from rain, especially in winter. They will fare best in containers of free-draining, gritty compost, rather than in the ground. They can also be grown on rock gardens and in dry-stone walls or other similarly well-drained locations.
Slightly less hardy types, such as aeoniums and echeverias, may survive outdoors in the south of the country if given protection from frost and excessive wet over winter, but it is usually safest to bring them indoors.
Prepare your compost or soil
Most cacti and succulents, whether grown indoors or out, are best in containers of very free-draining, gritty compost that will not get waterlogged. You can buy ready-mixed cacti compost, or use John Innes No 2 compost and mix in up to 30 per cent grit or fine gravel by volume.
Hardy succulents can also be grown in the ground in a warm, sunny spot, but the soil must be very free draining, so avoid planting them in heavy clay soils, as these will become too wet especially over winter. Improve dry sandy soil by incorporating some organic material such as well rotted garden compost into the area before planting.
How to plant and repot
After several years, a plant that has increased in size may benefit from repotting if its roots have filled the container or the plant has outgrown its pot. This is best done in spring. Avoid repotting into too large a pot as the excess volume of soil can stay too wet and cause rot.
If grown as decorative houseplants, you may wish to group several plants which look good together into a container that's just large enough to accommodate all of them, or perhaps into an open terrarium. Use a proprietary cactus compost, or make your own using 2 parts by volume of John Innes No 2, with 1 part horticultural grit or sharp sand mixed in. Top off with a mulch of horticultural grit or fine gravel.
Holding spiny plants can be tricky – use thick strips of folded newspaper as tongs or an oven glove to protect your hands.
When planting hardy succulents outdoors in containers, simply follow our guide to container planting. Just be sure to use a proprietary cactus compost, or 2 parts by volume of John Innes No 2, with 1 part horticultural grit or sharp sand mixed in, and top off with a mulch of horticultural grit or fine gravel.
Dust can build up on indoor cacti and succulents, especially the prickly ones. Use a soft paintbrush or blusher brush to remove it regularly. A damp cloth works well on smooth succulents.
Ideally use tepid rainwater. The minerals in tap water can build up to damaging levels in the compost and can leave white chalky deposits on the leaves of succulents.
- Most indoor cacti and succulents should be watered thoroughly once the surface of the compost feels dry to the touch during spring and summer, so check first before you apply water. Let the excess drain away, so they are never left standing in water. Try not to let the compost dry out excessively between waterings during the growing period.
- In autumn and winter, November to the beginning of March, give cacti and succulents a period of rest. Provide cooler conditions with a night temperature of only 8-10°C (46-50°F) and minimal or no watering. Water should only be given if necessary, to prevent the plants shrivelling during this period. Orchid cacti can have more water, but let the compost dry out before watering again. Allowing your plants to have this rest period, should encourage flowering.
- Winter-flowering cacti, such as the Christmas cactus (Schlumbergera), need warmth and regular watering in winter, with a rest period in summer.
- Hardy succulents growing outdoors don't need additional watering once they're settled in. Protect them from excess rainfall over winter.
FeedingTo encourage good growth and flowering, feed once a month during the growing season (April–September), using either a liquid feed high in potassium such as a tomato fertilser, or a specialist liquid cacti feed.
- Move the container into the warmest, driest, most sheltered spot, such as in the lee of a wall or under the eaves.
- Insulate the container with bubblewrap or layers of fleece to help protect the roots from freezing.
- Cover the plants with a cloche, bubblewrap or heavy-duty plastic to keep out the winter wet, as well as the cold. But make sure there are some gaps, as good air circulation is vital. See our guide to wrapping tender plants over winter.
- Give the plants a tidy-up – remove any fallen leaves, debris and dead foliage, as these will encourage rotting.
Caring for older plants
Cacti and succulents can live for many years. Some cacti can be very slow growing, but may need occasional repotting as they expand.
Succulents tend to grow faster and if any have become leggy or ungainly over time, you can always start new plants from cuttings to replace misshapen older plants.
How to encourage cacti to flower
Giving cacti cooler, drier conditions during their dormant period, and as much light as possible all year round, should help to stimulate flowering. The flowers are usually short lived but vibrant.
Most cacti and succulents don't need pruning, although some of the taller, branching succulents can be trimmed back if they get too leggy.
Cut stems cleanly just above a leaf node, and the plant should produce fresh, bushier growth from this point. Any stems that you remove may be used as cuttings to make new plants (see Propagation, below).
The way your cacti and succulents grow indicates the best way to propagate them:
- Branching plants can have the sideshoots and stem removed to produce stem cuttings (see below).
- Columnar cacti can be propagated by stem cuttings.
- Clump-forming or rosette-forming species readily produce offsets (or new small plants) – once well rooted, these can simply be detached to make new plants.
- The fleshy leaves of some succulents such as echeveria or crassula make easy leaf cuttings.
Taking stem and leaf cuttings
- Having removed your cutting from the plant, leave the cut end to dry out and produce a callus. This can take anything from a day to a week, depending on the plant.
- Insert the cutting into a mix of 2 parts John Innes No 1 compost and 1 part horticultural grit by volume. Keep the compost only slightly moist while rooting to prevent rot.
Growing from seed
Many cacti and succulents can be grown from seed – either bought or saved from your own plants:
- Sow seeds in spring into pots or small trays of John Innes No 1 compost with added grit or sharp sand. When sowing small seeds, mix them with a little sand to help achieve an even distribution.
- Cover large seeds with grit, but leave small seeds uncovered.
- Water with a misting bottle or a watering can with a fine rose, then cover the pot or tray with a sheet of glass or a clear plastic bag. Keep at 21°C in a bright spot, but not direct sun.
- Ventilate daily by removing the glass or plastic bag and wiping off the condensation.
- Keep the compost moist but not overly wet.
- Pot on the seedlings when they are big enough to handle. It can take up to 12 months for them to reach this stage.
Cacti and succulents are usually relatively trouble-free, if the correct growing conditions are provided. Poor growing conditions can lead to the following problems:
- Overwatering can damage roots and cause stunted growth, blistering (oedema) and rotting.
- Underwatering is equally problematic, causing shrivelling and slow or misshapen growth.
- Insufficient light leads to weak, misshapen plants, while excessive cold can cause dieback or discoloured patches on the skin.
- Too much humidity or brightness can cause cactus corky scab. Brown patches appear on the skin and slowly shrink to form a scab. Correct the conditions gradually to prevent further outbreaks.
- With hardier succulents growing outdoors, winter wet is the main killer. Most need to be protected with a cloche or bubblewrap, or brought under cover.
Several tiny sap-sucking pests can also attack cacti and succulents, including:
The Royal Horticultural Society is the UK’s leading gardening charity. We aim to enrich everyone’s life through plants, and make the UK a greener and more beautiful place.