How to grow cactus plants from seed

Growing cactus plants: jump links

• Where to grow cacti
• How to plant cacti
• Caring for cacti
• Cacti problem-solving
• Cacti varieties to grow

Where to plant cacti

Cacti need a sunny spot in very well-drained compost, such as cactus compost, to thrive.

For best results choose a south- or east-facing windowsill. You may need to find an alternative spot for them in winter if the windowsill becomes too cold.

How to plant cacti

Always plant cacti with care. The spines can prick and hurt your skin. It's a good idea to use common kitchen items such as a thick tea towel, spoon and fork to help you plant your cactus, so you can avoid hurting yourself.

Plant cactus in a very free-draining compost such as cactus compost. Alternatively use a peat-free multi-purpose compost with added horticultural grit or vermiculite, to aid drainage.

Mulch with a layer of horticultural grit or pebbles to complete the look of the pot display. This also prevents water splashing back on the cactus.

Kevin Smith, Gardeners' World Magazine, explains how to create an attractive display using cactus plants, in our No Fuss video guide. Kevin explains why salad tongs are the tool of choice for handling cacti, which compost to use, and how to create a decorative mulch:

Caring for cactus plants

In summer, water cacti no more than once a week. A good watering less often is better than a little-and-often approach. You shouldn't need to water cacti at all in the coldest months.

Repot cacti every couple of years, to give them fresh compost – you won’t necessarily need to pot them into a larger pot.

In this Golden Rules video, Stan Griffin of Craig House Cacti reveals his three top tips on growing cactus plants with success, including when to water and feed, and when not to. He also gives advice on how to take cuttings from cacti.

Growing cactus plants: problem solving

Cactus plants are usually trouble free. If overwatered or not given enough light they can rot at the base. This is usually fatal for the plants.

Cactus plants can develop spindly growth but it's easy to rectify. Emma Crawforth, BBC Gardeners' World Magazine, explains all, in our Quick Tips video.

Cactus varieties to grow

• Echinocactus grusonii – golden barrel cactus is globe-shaped but eventually grows tall. Native to Mexico, it bears bright green stems with spiked ribs. Bright yellow flowers appear in summer.
• Gymnocalycium paraguayense – a variable cactus with flattened spines. It produces creamy white flowers in spring and summer.
• Mammillaria spinosissima – a globe-shaped cactus with bright pink, funnel-shaped flowers. Its central spines are a reddish-brown or yellow.
• Rebutia krainziana – a clump-forming barrel cactus, forming dark green stems up to 7cm in diameter, with contrasting small, white areoles and spines. In late spring large, yellow or red flowers develop around the main stem, forming a tight clump.

How to grow cactus plants from seed

Cacti are exciting to grow from seed – their plump seedlings appear quickly and they’ll begin to develop their characteristic spines in under a year. Cactus seeds are available from seed merchants and specialist societies, but if you know someone with a fruiting plant, then you can get yours for free. The best time to sow cacti seeds is late February or March.

You Will Need

• Cacti seed
• Small plastic and terracotta pots
• Free-draining compost or cactus compost
• Vermiculite or fine grit
• Sheet of glass
• Fork or spoon
• Tweezers
• Gravel

Step 1

Cactus seed grows best when fresh, so harvest your own from fruiting plants like this melon cactus (Melocactus). Ripe fruits are fleshy and colourful. Split them open and remove the seeds, then clean off any flesh as this can cause mould to develop. Place the seeds on a sheet of kitchen towel to dry out for a couple of days. Another option is to buy dragonfruit from a grocer – these exotics contain thousands of small seeds that will develop into vine-like cacti.

Step 2

Fill a pot with a moist, gritty, free-draining compost. Gently firm down and level the surface. Scatter your mixed cactus seeds over the surface, taking care not to sow them too thickly.

Step 3

Gently sprinkle a thin layer of vermiculite or fine grit over the seeds, covering the whole surface of the compost. Leave the pot in a greenhouse or on a warm windowsill, covered with a clear plastic bag to preserve soil moisture.

Step 4

Seedlings will develop within a few weeks. Remove the plastic bag and water when the compost becomes dry, but spray the surface with water regularly, to keep it moist.

Step 5

The following spring, your seedlings should be ready to transplant. Use a fork or spoon to gently tease out individual cacti, taking care not to catch the spikes on your skin.

Step 6

Part-fill a small pot with gritty compost and gently ease the cactus seedling into place. Use tweezers to ensure the seedling is not sitting at an angle.

Step 7

Fill around the seedling with compost and water well. Add more compost if necessary and then use the spoon to arrange gravel around the seedling. Keep in a sunny spot such as a windowsill, and pot on as and when you need to.