How to grow osteospermum

Grow osteospermum in a sheltered spot in well-drained soil in full sun. They are perfect for adding colour to containers as they flower for months from May through to September. African daisies can also be used as bedding plants to fill gaps in borders. They look great planted in containers with grasses and other summer bedding plants.

When to plant osteospermum

Many osteospermum varieties are tender or half hardy, so plant them out after the last frosts, typically between late May and early June, depending on where you live. If growing osteospermum from seed, sow indoors between February and April.

How to plant osteospermum

Sow seed indoors between February and May into seed trays filled with seed compost. Add a light covering of vermiculite or seed compost and put in a warm place to germinate. Once seedlings have their first set of true leaves, prick them out and plant individually into small pots. Plant out once the danger of frost is over.

If buying one of the many ready-grown varieties, wait until the danger of frost has passed before planting into containers or the border. Plant with the top of the root ball level with the soil or compost, firm in and water well after planting.

How to care for osteospermums

Water new plants regularly until established. After this, osteospermums in borders should be able to cope with less frequent watering. Those growing in containers will need regular watering during hot weather.

Feed weekly through the growing season with a general plant food to encourage continuous flowering.

Some varieties of osteospermum are tender or half-hardy, particularly in cooler areas. These can be grown as annuals or moved indoors in autumn to overwinter. Move pots under cover to a greenhouse. Species that are H3 (hardy down to -5ºC) can be overwintered in mild areas. To overwinter in the border, cut back and lay a mulch around plants to help protect them from the cold.

How to propagate osteospermum

Take cuttings of osteospermum as insurance in case plants don't make it through the winter. The best time for taking cuttings is in spring or late summer. Select a non-flowering shoot and cut the tip off, strip the leaves and dip in hormone rooting powder. Plant several cuttings in well drained compost around the edge of a pot. Water well and pot on when roots have formed.

Pests and diseases

Osteospermums can attract aphids. Hand squash any small infestations or spray them off with the hose. Encouraging wildlife into your garden can also help to reduce pest infestations as aphids are a good food source for birds as well as ladybirds and hoverflies.

African daisies are also susceptible to verticillium wilt. This is a fungal disease that can cause dieback, wilting and death. There is no cure, so dispose of any affected plants. Don't put any diseased material in the compost heap. Osteospermums can also get downy mildew, which is spread by airborne spores. Plants are more susceptible to it if the foliage in wet weather and a lack of air circulation around the leaves. Avoid leaves and aim at the roots when watering and remove any affected foliage.

Osteospermum varieties to grow

Osteospermum ecklonis has beautiful white blooms, which are deep blue on the reverse of the petals, with a dark blue centre.
Height x Spread: 1m x 1m

• Buy Osteospermum ecklonis from Burncoose Nurseries

Osteospermum jucundum var. compactum has narrow, green foliage and has the added bonus of being an attractive, weed-suppressing ground cover plant with purple flowers through summer and into autumn.
H x S: 20cm x 60cm

• Buy Osteospermum jacundum var. compactum from Beth Chatto

Osteospermum jucundum 'Tresco Purple' has vibrant purple flowers that appear over a long period from June until September.
H x S: 30cm x 30cm

• Buy Osteospermum jacundum'Tresco Purple' from Crocus

Frequently asked questions

What is the lifespan of the osteospermum plant?

Annual osteospermum plants will live for one growing season. Perennial varieties are generally short-lived with a lifespan of around two to three years.

Are osteospermum perennial?

There are both annual and perennial varieties of osteospermum, but they are often treated as annuals because they are half hardy and won't survive a cold winter outdoors. However, perennial varieties can return the following year if they are given protection from winter cold and frost.