Osteospermum – The Cape Daisy – Hardy Evergreen Perennial

The Cape Daisy so named because of a/ its masses of vibrant coloured daisy flowers and b /because it originated in the Southern areas of Africa.

Osteospermum is a low growing, spreading perennial, well suited to a number of uses. In particular it is a good flowering evergreen ground covering perennial that doesn’t get too tall. They tolerate dry conditions well, and for this reason are often thought of as a plant only for dry soils. They grow very well in good fertile soil, moist - not sodden.

Osteospermums have been subject to hybridization and there is now a good colour range and a few interesting flower variations to the normal open daisy flowers which are their big draw. Osteospermum ‘Whirlygig’ being the most unusual of the flower shapes. There are now many colours to this shape of flower.

The ‘crimped’ or ‘spooned’ petals are a photographers dream. So much so, that the ‘normal’ daisy flowers Cape Daisies seep to get ignored – photographically! These are not the hardiest of varieties for garden use, but can be used for patio pots.

The flower colours range from white through to pink, deep red and mauve - with yellow thrown in also. Some of the cultivars have bi-coloured flowers.

The foliage is nondescript – being dark green, with the main ‘attraction’ of simply being evergreen.

It is essential to choose hardy varieties for perennial use. There are many annual and semi-hardy types which are sold in flower for the summer months, or as houseplants.

Where to Plant Osteospermums

Whilst the Osteospermum is quite hardy, it should be planted in full sun – in good soil that is well drained and does not get waterlogged.  A dry sunny bank is the best situation I have seen. It provided a ‘waterfall’ of ‘Day-Glo’ colour. In very dry weather, and evening watering – not a soaking - maybe weekly will keep them flowering.  In this sort of situation, they make a good ground cover and soil stabilizer with their fibrous root system and good foliage cover.

 Osteos – as they are also known – give a good display of flowers in late spring, and then have ‘secondary’ flushes of flower through until the autumn. For the best continuation of flower, dead-heading the faded blooms should be a weekly activity.

As with many evergreen perennials, it is the establishment in the first couple of years that is vitally important – especially through the first winter. Get them though this period, and there should be no hardiness problems thereafter.

A great plus for those living near the coast, is the fact that Osteospermums seem not to be disturbed by salt-laden winds! They are often planted in great numbers with seaside parks departments.

They make good patio pots subjects, and are suited to being grown in large planters - especially because of their good tolerance to dry conditions. However it is essential to keep the plants moist when grown in containers, as they have a tendency to ‘close-up’ in dry conditions.

Propagation of Osteospermum

Seed sowing in early spring is reasonable successful, but get your seed from reputable source. It is not easy to ‘save’ your own seed, and in any event, many are non-fertile in that the flowers do not set seed.

Softwood cuttings in a heater propagator in spring root quite well, though be on the lookout for dead or diseased cuttings in the propagator and remove them immediately. Otherwise, autumn cuttings of a semi-ripe nature are best, but will need to be overwintered in a frost-proof environment to establish as young plants the following spring.

Problems with Osteospermums

Choosing plants which are not of the hardy varieties is one way to failure! Unfortunately, the naming of Osteospermums is not always accurate, so it not always easy to get specific cultivars. Choose reputable nursery grower.

Aphids in the form of greenfly are sometimes a problem – with foliage and also opening flower buds.

In dry conditions during mid to late summer, they can be susceptible to powdery mildew. Treat at first sign with an evening drench of fungicide.

Sometimes, Osteospermum decide to stop flowering in summer. This is as a result of dry conditions, and whilst the plant will easily survive, it will shed its flower buds, and not always reproduce even when weather improves.  This is particularly annoying if grown for patio display. Simple answer being not to let them dry out!

A Selection of Reliably Hardy Osteospermum Varieties. (Even these can succumb in severe winters during the first few years.)

Osteospermum jucundum 'Merriments Joy’ – Vivid masses of deep pink daisies.
Osteospermum ‘Tresco Purple’ – may need a few years ‘acclimatisation’ to become fully hardy.
Osteospermum ‘Snow Pixie’ – Masses of pure white daisies on the dark green foliage.