Coprosma (Mirror Bush)

How to choose a coprosma

Colour is the main choice. The Green and Gold Coprosma and the Lemon and Lime Mirror Bush sit at the bright end, useful for lifting a dark corner or contrasting with deep green hedging. The Karo Red Coprosma is for those who want dark, red toned foliage. The Rainbow Surprise Coprosma and Mirror Bush Evening Glow are multi coloured forms whose tones shift through the year.

Most coloured cultivars are compact shrubs of about 1 to 1.5 metres if left alone, and all can be held lower by clipping. Expect the colour on any coprosma to be at its richest in autumn and winter and to soften to greener tones in summer heat.

Where coprosma works

Coprosma comes from New Zealand and suits cool temperate, warm temperate and subtropical gardens. It takes full sun, strong wind, salt spray and sandy soil, so it is one of the easy shrubs for a beach house or an exposed balcony. In the tropics it tends to be short lived. It tolerates light frost once established, but young plants are frost tender in cold inland districts and need cover for the first winter or two.

One caution applies. The plain green mirror bush, Coprosma repens, is an environmental weed along the southern coast, where birds spread its seed, so plant the named coloured forms only and keep any coprosma away from coastal bushland.

Full sun gives the strongest colour, and in shade the leaves turn greener and growth opens up. For companions, see our coastal and salt tolerant plants, the plants for pots and the low maintenance shrubs.

Planting and spacing

Plant in spring or autumn, or after the last frost in cold areas. Any soil that drains will do, from sand to improved clay. For a low hedge or border, space plants 50 to 60 centimetres apart. As single shrubs in a mixed bed, allow about a metre. In a pot, use a quality potting mix and a container at least 30 centimetres wide, and expect to pot up after two or three years. Water in well and mulch.

Care basics

Water regularly until the plant is growing strongly, then only in long dry spells. Coprosma is drought hardy once established, though potted plants need steady watering through summer. Feed lightly in spring with a slow release fertiliser. Too much nitrogen pushes soft green growth at the expense of colour.

Clip to shape two or three times through the warm months. Light, regular trimming keeps the plant dense and coloured to the ground, and it responds well to being shaped as a ball, a low hedge or a standard. Cut out any shoot that reverts to plain green, taking it back to where it started, because green shoots are stronger and will take over a variegated plant. Pests are few. Scale sometimes appears on plants in still, shaded spots and is treated with horticultural oil.

Common questions

Why has my coprosma lost its colour?

Colour fades in summer heat and in shade. It returns as nights cool in autumn, and it is strongest in full sun.

Is coprosma frost hardy?

Established plants take light frost. Protect young plants in cold inland districts until they have some size.

Can coprosma be grown as a hedge?

Yes. It makes a dense low hedge up to about a metre with two or three trims a year.

Is mirror bush a weed?

The plain green species is an environmental weed on the southern coast. Grow the named coloured forms and keep them away from coastal bushland.