How to grow grevilleas
Want to add colour to your winter garden? Grown all over Australia, grevilleas are fuss-free, native shrubs that flower, flower and flower – they really don’t know when to stop! They come in a great range of sizes, from groundcovers and mid-sized shrubs to tall screening plants, which are perfect for privacy. Their year-round flowers are also simply irresistible to native birds and insects. The toughest thing about growing grevilleas is choosing which ones to plant!
How do I grow them?
Climate
Grevilleas will grow in most climates. However, cold and frost tolerance varies between species – always check the plant label when buying.
Aspect
These beauties are sun lovers, so plant in full sun and keep sheltered from strong winds.
Soil
Grevilleas need welldrained soils. Consider building raised garden beds or, in large gardens, form beds as elevated mounds with free-draining soil. A few weeks prior to planting, dig into the soil a combination of well-aged cow manure and blood and bone. Avoid using fresh manures, as these can burn the plant roots. If growing in pots, use a potting mix formulated for natives, such as Debco Native Mix Superior or Osmocote Professional Native.
Feeding
As grevilleas are sensitive to excessive levels of phosphorus, you need to use a specialised native fertiliser, such as Yates Acticote Natives or Osmocote Native Gardens. Feed them twice a year – once in spring and again in late summer
Watering
When planting, water in well with a seaweed-based solution, such as Seasol. Follow up by watering twice a week for two to three weeks, then once a week for about four weeks. Water more in hot, dry weather and less in winter or cooler, moist conditions. After the plant is established, it can withstand periods of drought but, if watered during dry periods, it will grow and flower better.
Mulching
A layer of mulch over native garden beds will help retain soil moisture, suppress weeds and protect roots. Use organic mulch such as compost or lucerne and spread about 50mm deep around the plants. Take care not to pile mulch around the stems, leaving a clear ring at least 10cm across.
Pruning
You can tip prune during the flowering months to encourage more blooms. If the plants are looking a little leggy and tired, cut back by about one-third during the warmer months, ideally after a heavy flush of flowers, to stimulate bushy new growth.
