Grevilleas – Gardener’s Guide to Growing This Australian Native

What are Grevilleas?

Named after Charles Francis Greville, these plants are part of the Proteaceae family and are native to Australia. There are over 350 species and even more cultivars on the market, with flowers ranging from cream and yellow to pink, orange, red and lilac.

Grevilleas are all about variety, so there’s a type for almost every garden. In addition to ground covers and small shrubs, there are great screening varieties, trees and even weeping standards.

Dwarf Grevillea Varieties

Of course, some growers may not be looking for a large growing grevillea, but still hope to add the beautiful allure of the grevillea to their garden. Luckily, there are some fantastic dwarf grevillea varieties which offer an alternative. 

Here are some of the most successful dwarf varieties to grow. 

• Grevillea Lanigera Dwarf - This is a perfect choice for rockeries, native gardens or to simply grow in a pot. It has fine dark green foliage, and striking masses of cream and pink flowers which bloom over a long period. It requires little pruning and only the occasional fertiliser throughout the year. 
• Grevillea ‘Pink Midget’ – This is a low-growing, long-flowering compact species perfectly suited to small gardens or container growing. It flowers best in a full-sun spot but can adapt to a semi-shaded spot. 
• Grevillea ‘Lara Dwarf’ – Often only reaching 30 cm in height, the lara dwarf is a long spreading cultivar with rolled leaf edges and short branches. It produces creamy leaves with a light pink blush which bloom from April to October.

Grevilleas For Hedging

Many of the grevillea species are the perfect choice if looking for a flowering hedge. Varieties like the Rosmarinifolia and Ivanhoe are popular choices due to their dense growth habit and fuss-free care. 

Grevilleas are known to be fast growers and vast spreaders, which make them a great choice if you want a quick-growing hedge. Plus, many need little additional watering after being established, so it won’t be a hedge you’ll have to continually worry about. 

If you’re planning on using grevilleas for hedging, it is good to choose a variety which responds well to light pruning as this will help you maintain size and shape of your hedge throughout the year. 

If you are looking for more hedging options, see our list of Australian natives perfect for hedging.

How to Grow Grevillea Plant

As with all plants, you need to start by selecting the right spot if you want the best results!

• Climate – As native plants, they tend to thrive in all climates across Australia. However, some varieties are more frost-tolerant than others, so be sure to check before you buy if you live in a colder area with winter frosts.
  
  
• Sunlight – These plants are sun-loving, so they require a position in full sun to semi-shade. The more shade the plant receives, the fewer flowers you’ll get, and growth may be stunted. Ideally, it should receive a half-day of sun at a minimum.
  
  
• Water – These are water-wise plants that thrive in the Australian climate, but they do need a bit of extra care in the first two years. They do best if watered regularly once or twice a week after planting (especially if it is very hot), but can manage on rainfall once they are well established.
  
  
• Soil – The soil needs to be well-draining or the roots will rot. Ideally, the soil should be loose and even sandy, with lots of well-rotted organic matter and mulch. If you have clay soil, start by mixing in plenty of gypsum, mulch and organic compost.
  
  
• Nutrients – Because it is a native plant, it requires little or no fertiliser, although a dose of a slow release low phosphorus fertiliser like a 13-2-13, a 14-0-14 or a native blend fertiliser every 2 months is recommended, especially in the first year of planting.

How to Prune Grevilleas?

Grevilleas respond well to light pruning after flowering season is over, and tip pruning during the flowering season can help encourage more blooms.

If the plant is looking a bit leggy and you want dense growth (for example, for a hedge or screen), then cut back by about one-third to stimulate thick, bushy growth.

Propagating Grevilleas

The best way to propagate Grevilleas is through cuttings, a method that has a much higher success rate than seeds. Here’s how:

• Using clean, sharp shears, take a cutting from hardened new growth of 7-10cm. This growth usually appears after the flowering season, from October to the following March. Make sure the cutting is in good condition and free of disease.
• Trim leaves off the lower end of the cutting without tearing or damaging the bark. Remove any young shoots or flowers.
• Dip into a rooting hormone.
• Plant into a low nutrient propagation soil mix. 1 part peat moss to 2 parts coarse sand works well. You can use soil that the parent plant is growing in.
• Mist the soil to keep it moist, and keep the pot away from direct sunlight in a warm, bright room.
• New roots should appear in 4-8 weeks, and you can plant it once new growth appears about 3-4 months after that.
• Try with several cuttings at once, as this gives you the best chance of success – the extra plants make great gifts!

Pests and Diseases

This is a very hardy shrub that is resistant to most pests and diseases, which is a great benefit of using native plants in your garden. The most common issue is insufficient sunlight and boggy, waterlogged soil.

On rare occasions, it may suffer from the following:

• Sooty mould – Also called blotch or black mould, this can be washed off with a weak, soapy solution, fungicide, eco-oil or neem oil.
  
  This fungal issue is caused by mould spores feeding off the honeydew left by sap-sucking insects, so it’s important to treat any infestations of aphids or mealybugs quickly with an organic solution.
  
  
• Phosphorus toxicity – These plants are very sensitive to phosphorus, and have evolved over time to use the very small, trace amounts of phosphorus in native soil.
  
  If your fertiliser has too much phosphorus in it, it will start to burn the plant, causing yellowing on new growth and scorching on leaf edges.
  
  Stop using that fertiliser on or anywhere near the Grevilleas plants, thoroughly soak the soil with water to leach remaining phosphorus out of the ground, and the plant should recover.

Grevilleas Frequently Asked Questions

What is the Best Fertiliser for Grevilleas?

Like other native plants, Grevilleas are very sensitive to phosphorus, so it is important that whatever fertiliser you use has 2% or less phosphorus. Look for an organic 13-2-13 or 14-0-14, or ask your local nursery for a native plant fertiliser.

Do Grevilleas Grow Fast?

Yes! They grow exceptionally quickly if they are positioned in the sunlight and supported with water and a low-phosphorus, native plant fertiliser in the first year. They are long-lived too, with many plants living 50-60 years.

There are many different varieties ranging from ground covers to screening shrubs and full trees, so check your variety first to see the full height and spread you can expect.

Do Grevilleas Have Invasive Roots?

No, these plants have a shallow root system, so they are not a threat to pipes, paving or walls. You can plant them as screening trees or shrubs without worrying that they will damage the structure with their root systems.

You should cover your bed with a good layer of mulch to keep these shallow root systems moist and healthy.

Can Grevilleas Be Grown in Pots?

Yes, but it has to be a compact variety. Be sure to look through the different cultivars and species to find one that is the right size for your container, and be sure to place your container in full sun to semi shade for the best flowers.

Use a well-draining potting soil with plenty of organic matter, feed regularly with a light dilution of low phosphorus fertiliser, and water when the top 2cm of soil is dry.

Can Grevilleas Grow in Clay Soil?

These plants generally don’t do too well in heavy clay soil, so it’s worth improving the soil before you plant. Add plenty of well-rotted organic matter, mulch and gypsum to improve the drainage, and break up dense clumps of soil to make it easier for the roots to grow.