Grevilleas are a favourite in gardens across Australia, and it’s easy to see why. This unfussy native shrub comes in a wide range of colours and sizes, and can flower non-stop through the cooler months, with some varieties flowering year-round.
Here are some insights on how to plant, grow and care for these indigenous beauties, as well as trouble-shooting advice on common problems these plants can experience.
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.
Popular Grevillea Varieties
With over 350 species and new cultivars, it’s impossible to cover every type of Grevillea! But if you’re just starting to consider these beautiful plants, here are some of the most successful and rewarding types to grow.
- Grevillea Preissii – With grey foliage and rich, raspberry flowers in tight clusters, this variety is vibrant and eye-catching. Also known as Sea Spray, it grows well in sandy or limestone soils, growing to a height of about 1m and flowering from autumn to spring.
- Grevillea Crithmifolia – This soft and pretty ground cover is a spreading shrub that can reach a height of up to 1m. It produces clusters of white flowers from winter to spring that have a beautiful scent.
- Grevillea Nudiflora – With green leaves and red flowers, this basic variety of Grevillea is a hardy, low-growing ground cover that thrives in almost any conditions, growing well in frosty areas and flowering through the spring.
- Grevillea Excelsior – This is a large shrub that can reach up to 3-4m in height, with green foliage and flame-orange flowers that bloom in winter through spring. It makes a fantastic feature plant for a garden, bringing in plenty of birds, butterflies and beneficial insects.
- Honey Gem – This is a hybrid mix of Grevillea banksii and Grevillea pteridifolia, creating a semi-tropical shrub that grows to about 3-5m in height and produces golden yellow flowers for most of the year.
It’s a favourite with birds and butterflies, and tends to grow tall rather than wide with pruning.
- Grevillea Rosmarinifolia – This is a smaller Grevillea that’s well-suited to growing in patio containers and pots. With pink/white flowers and pointed, silvery green foliage, it resembles the rosemary plant after which it is named.
It can reach up to 1.5m in height, and is also widely used as a hedge plant.
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 fertilizer, 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.
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!
What is the Best Fertilizer for Grevilleas?
Like other native plants, Grevilleas are very sensitive to phosphorus, so it is important that whatever fertilizer 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 fertilizer.
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 fertilizer 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 fertilizer, 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.
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 fertilizer 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.
Make Your Garden a Celebration of Native Plants with Beautiful Grevilleas!
Our team loves all plants, but indigenous Australian plants have a special place in our hearts, and Grevilleas are one of the best!
Easy to grow throughout the country, sun-loving, colourful and hardy, these plants shine in any setting, whether they’re being used as a ground cover, centrepiece, hedge, or screening shrub.
With their ability to flower for months through the winter and attract beautiful nectar-eating birds, it’s easy to see that every garden deserves its own Grevilleas!