Grevillea, How to grow.
The Genus Grevillea is one of the most widespread over the continent of Australia. Its distribution ranges from the tropics of northern Australia to the temperate areas of Tasmania, from the deserts of central Australia to the alpine areas of the Australian Great Dividing Range. Different species have adapted to different climatic areas so to answer the question “how do you grow a Grevillea” might not be as straight forward as you might think.
But then again maybe not!
Grevillea is made up of over 300 species and subspecies as well as hybrids that number into the hundreds. Not all of these are in cultivation and most are not readily available in nurseries, but I think it would be safe to say that if you look hard enough you can probably find at least one or two that will suit the conditions in your garden, will be very easy to grow, flower for an extended period and require little or no maintenance.
So here’s what you need to know in a nut shell.
1. Never fertilize your Grevillea. Grevilleas are a member of the Proteaceae family of plants and have evolved a very sophisticated root system that is very efficient at finding the nutrients it needs in very impoverished soils that are low in phosphorus. High phosphorus fertilizers will kill your Grevillea. In fact I don’t recommended fertilizing your Grevilleas at all, even if it’s low phosphorus and designed for natives. The only exception being if you were growing your Grevilleas in pots or containers or if you had a problem with phosphorus in your soil as I do. Therefore to summarise, don’t fertilize them and don’t plant them near plants (or lawns) that you do fertilize.
2. Don’t plant them in an area where the water tends to sit or doesn’t drain away. Plant them either on a slope, in a raised garden bed or in reasonably well draining soil. Most Grevilleas don’t like too much water around their roots. Of course though there are exceptions. I’ll list some of these shortly.
3. Don’t cultivate around their roots. Grevilleas have lots of surface roots and if you do, you will probably damage the roots and maybe kill the plant. If you do this by accident just water the affected area with a solution of Seasol. This may help.
4. Plant the right type of Grevillea for your climate and soil conditions.
5. Most Grevilleas are very drought tolerant so water for the first summer to establish then only when they really, really need it after that. Therefore don’t plant them near plants that need lots of water to survive.
6. Prune your Grevillea after flowering. Now pruning isn’t essential but you will find that most Grevilleas respond very well to pruning and if you do prune your plant it will look a lot neater and tidier, flower more profusely next year and will probably live a lot longer.
Grevilleas tolerant of poorly drained soil. There are many grevilleas that will tolerate poor drainage. Most are lesser known and not readily available at nurseries, the exception being Grevillea Robusta aka the Silky Oak. This Grevillea grows into a large tree but the great thing about it is that is can be used as the rootstock to graft lots of other more difficult species and hybrids, therefore making these Grevilleas a lot more adaptable. So if you have a space where the water doesn’t drain away very well, then a grafted grevillea could be a good option. Some examples that I’ve grown with this rootstock are Grevillea “Billy Bonkers”, “Pink Ice” and “Lollypop”, but there are many, many more. Just finally, I have found that Grevillea Robusta does appear to have some tolerance of phosphorus in the soil.
Grevilleas that are easy to grow. These grevilleas are adaptable to a variety of soils, climates and are reasonably easy to source. There are so many to choose from. Here are just a few that are common or easy to find in nurseries.
Grevillea Robyn Gordon, Superb, Ned Kelly, Peaches and Cream, Coconut Ice, Strawberry Sundae (all Grevillea Banksii x bipinnatifida hybrids).
Grevillea Long John
Grevillea Rhyolitica, Deua Flame.
Grevillea Sea Spray
Grevilleas for tropical areas. This could be a case of where do you start here. There are so many spectacular Grevillea hybrids that come from the tropics. Most of these Grevilleas won’t tolerate frost but I have found that Grevillea Moonlight seems to be the most tolerant of cold conditions. Here’s just a few.
Grevillea Honey Gem
Grevillea Misty Pink
And the list goes on and on
Grevilleas for arid/desert areas. Most of these are more suited to well drained sandy/gravelly soils. They are very drought tolerant and some have some very spectacular flowers. Most aren’t readily available in most nurseries though, but can be found in specialist nurseries. The other great thing is that most can be grafted onto more reliable rootstocks, so these grafted grevilleas do make them much more adaptable.
Grevilleas tolerant of frost. The news here is that most Grevilleas will tolerate at least some frost, especially since many desert areas have temperatures that drop below freezing at night during the winter. Most of the tropical grevilleas are the exception here but if you get light frost once or twice a year they may still be worth trying. As plants get more established their frost tolerance does increase and Seasol is also meant to help with a plants frost tolerance.
So just as the size, colour and shape of the Grevilleas leaves and flowers varies so does the range of climatic and soil conditions. There are grevilleas that suit any gardener’s tastes and Grevilleas that will suit any garden or position in the garden you wish to plant them.
The important thing to remember when you’re selecting a grevillea at your nursery is that just because it’s in your nursery doesn’t mean that it will grow in your area or in your soil. Ask the nursery person first otherwise just take the risk, give it a go and you may actually discover that the grevillea that isn’t meant to grow in your area or in your soil actually does. That’s what I often do. You may make a new discovery and learn something new.
Anyway next time you’re at your plant nursery give a Grevillea a try, follow the 6 tips I’ve listed above and let me know what you think.
Possibly Related Posts:
- Grevillea "Pink Ice"
- Grevillea Petrophiloides
- Grevillea Rosmarinifolia
- Silky Oak, what you really need to know
- Grevillea Robusta, an alternative way to grow.