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 Juniperina
Grevillea Lanigera
Grevillea Long John
Grevillea Rhyolitica, Deua Flame.
Grevillea Sea Spray
Grevillea Speciosa
Grevillea Rosmarinifolia
Grevillea Thelemanniana
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 Formosa
Grevillea Honey Gem
Grevillea Misty Pink
Grevillea Moonlight
Grevillea Sylvia
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.
Grevillea Eriostachya
Grevillea Excelsior
Grevillea Juncifolia
Grevillea Petrophiloides
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.
Grevillea Eriostachya
Grevillea Excelsior
Grevillea Juncifolia
Grevillea Juniperina
Grevillea Lanigera
Grevillea Petrophiloides
Grevillea Rosmarinifolia
Grevillea Speciosa
Grevillea Thelemanniana
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.
Posted: June 6th, 2009 under Grevillea.
Tags: Grevillea
Comments
Comment from leighton
Time July 3, 2009 at 7:09 pm
I want to plant a fence line with the Grevillea Rosmarinifolia as I believe they are hardy and also have spiky leaves which will provide a barrier from unwanted people climbing the fence. I will require about 100 plants and would like to know the best place to get them We are in the central west of NSW Thanks
Comment from Rebel Gardener
Time July 4, 2009 at 10:33 am
Hi Leighton, great question. I’ve decided to write an article about Grevillea Rosmarinifolia to address your question.
Comment from dorothy
Time October 18, 2009 at 11:20 am
We have planted a number of Grevillea Lady O in a triangular garden bed which is surrounded on two sides by cement path/driveway and the third the brick house. They have been in about 18 months looking wonderful but now some are dropping their leaves. Problem? Solution?
Comment from Rebel Gardener
Time October 18, 2009 at 12:00 pm
Grevilleas don’t like fertiliser and most don’t like too much water with inadequate drainage. Sounds like you may have a problem with drainage if your garden bed is surrounded by concrete. Have a dig in the soil to see if it is boggy.
Comment from teresa
Time October 19, 2009 at 3:16 am
I have a long john which I love.I’m not sure how to prune it.It seems when I trim it it doesn’t bush out but stops growing on the trimmed branch.Any suggestions as I’d like to form it a bit more into a tree-life form but don’t want to cut it needlessly and not have it grow in those parts.
Comment from Rebel Gardener
Time October 19, 2009 at 7:15 am
Long John is one of my favorite Grevilleas. It grows fairly quickly and flowers prolifically. There may be a limit though on how hard you can prune it. I’d suggest not to prune it below the previous 12 months growth. If you’ve already tried and had no success then you’ve probably already got your answer. This grevillea is one that’s best tip pruned when young and then shaped each year after flowering. Have you maybe thought of pruning it into a standard? You could then underplant something else (or more long johns) to hide the bare trunk if it wasn’t to your liking.
Comment from Rebel Gardener
Time October 19, 2009 at 7:27 am
I grew Long John once and it grew very quickly into a dense rounded bush of about 2.5m. One day the whole bush got blown over by the wind. What I discovered was the organic mulch was piled up around the trunk causing it to go rotten. The trunk was clear of the mulch when small but then grew out to meet it and disappeared below the branches and foliage. This is one reason why I’m not a big fan of organic mulch.
http://www.gardeningnativeplants.com/mulch/
Comment from Ballarat gardener
Time October 30, 2009 at 1:02 pm
I’ve had no luck with grevilleas at all. The only ones that have flowered are arenaria & jephcottii. Even Moonlight just won’t grow or flower. The others that have died or refused to flower include Rosmarinifolia lutea, “Pink Ladies” and “Flora Mason” as well as the larger flowering types such as Misty Pink. I have no trouble growing lots of varieties of correa, leptospermum, banksias, hakeas, dryandras and eucalypt. If por drainage is the problem should I just give up on grevilleas?
Comment from Rebel Gardener
Time October 31, 2009 at 6:33 am
If you’re not having any trouble growing Dryandras then I wouldn’t think that poor drainage would be the problem. But it still wouldn’t hurt to check. Bad drainage can be solved by using varieties grafted onto Grevillea Robusta rootstock.
You may find the winters in Ballarat too cold for most “tropical” Grevilleas such as G Misty Pink and G Moonlight. The best tropical Grevillea for winter cold areas that I’ve tried is Grevillea Caloundra Gem, otherwise is you like the large flowering Grevilleas you might like to try
Grevillea Ned Kelly or one of the other similar hybrids like G Robyn Gordon, G Peaches and Cream. Just make sure they don’t get too much frost.
You may also want to check your soil PH. It may be alkaline?
Comment from Steve
Time April 18, 2010 at 10:02 am
What is the expected lifespan of most grevilleas, especially Moonlight?
Comment from Rebel Gardener
Time April 19, 2010 at 7:56 am
Hi Steve good question.
Grevilleas can live for many years but in some circles they do suffer from a reputation of being short lived. This is because in some garden circumstances home gardeners are under the misconception that “natives” shouldn’t be pruned and are tempremental and as such they grow quickly (if the condtions are ideal) and in some cases grow lanky and untidy. Because of this the home gardener thinks they’ve run there race so they pull just pull them out and replace them. Hence the reputation. This is a shame because all they really needed to do (in most cases) was prune them back into shape.
Most Grevilleas (and especially Moonlight) respond very well to an annual prune and as such can form a very attractive shrub that will flower for an extended period and live for many years. I know of a Grevillea Moonlight that’s growing in the front garden of a house near Melbourne, that I travel past from time to time. It’s growing against the front wall of the house and faces west. I’ve traveled past there for about 15 years and can only remember it being fully grown so it’s at least that age. It is about 3-4m tall and about 2-3m wide. It gets pruned from time to time and when in flower it looks spectacular.
I recommend Moonlight as a garden plant but it doesn’t like an open frostly area. I’ve heard that in some cases they will tolerate frost but it’s not ideal. If you live in a frost prone area, against a north or west facing brick wall might be the best option.
Although I did see an episode of Burkes Backyard once where Don was standing in the front garden of a house in Bowral (a frost prone area I believe) next to a mature Moonlight and was amazed by the fact it was growing there.
Just in finishing gardeners that grow Aust Natives and replace them when they get, what they perceive to be old, are doing themselves a disservice. Quite often a good prune is all that’s needed to tranform them into a new plant.
I had a neighbour once that used to cut his 3,4,5 m tall Callistemons and Melaleucas back to bare stumps about 1-2m tall and then just sit back and watch them regrow. Of course you can’t do this to just any plant but there are a hell of a lot that you can do this to.
The advice I’d give to any gardener contemplating removing any plant just because it’s old is prune it first and give it a chance to the it regenerate.
Comment from Linde
Time May 31, 2010 at 12:11 am
I have Grevillea Peaches & Cream growing in a large ceramic urn here in Geelong Victoria. It was flowering when I bought it 2 years ago, but hasn’t flowered since.
I don’t fertilize it and we don’t get much frost, but I am geographically close to the Ballarat gardener and like him, I also can’t work out what is wrong. Any suggestions?
Comment from Rebel Gardener
Time June 3, 2010 at 8:34 am
Hi Linde I don’t normally recommend fertilizing most Australian Natives and in particular plants from the Proteaceae family, of which Grevilleas are a member. There is one exception though and that is when they are grown in pots. I will then give them a low phosphorus native fertilizer. This may cure your problem. Another point that many forget about planting plants in pots is in most cases it is best to only increase the size of the pot by one or two sizes when repotting. If the jump in pot size is too great you will find that most of the potting mix won’t have any roots in it for some time and it may become over saturated with water leading to root rot and other problems. If you were starting from scratch I would say replant it a plastic pot that is 1 or 2 sizes larger than the size rootball it has and then place it inside the urn. Seeing it’s been there for 2 years it might be best if you get some good quality Aust native potting mix and repot it into an appropriate sized plastic pot and then place it back inside the urn. Before you do though give it a really good watering first and then leave it for a few hours for the water to drain away. Then when you take it out of the urn check the water content in the potting mix. It should be damp but large areas of it shouldn’t be saturated or still holding excess water. One of the problems with clay, ceramic and most other decorative pots is they have a small drainage hole in the bottom that at it’s best is inadequate and at it’s worst will block easily with roots. At the end of the day though I try not to plant these shrubby types of plants in pots as number 1 they will usually to better in the ground and number 2 they do become dependent on you watering them over summer to keep them alive. I like to plant succulents such as Agaves, Euphorbias, Cactus etc in pots as you can go away for a few days over summer and know when you come home they won’t have dropped dead because it was hot and you weren’t there to water them.
Comment from Linde
Time June 6, 2010 at 8:47 pm
Thanks Rebel Gardener,
I really appreciate your help.
That’s great, thanks!
Comment from Rebel Gardener
Time June 8, 2010 at 8:19 am
Thanks Linde I hope it helped
Comment from sue
Time June 9, 2009 at 5:33 pm
I love the flowers and the way you show them! gardening is one of my biggest passions