La Grevillea It is a genus of trees and shrubs that produces very curious flowers. The vast majority of the species that form it are native to Australia, but precisely for this reason they are very interesting garden plants.
And it is that they resist drought quite well, and excessive heat is not usually a problem for them. In addition, they resist frost, so ... let's get to know them better 🙂.
Origin and characteristics
The Grevillea is a genus of shrubs and trees native mainly to Australia, although there are some that live in Papua New Guinea and the islands north of Australia. It is believed that there are more than 500 described species, but today there are only 370 accepted.
They grow from 0,50 to 50 meters in height, with a trunk that can be creeping or straight. The leaves are generally evergreen, but in cold climates they behave like deciduous. These are pinnate-lobed, green in color. And the flowers, which usually appear in spring, are grouped in relatively large and colorful inflorescences.
The most popular species are:
Robusta grevillea
Image - Flickr / Tatters
It is an evergreen tree known as Australian oak, fire tree or golden pine that can reach a maximum height of 50m, although in cultivation it does not exceed 25m. It is an ideal plant for medium-large gardens, since it does not take up as much space as you might think at first and it is good to maintain.
Resists up to -7ºC.
Grevillea juniperina
Image - Wikimedia / Christer T Johansson
It is an evergreen shrub endemic to eastern New South Wales and southeastern Queensland in Australia. It reaches between 0,2 and 3 meters in height, and produces red, pink, orange, yellow or greenish flowers.
Resists up to -5ºC.
Grevillea Golden Yu Lo
Image - helsieshappenings.blogspot.com
It is an evergreen shrub that reaches a height of 3 meters and a width of 2,5m. Its inflorescences attract especially attention, since they are of a very beautiful intense yellow color.
Grevillea baileyana
Image - Wikimedia / Tatiana Gerus
It is a tree native to the rainforests of northeast Queenslad in Australia and Papua New Guinea that can reach 30m, although the normal thing is that it stays between 10-15m. The flowers are grouped in whitish inflorescences when mature.
Resists up to -2ºC.
What are their cares?
If you dare to have a copy, we recommend that you provide it with the following care:
Location
They are plants that they must be abroad, in semi-shade or, better, in full sun. If you opt for tree species, plant them at a minimum distance of 5-6 meters from paved floors, walls, etc. to avoid problems.
Earth
- Garden: from experience I can tell you that they grow better in those that have good drainage and are slightly acidic. The very compact and calcareous soils do not allow them to have good health; Therefore, in case yours is precisely like this, make a 1m x 1m planting hole, put shading mesh all around it and fill it with substrate for acidic plants (like this one that you can buy here) mixed with 30% perlite.
- Flower pot: They cannot be kept in a container for too long, but during their first years they will be fine in them if they are grown with universal growing medium (you can get it here) mixed with perlite in equal parts.
Irrigation
The frequency of watering will vary greatly as the seasons go by. Thus, while in summer you will have to water very often, the rest of the year it will not be necessary to do so much. But how often do you have to give it water? Well, more or less it is recommended that they be about 3 or 4 times a week during the hottest and driest season of the year, and about two weekly the rest.
In case of doubt, we must check the humidity of the soil, either by introducing a thin wooden stick (if it comes out practically clean when it comes out, we can water) or by using a digital humidity meter which will tell us instantly how wet it is.
Likewise, it is important to use rainwater, lime-free, or acidified if the one we have is very hard (diluting the liquid of half a lemon to 1l / water)
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Guano powder.
From early spring to late summer we will pay them with ecological fertilizersand guano.
Multiplication
The Grevillea multiply by seed in fall / spring and cuttings in spring. Let's see how to proceed in each case:
Seeds
The step to follow is the following:
- First, a forest seedling tray is filled with universal growing medium.
- Then, it is watered conscientiously and a maximum of two seeds are placed in each alveolus.
- They are then covered with a thin layer of substrate and watered again, this time with a sprayer.
- Finally, sprinkle with copper or sulfur to prevent the appearance of fungi.
If all goes well, they will germinate in 1-2 months.
Cuttings
To multiply them by cuttings you have to cut a piece of about 40cm, impregnate the base with homemade rooting agents and plant it in a pot with previously moistened vermiculite.
In about 1 month it will emit its own roots.
Rusticity
Image - Wikimedia / Eric in SF
It depends on the species, but generally they endure weak frosts from between -2 and -7ºC.
What did you think of the Grevillea?