Plant ID card |
|
|---|---|
Botanical name |
Grevillea spp. |
Common name |
Grevillea, grevillier. |
Family |
Proteaceae. |
Origin |
Australia, New Guinea, New Caledonia, Sulawesi (Indonesian island). |
Dimensions |
Depending on the species, the grevillea measures 2 to 3 m high in cultivation. Its tangled branches give it a massive shape with a width of approximately 1.50 m. The shrub reaches its adult size after 3 years. |
Foliage |
The thin, subtly cut evergreen leaves resemble fern leaves. Light green, bright green, silvery or bluish in color, they can appear, in certain species, in the form of needles covered with down. |
Bloom |
The flowering period extends from February to October with a peak from May to July. With their spider shape, the nectar flowers attract the eye with their styles which, once upright, protrude beyond the stamens. The color palette includes reds, pinks, oranges, yellows and whites. |
Fruiting |
They are few in number in cultivation compared to the abundance of flowers and appear as lignified and hard cores which open when ripe. Hybrid varieties are often sterile. |
Exposure |
Sun to partial shade. |
Ground |
Any soil, even poor, as long as it is fresh, acidic or neutral and well drained. |
Rusticity |
Some Grevilleas cannot tolerate temperatures below -5°C while others tolerate them down to -10°C. |
The
Grevillea
genus brings together 360 species of
fast-growing
perennial shrubs
with varied shapes, colors and sizes. They have an erect or creeping habit which makes them resemble a juniper or a large rosemary.
Where and when to plant
Grevillea
?
The most resistant species can be grown in regions where negative temperatures do not drop below -10°C. They require direct sun and well-drained soil. They can be satisfied with partial shade in warmer regions. The most fragile species can only be cultivated in a Mediterranean climate.
Planting must be carried out in spring,
protected from frost for good rooting:
In rock gardens, grevillea can be associated with plants with an upright habit such as agaves or aloes or with a compact habit such as ceanothus or euphorbias;
In defensive hedges (with prickly needles), it can be combined with oleander to benefit longer from a flowering hedge;
Grevilleas with a carpeting habit can be used to decorate a low wall, a fence or any other unsightly support. The grevillier can also be
planted alone
to brighten up a lawn.
If you just have a balcony or live in a cool area, you can grow your grevillea
in a pot.
Combine it with Mediterranean plants, citrus fruits or palm trees. The container must be brought into a cold, bright greenhouse during the winter.
Wear gloves when handling the plant as its allergenic leaves can cause severe eczema. Copyright (c) 2021 Rose Marinelli/Shutterstock. No use without permission.
Also read: Carefree gardening: 10 evergreen shrubs that add a touch of sparkle to your outdoor space!
How to plant the grevillier?
Wear gloves
when handling the plant as its allergenic leaves can cause severe eczema. Sowing grevillea seeds is rather delicate and must be preceded by scarifying and soaking the seeds.
In the ground:
for good growth of your
Grevillea
:
Moisten the root ball by letting the container soak for about 15 minutes in a basin of warm water.
Dig a large hole and place sand and gravel around the roots for good drainage.
Install the grevillier.
Fill in and compact the soil.
Water.
According to the lunar calendar, we recommend planting, pruning and fertilizing during the waning moon.
In pots:
good drainage conditions are essential to avoid root rot. Be sure to install a layer of gravel or clay balls at the bottom of the tank. Then create a balanced substrate based on potting soil, heather soil and sand. Choose a species with limited growth that adapts more easily to growing in a pot.
How to maintain the
Grevillea
?
Watering:
in open ground, the first years after planting, regular but not excessive watering is necessary during the summer season. In poor soils, natural mulching based on plant waste is recommended in the fall to enrich the soil. During the winter, the grevillea must be protected by a winter veil.
In a pot:
ensure regular watering, avoiding letting water stagnate in the saucer. Reduce it in winter;
Fertilization:
plan to add fertilizer low in phosphorus but also repotting in spring;
Pruning:
cut the branches by a third of their length after flowering. Formal pruning can also be done during growth.
How to propagate
Grevillea
?
Like sowing, propagating grevillea is not always successful. It can be carried out
by heel cuttings
(take part of a lateral stem with part of the main stem) at the end of summer. Transplant the stems into a mixture of moistened soil and sand.
What are the diseases of the grevillier?
Rather resistant, the grevillier is however
sensitive to
Phytophthora cinnamonii
, a fungus which blocks the sap-conducting vessels: the shrub dries suddenly. If you notice yellowing of the leaves, this is probably due to the presence of limescale in the soil (iron chlorosis) or in the watering water.
What are the most beautiful varieties of
Grevillea
?
Grevillea robusta is the largest shrub of the genus which produces orange-yellow flowers. Copyright (c) 2018 Mauro Rodrigues/Shutterstock. No use without permission.
Among the many varieties of grevillier, let us cite:
Grevillea rosmarinifolia
: resistant, it is adorned with bright red inflorescences from March to July;
Grevillea robust
has: the largest shrub of the genus which
produces orange-yellow flowers;
Grevillea juniperina
: also called "juniper-leaved grevillea", it forms a bushy bush of bright green, with fine, pointed leaves;
Grevillea johnsonii
: its bright pink flowers wrapped around themselves resemble snail shells.