Last Updated on October 31, 2021 by Phil
Grevillea is made up a many different looking plants. At first glance, some of them may not even look remotely related to one another. That’s because some grevillea varieties are trees, whereas others are shrubs. And yet, there are many that are flowering plants.
All in all, there are over 360 different grevilleas. You also have a few more hybrids that have been developed. And, more are being created by the day.
But, while their shapes, sizes, and habits can vary significantly, they do share many similarities.
The most common of which is that they are tropical and subtropical in nature. Since they originate from Australia and Southeast Asia, they are used to bright, warm conditions. The good news is, they are now grown all around the work so you can enjoy them as houseplants as well as grow them in your garden.
Grevilleas grow anywhere from 3 feet to 100 feet tall. Their width varies significantly as well with the largest tress able to provide a wide shaded area in big yards.
When it comes displaying the plants indoors and in your garden, there are a few species you can depend on.
- Blooming grevilleas are perfect if you want a lot of lovely flowers and different colors. You’ll find all sorts of colors from different species, including orange, yellow, pink and white just to name a few.
- Foliage grevilleas are likewise a great option if you prefer a more “leafy” look as opposed to flowers. Here, you also get to pick from a good range of colors. Many come with dark green leaves. But, you’ll also find those with medium to light green as well as yellow green foliage.
- Needled foliage grevillea are perfect if you want to add texture and a unique look to your garden or an area. They are unique looking and have wide leaves
- Grevilleas with broad leaves are likewise perfect when you don’t want a lot of flash but still want a light touch or nature.
- Large tree varieties are perfect as shade or to break winds. They also work well if you want to populate a large plot of land.
- Grevillea shrubs grow tall and thick. This makes them perfect for blocking out nosy neighbors or to add privacy to your backyard.
- Smaller more compact varieties are likewise available. These are better suited for container gardens, be it indoors, in your patio or deck.
These are just some ways to use grevilleas in your home and garden.
Grevillea Plant Care
Because of their variety, the lighting preferences of Grevilleas can vary. But, are a group there are some similarities. They all like the sun.
More so, if you take them by plant types, you’ll see that similar Grevilleas plants enjoy certain kinds of lighting conditions.
For example, outdoor varieties (which also happen to be larger) including trees and shrubs do best under full sun. These plants like to get at least 8 hours of sunlight every day to be healthy. Without it you’ll see them lose their vibrancy, especially the colorful ones.
That said, they will also tolerate a bit of shade. This isn’t feasible for some of the larger Grevillea tree species because of their size. But, shrubs and other varieties won’t have issues when placed under the shade of a tree, patio or canopy as long as they still get a lot of bright light.
Indoors, you will need to find a spot where they will be able to receive bright light as well. This means you get the option of choosing between a south-, west- or east-facing window.
- South facing windows are the best place to grow your Grevillea houseplant. It supplies them with a lot of sunlight throughout the day. And, they’re not afraid of direct sunlight as well.
- West facing windows come next. These are great because afternoons are longer than mornings. And, the intensity of the sunlight is stronger from noon all the way to mid-afternoon.
- East facing windows work just as well. It is often the best spot for houseplants that prefer bright, indirect light. But, that’s not an issue here since Grevilleas actually like being placed in the path of the sun’s rays.
The one place you don’t want to put them is in low light areas or dark spots. This is where they’ll struggle.
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Grevillea Plant Temperature & Humidity
Grevilleas thrive in warm weather. They are native to Australia and some areas of Southeast Asia. Both of which experience warm to very hot temperatures most times of the year.
Thus, these plants do best in the warmer USDA zones (10 to 12). They also like long growing seasons because their native environments provide them with sunlight all year round.
It is also worth noting that these plants are often found in tropical regions and rainforests. As such, even if a few areas in Australia experience snow, these are up the in the mountain and higher up lands, which are far from where Grevilleas grow.
So, as a group, they are used to warm and humid conditions that experience some rainfall.
This means if you live in cooler climates or areas where it snows, you’ll need to grow them as houseplants. Another option would be to place them where they are protected from the elements. This includes greenhouses or spaces that have some kind of cover or protection from the frost like a shed or garage.
Because they are used to warm areas they have adapted to surviving without a lot of water. This makes them very low maintenance in terms of watering requirements.
Grevilleas are drought tolerant. So, you have the luxury of placing them where you want and forgetting them for a little while. In fact, they do better when you don’t water them regularly. During the warm weather and hot summers, once a week is more than enough.
That said, the worst thing you can do for these plants is overwater them. They are very susceptible to too much water and easily damaged by root rot.
As such, it is important to only water them when the soil is dry. And, you’ll always want to be aware of how much rainfall there has been in recent days. This way, you can avoid “doubling” the water on some days.
The only exception to all these rules is for young Grevilleas. These need a lot of water during their growing season, at least until they get established. Once they’ve reached that point, it’s time to scale back watering significantly.
From above, you can probably already tell that the plant prefers very well-draining soil. Here, you can use either a succulent or cacti mix. Either will work very well because both are designed for plants that also don’t to sit in moisture.
However, you are not limited to these two kinds of soil. In fact, Grevillea plants aren’t too picky when it comes to soil. And, they’ll easily adapt to what you give them. They also don’t have a problem with poor soil or pH.
The only one rule with soil is that is must drain water well. As such, if you decide to grow your Grevillea in a container, make sure that the pot has a few holes at the bottom to allow the excess moisture to drain.
As with soil, Grevillea plants are not too fussy as well. This allows to you use different kinds of fertilizer for it.
But, again, there is one basic rule: No high phosphorus fertilizers. These plants cannot tolerate too much of this element. So, if you do pick a plant food for your Grevillea, make sure to get one that is low in phosphorus or doesn’t contain phosphorus at all.
Alternatively, you can likewise go with no fertilizer, which works from some varieties.
Pruning Grevillea Plant
Grevilleas require regular pruning. This keeps them from getting messy looking. It also lets you shape them the way you want. Trimming the plant likewise lets you control its size. In addition, this encourages new growth which will allow your plant to flower even more.
With this plant, you don’t have to be overly gentle or careful when it comes to cutting it back. Because they grow fairly big and bushy, you can prune anywhere from 1/3 to 1/2 of the plant in one session.
While you’re at it, make sure to remove all the dead, dying and old flowers as well. This will allow the plant focus its energies to the fresh and healthy flowers.
Grevillea Plant Propagation
Propagating Grevilleas varies significantly depending of the variety of the plant. Some are easier while others like the Grevillea Long John are very difficult to do so. As such, while it is the most popular variety of Grevillea, it is also fairly rare.
That said, most of these plants are propagated by cuttings or seed.
Transplanting & Repotting Grevillea Plant
As a group, Grevilleas are fast growing. This, along with their beautiful flowers, low maintenance and toughness make them very attractive plants to grow.
But, it also means more pruning (see above) and repotting, if you happen to grow them in containers. Younger plants will likewise need to be repotting more often because of the growth spurts. But, in general, expect to move your Grevillea more often than not.
When you do repot them, almost make sure to use containers that have holes in the bottom. This helps prevent overwater. You can likewise use clay or terra cotta pots which are made from porous material. Thus, they allow some water to seep out over time.
Similarly, many of them grow fairly big in size and breadth. As such, if you plant them in your garden, make sure to provide enough space between plants.
As beautiful as many of these plants look, you always want to check their background before touching them. That’s because a good number of Grevilleas can cause allergies and irritation to skin. Additionally, some are outright toxic.
Thus, it’s not a good idea to grow Grevilleas where kids, pets or even adults can just inadvertently touch them.
Pests and Diseases
One of the reasons these plants are low maintenance ins that they are disease and pest free. In fact, they rarely have problems because they’ve grown to be tough due to their native conditions.
Similarly, the few insects they attract are often fended off or eliminated by birds and other pollinators which are attracted to these plants because of their nectar.
That said, overwatering can still be a major problem, leading to root rot which the plant is very susceptible to.