A native Australian flowering plant, Banksia thrives throughout the country. They are drought-tolerant, attractive, and versatile, with flowers that will continuously bloom. They are particularly useful for landscaping, as they can grow into 6 to 12 foot shrubs, and can even be 30 to 60 feet in size as full-size trees. Banksia requires a few things to really grow: sunlight, well-drained soil, and good air circulation.
The Banksia Plant
Banksia are known for their brilliant, small flowers that bloom throughout the year, and are either round or cylindrical. They can come in a variety of colours: cream, red, yellow, brown, orange, and green.
When choosing your banksia, you will make the choice based primarily on the colour of the flower and the size of the banksia. Because banksia can span from 6 foot shrubs to 60 foot trees, it’s important to know what variety you’re getting before you plant them.
Planting Your Banksia
Start by finding a place with a lot of sunshine. Banksia requires a lot of sun, and the warmth also keeps it from becoming too moist. Because banksia is a dry, drought-tolerant plant, too much moisture can easily cause damage. Plant your banksia about four meters away from any water lines if it’s a large banksia, otherwise, you could experience some disruption due to the roots.
Dig a hole that is twice as wide as the banksia plant’s root ball and the same depth as the ball. Place the banksia in the hole and then separate the roots gently and position it spread out into the soil. Backfill gently and then water thoroughly; the water will also help the soil settle. If you have clay soil or heavy soil, you can also consider using a raised bed. A raised bed will lift the banksia up well enough to drain it.
Placing mulch around the base of the banksia will help it keep moisture, but it’s important that it still be in a warm location and drain well. Water twice a week until it has established itself.
Your banksia plants will flower regularly and will continue to develop as it grows. For the first year or two, it may start to establish itself. After that, it will become hardier. Because banksia doesn’t have a main taproot, it does take them some time to establish themselves, but once they do establish, they should quickly start to flourish.
You can also grow banksia in a container as well. The container should be large enough for the banksia to grow into, so about one and a half times the size of its root ball. You can still add mulch; plants in containers will dry out much faster than plants outside of containers.
Caring for Your Banksia
Water your banksia regularly at first, and then cut it back to develop its drought tolerance. Add fertiliser in autumn and spring if needed for the first couple of years.
As long as the conditions are right, your banksia shouldn’t require much by way of care. You can fertilize your banksia every year or two after the initial growth, but you should make sure that your fertilizer doesn’t have too much phosphorous because phosphorous can kill banksia.
Additionally, while you don’t need to prune your banksia, you can if you want to. When pruning your banksia, you should avoid cutting into any of the old-growth, and instead cut only the new growth back. Prune frequently if you want to control the banksia, so you don’t need to cut it back significantly at any one time.
You can prune spent flower heads to keep the banksia looking well-kept. This isn’t necessary for general health, just for appearances!
Common Problems With Banksia
Banksia is generally a fairly low maintenance plant, but there are some issues that can occur, depending on the type of banksia that you’ve planted, your environment, and your garden. Here are some of the most common issues.
- Root rot. Root rot is one of the major killers of banksia. Because it is a drought-tolerant, warm weather plant, it can easily become damaged if it’s exposed to too much water. You will see the plant wilting and the leaves may turn brown. You can confuse root rot with a lack of water and then begin overwatering the plant, which will only exacerbate the problem. You will need to start improving soil drainage and may need to cut back on watering. It’s best to water very deeply but infrequently. If the root rot takes hold, it will be necessary to remove the entire plant and start again.
- Phosphorous toxicity. The reason you don’t want to fertilise banksia too often is because it can kill it! High levels of phosphorous will end in yellow, damaged leaves, and eventually the plant itself may die. To keep your banksia healthy, only use low phosphorous fertiliser, and do not fertilise too frequently. Even banksia that needs nutrients should be fertilised only twice a year. Further, you may only see symptoms of fertiliser toxicity about twelve months after the fertiliser has been placed, so you should keep it on your mind. Phosphorous toxicity can also be difficult to deal with, as the fertiliser will stay in the soil.
- Caterpillars. Of all pests, caterpillars tend to be most drawn to banksia. Of course, if you love butterflies, you may be drawn to the caterpillars too. Caterpillars can be dissuaded by something like eco-neem safely. The way to tell if you have caterpillars is easy: you’ll see them munching down on the leaves, and you’ll see the sections that have been taken out of individual leaves.
On a whole, though, there’s little that tends to affect banksia. These large, elegant shrubs and trees are a great addition to any yard, and are a way to brighten a home or a business. Once they have properly established themselves, it’s difficult to deter banksia, and you can find them in different sizes, with a wide variety of blooms.