With its striking allure, the Banksia Spinulosa - more commonly known as the hairpin banksia or bush candles - is an easy-to-care-for, utterly gorgeous plant that is a go-to for any home gardener.
This gorgeous evergreen, perennial is an ideal option for rocky, drought resistant gardens and can even be grown in a pot. They are a gorgeous addition that will add texture and touch of wildlife to your backyard.
Ready to get planting? Great! It’s easier than you may think. From propagation to daily care- as well as tips and tricks you’ll need along the way, here’s everything you’ll need to know for your Banksia Spinulosa growing journey.
What is Banksia Spinulosa?
Best recognized by its flowers, the Banksia Spinulosa, is an eye-catching variety of the proteacae family. Its flowers, which form oval-cylindrical clusters at the ends of its stem, bloom into a variety of reds, oranges and golds.
Similar to Banksia serrata originating from Australia (find out more about Banksia serrata here), the hairpin banksia is considered to be a medium sized (6 to 12 foot) shrub, growing to as large as 30 to 60 feet.
However, dwarf varieties have also been found around coastal areas in Australia, like New South Wales. Dwarf varieties have cultivated nicknames like ‘stumpy gold’, ‘coastal cushion’, ‘honey pots’ or ‘birthday candles.’
The Banksia species was in fact named in commemoration of the famous botanist Sir Joseph Banks who had travelled extensively with Captain Cook.
Spinulosa refers to the long, narrow, spindle-like leaves that it possesses. These leaves are about 1 to 3 inches long. The banksia has the ability to grow in both warmer and cooler climates, is rather frost tolerant but does not do well in highly humid environments.
Did you know that the banksia species can live up to 100 years? That 100 years of vibrance in your backyard. The plant also produces a nutrient rich pollen, which attracts bees, butterflies and birds. As such, banksias are considered great pollinators and very beneficial to your local ecosystems.
Did you know that Empress Josephine, the wife of Napoleon Bonaparte, had cultivated many Banksia varieties for the garden at Malmaison in Paris? Their allure truly has stretched the seas.
How to Grow Banksia Spinulosa
Picking a spot to plant your banksia is easy, it is quite tolerant of most soils and as such happy to be planted either in the ground or in a pot.
The spinulosa creates an enticing dramatic effect in your garden, when planted all together - but is also a great eye-catching element when smaller groups are placed around your garden.
The most important factors to consider are that it grows in a place with full sunlight, good air circulation and has well-draining soil. Banksia have special, proteoid roots that enable it to grow in low-nutrient soils.
This means your plant will require very little fertilizer. When re-planting your banksia, place root stock on a low mound of soil, then fill the rest of the hole with a gravel mulch.
This will promote better drainage, which your plant will rely on. They are not particularly acidic or alkaline sensitive. It is important to note that the banksia is, however, quite sensitive to phosphorous.
If your soil is clay based, add generous amounts of bark or compost to your soil before planting. Here are steps on how to improve clay soil.
Banksia Spinulosa Propagation
Again, the hairpin banksia is a fairly low fuss plant. It can be propagated from seeds and cuttings. The seed-route is likely the easier option as the majority of banksia seeds remain viable and germinate easily.
Growing Banksia Spinulosa from Seeds
- Seeds germinate 14 to 60 days after sewing.
- Ensure the soil in which your seed is planted, remains moist. You can do this by means of a mister.
- Try refrain from leaving the soil too wet, however.
Propagating Hairpin Banksia from Cuttings
- This is a slightly harder option.
- The cutting should be taken in late spring.
- Cuttings, from about a half an inch in length should work.
- Be sure to remove all leaves.
Caring for Banksia Spinulosa
It is a drought tolerant plant and really does require very little attention, especially if it’s planted outdoors. It’s a whole lot of aesthetic for largely little work.
You can consider the banksia a some-what slow-growing plant, as it may take a few years to flower. However, once it does, your plant will bloom every late autumn and continues to flower throughout the winter and well into spring.
Once flowered you can remove the cones or leave them to wither creating its own hauntingly beautiful aesthetic. Here’s three things you can do:
Watering Your Banksia
In your banksia’s first year or two, be sure to water it regularly. Thereafter, you won’t need to water your plant that much. After the second year, you can cut back to an occasional good soaking, if it is particularly hot and dry.
If your banksia is living outdoors and receives regular rainfall, be sure it is not over-watered.
Pruning of your plant will be largely unnecessary. Trimming can be done at your own whim and can be used to moderate shape and size. You can trim back dead branches or remove dead flowers if you wish.
Fertilizer Banksia Spinulosa
Should you want to support your plant with a few more minerals, you can always consider adding some natural mulch to your soil. Iron-rich fertilizers are also a good option for the banksia.
However, this may not always be necessary. Just keep an eye on your plant to make sure it stays healthy and happy.
Hairpin Banksia Possible Pest and Diseases
Not really, no. Pests are generally quite rare to find on your banksia. You will perhaps come across the odd caterpillar. Most varieties have a small appetite, rendering them largely harmless.
However, some species like the Grevillea looper are more aggressive in their feeding and can become an issue. Luckily, there are easy ways to naturally get rid of pests in your garden, without harming your plants or the ecosystem.
Other than that, you shouldn’t face many pest issues. You may, of course, be welcoming some lovely, little nectar lovers, like bees, butterflies and even the occasional bird.
If you’re wondering why your banksia is dying, it could be due to a disease. The most common causes of diseases in banksia are inadequate draining soil, issues around phosphorous levels in the soil or a type of fungus.
As with many plants, the banksia is susceptible to root rot, which can pose deadly for your plant. You can recognize root rot when your leaves turn brown and wither but remain on the plant.
To combat this problem, try adding organic material like compost which can rebalance your soil. Learn more about composting and it's benefits here.
Phosphorous poisoning is a real problem for the hairpin banksia, as that is the one element to which it is sensitive. To recognize poisoning, look for yellowed leaves with browned tip edges.
Unfortunately, it can take a while for the poisoning to occur and the plant may not always show signs early on. A seaweed soil care can help neutralize the toxicity. (Refer to this seaweed extract for reference).
Cinnamon Fungus (Dieback)
Dieback is posing a tremendous threat to plant-life in Australia at the moment. Many banksia species are highly susceptible to this fungus, the banksia spinulosa included.
Cinnamon fungus is in fact listed as major threat by the Environment Protection and Biodiversity Conservation Act. As it is a microscopic, soil-borne pathogen, the fungus is easily spread.
There are certain chemical options to prevent dieback. However, you can also consider raised beds, which will restrict the access of contaminants to your soil.
Check out comprehensive guide on how to start a raised garden bed here. So, what more could you need to know? Go out and grow!
Banksia Spinulosa Frequently Asked Questions
How tall does banksia spinulosa grow?
Hairpin banksia can differ in height, flower color and form depending on the growing conditions and the variety grown. In cultivation, it will grow to about 1 to 3 meters tall with flower spikes that range from 10 to 20 centimeters in length.
How do you take care of a banksia hairpin?
The most essential component to caring for this banksia is good soil drainage. This drought-tolerant shrub prefers drier soil over wet and will thrive in well-draining soil.
Apart from that, occasional watering, pruning and fertilizing should ensure you have a happy and healthy plant.
How long do banksias live?
These tough plants can live for over 100 years in optimal conditions.
Are banksias toxic?
This species is regarded as non-toxic to humans and pets.
Wrapping Up Banksia Spinulosa Growing and Caring guide
All you need to do is make sure your Banksia Spinulosa is kept in some well-draining soil and receives heaps of sunshine. Then, you should have a fairly happy, fantastically flowering plant.
With a stunningly extended flowering cycle, you can have the shades of the sunset in your house (almost) all year long. If you live in an area that you know has issues with cinnamon rot, find ways to protect your plants.
The banksia spinulosa, or hairpin spinulosa, really is an effortless plant to grow in your back garden or even in a pot.