Can I use regular garden fertilizer?

No, you must use a fertilizer labeled for Australian natives. Banksias are sensitive to phosphorus and can be harmed by standard fertilizers.

Should I prune yellow leaves?

You can remove them for aesthetic reasons, but they will likely fall off on their own. Focus on fixing the underlying soil issue instead.

Coast Banksia: yellow leaves, causes and fixes

Check these first

Check the soil moisture two inches below the surface.
Inspect the area for standing water after rain.
Test the soil pH to ensure it is acidic enough.

Likely causes

Poor Drainage
Most likely
How to tell: The soil stays soggy for days after watering and the leaves turn a pale, sickly yellow. This often leads to root issues if left unaddressed.
What to do: Improve the soil structure by adding organic matter or grit to increase aeration. Ensure your planting site is on a slight slope or raised mound to help water drain away from the roots.
Iron Deficiency
Possible
How to tell: The veins of the leaves stay green while the rest of the leaf turns yellow. This happens when the soil pH is too high for the plant to absorb nutrients.
What to do: Apply a phosphorus free fertilizer specifically formulated for native plants. You can also lower the soil pH by adding elemental sulfur if a soil test confirms it is too alkaline.

Yellow leaves on other plants

Find out what's wrong with your coast banksia

The list above covers the usual causes. Pocket Botanist looks at a photo of your actual plant and tells you the likely cause, how serious it is, and what to try first. Identification and a health check are free.

When to worry

It is normal for the oldest leaves near the trunk to yellow and drop as the tree grows. Worry if the yellowing is spreading rapidly across new growth.

Stopping it coming back

Plant your Banksia in well draining, sandy soil and avoid overwatering once the tree is established.

Coast Banksia: yellow leaves? Check yours with a photo

Every plant is a little different. Take a photo of your coast banksia and Pocket Botanist tells you which cause is most likely, how serious it is, and what to try first. A few checks a day are free. Save the plant and you get care reminders timed for it.

Get the app · Or check it from a photo now, free

Questions people ask

Can I use regular garden fertilizer?: No, you must use a fertilizer labeled for Australian natives. Banksias are sensitive to phosphorus and can be harmed by standard fertilizers.
Should I prune yellow leaves?: You can remove them for aesthetic reasons, but they will likely fall off on their own. Focus on fixing the underlying soil issue instead.

Guides to these causes

Chlorosis

Why are my Coast Banksia leaves turning yellow?

Check these first

Not sure what's wrong with your coast banksia?