Gardenia leaves may turn yellow due to different reasons. In this article, I will tell you the most common reasons why gardenia leaves are turning yellow and what you can do to revive them.
Note: Due to multiple reasons for the same issue, you might get confused. Thus, I am gonna tell you how to differentiate them based on symptoms.
I love to grow plants in the ground. But there are a few plants in my garden and on my porch area that I am growing in pots. Leaves yellowing is more common in potted plants.
Major reasons for the yellowing leaves of gardenia
Look at this picture:
My friend got this gardenia two weeks ago. She transplanted it into a terra cotta pot 2 inches bigger than its nursery container last week. She added some soil acidifier and perlite because she knows they like slightly acidic, well-draining soil.
Her heart is BREAKING because it’s already got rapidly yellowing leaves!!
She has been watering daily / every two days to get it established. It’s on a south-facing covered porch, so it doesn’t get any direct sun, but very bright indirect light almost all day.
She’s been pulling it out in the morning to get some morning sun.
Is she trying too hard?? What should she change or do differently? Are the yellowing leaves just transplant shock?
She has a gardenia in her backyard in straight Florida sand that is a decade old and taller than her house… so she thought, “how hard could it be?”
Once you find out the exact reason, you will be able to fix it.
Wrong pot selection and overwatering issue
In her case, it was the wrong pot selection.
I have had better luck with plastic rather than terracotta. The terracotta dried out too quickly for the plants I tried to grow in it. Gardenias are thirsty.
Daily watering in a terra cotta pot can actually lead to inconsistent moisture (too wet then too dry), and gardenias really hate that.
My suggestion to fix this is: Let the top inch of soil dry out a bit before watering again.
Note: Underwatering can also cause yellow leaves. But this time, that will be crispy yellowing. For the overwatering issue, if you touch the leaves or shake the plants, the yellow leaves gonna fall down, and you can witness mushy leaf stalks.
Yes, I am not neglecting the transplanting shock. It’s always better to transplant a plant a few days after bringing it home from the nursery.
Gardenia, in my experience, does not like the root disturbed much during transplant, or it will recover slowly.
This will help your plant to handle the new environment first.
Another major mistake is wrong pot size selection. Make sure you are getting the right pot size for your gardenia plant.
It needs 12–16 inches deep and 5–10 gallon volume pot. (For a mature plant). Reference: Pot size chart for plants
Gardenias are temperamental. Yellow leaves sometimes mean overwatering.
Overwatering is bad for gardenia. But with proper pot depth and size, the chances of root rot decrease significantly.
Inappropriate light exposure
If you notice pale yellowing leaves and weak growth at the same time, it indicates your gardenia needs more sunlight exposure.
Give it bright indirect light and gentle morning sun (upto 4-5 hours max). That's all you need to do.
Too much direct sunlight can cause yellow patches. (especially the afternoon direct sunlight)
So it's easy to identify if the yellow leaves are due to low light or high sunlight.
Some other rare reasons:
If you see the leaves are turning yellow but the veins are still green, it's due to iron deficiency. (Also known as chlorosis)
You can use iron based foliar spray in the evening to fix this.
If everything is alright and you are still seeing those yellow leaves on your gardenia, it's time to check the water quality.
I never considered this to be a valid reason until I found my lucky bamboo leaves yellowing.
Hard water / chlorinated water can slowly cause yellowing.
On Gardenvive, I prefer to share only those gardening issues that I personally experience.
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