Talking purely in terms of aesthetics, yellow gardenia leaves look pretty sweet.
They can add that hint of fall to your pictures and brighten up your mood like fall usually does.
However, this does not mean the yellowing of gardenia leaves is normal, and, in fact, it may even be a cause of concern!
So, Why Exactly Are Your Gardenia Leaves Turning Yellow?
If you search the internet for reasons behind something as minor as a mild cough, it will come back with a bold claim like cancer.
But, not all coughing is linked with cancer, right?
The same goes with yellow gardenia leaves and people claiming it’s apparently only a “lack of fertilizer” that triggers the yellowing. In reality, it could be more than that – perhaps a reason much simpler?
1 – Temperature Changes
Yes, you read that right! Temperature change can absolutely affect your gardenia plant on both an aesthetic and cellular level!
Even the shortest periods of cool breezes can turn the greenest gardenia leaves yellow. If summer is coming to an end and winter is slowly setting in, your gardenia leaves are more than likely to turn yellow or even brown.
There’s obviously no particular solution to this issue since you can’t really control overall temperature change, but what you can do is perhaps get them some extra sun exposure during the daytime.
2 – Iron Deficiency
Though it’s rare to find soil that has insufficient amounts of iron in it, soil with a higher PH may contain iron but often in a form that isn’t useful to the plant.
Therefore, the plant isn’t able to produce enough chlorophyll – a pigment that gives the leaves their crisp green color.
A simple solution for iron deficiency in plants is to use an acidic nitrogen fertilizer.
3 – Spreading Disease
If the yellowing of gardenia leaves is accompanied by strange shapes, patterns, or holes in the leaves then a disease is likely to blame.
Fungus, bacteria, and rot may infest the plant leaving it weak and vulnerable. Be on the lookout for pests like mites and whiteflies as well. They can attack in great numbers and bring down a whole gardenia plant in no time!
While fungus can be prevented by using a well-draining pot, fungicides, and pest control can further help by fixing the issue at the root.
4 – Too Much Or Too Little Hydration
Both underwatering and overwatering a gardenia plant can trigger the yellowing of the leaves.
Expert gardeners suggest only watering enough to keep the soil moist but not create a puddle. Underwatering has its own downsides including dryness and stripping away of color from the leaves.
Both extremes must be avoided for the best longevity of your gardenia plant.
Make This Homemade Mixture!
I usually use a very simple “magic” mixture that my mother taught me that usually works, the gardenia leaves (and not only that, it also works with tomato plants, cucumber plants, etc) usually become green again, beautiful and healthy in just a few days.
You will only need:
In 5 liters of water I add 1 liter of milk and 1 tablespoon of soap (used for washing dishes). I apply the mixture to the leaves with a sprayer two days in a row, just once a day, and wait.
In about 5 to 10 days, the leaves turn green again (the soap serves to “fix” the mixture to the leaves, it will not harm them).
Almost done…
Though gardenia plants look quite eye-catching and aesthetic when yellow, it doesn’t mean they’re in their best state.
They could be in all sorts of trouble including a pest attack, disease, severe nutrient deficiency, and whatnot.
It’s important to keep an eye on yellowing leaves and take urgent action if the issue seems to be deeper than a minor temperature change.
