Asked September 21, 2019, 6:29 PM EDT

Hello, I am having some problems with a potted gardenia plant. Two month ago the leaves were turning yellow and I was recommended to fertilize it with MiracleGro for acid-loving plants and iron sulfate. I did that and also moved it to a bigger pot. Now, around 2 weeks ago I started noticing the leaves are brown and dried. I stop the acid fertilizing but the plant is not improving. Any idea what this can be and how can I solve the problem. All help appreciated!!! Thanks in advance.

Montgomery County Maryland

1 Response

Your gardenia is very stressed.
Even under the best circumstances growing gardenias is challenge in our area. The special training needed to make this grow in a tree form and repotting only adds to the stress. Trying to keep them happy indoors for the winter is not easy.
They generally like to be pot bound and don't need repotting unless the roots are appearing above the soil or growing heartily out of the bottom of the pot.

We can't tell from your photos how far along the decline is for your plant. If it's important to you and you want a year-round project to try to keep it healthy and happy we can go over their needs and preferences.
If it was just a spring/summer interest, we think it may be time to let it go.

First off, we are assuming that there is a drainage hole in that pot?
How often were you fertilizing? Every two weeks during the growing season is recommended. How much iron sulfate were you using?
How often were you watering? The soil mix needs to stay moist during spring through fall, watering freely until water comes out of the bottom of the pot, and watering again when the top half inch is dry. The pot should not sit in a saucer of water but on top of a layer of moist pebbles to increase humidity. In winter indoors they 'rest' and don't need as much water; only enough so that the soil mix does not completely dry out.
Was it being kept indoors or out?
We don't see signs of insect pests or disease right now, so we think the problems are abiotic or environmental/cultural in origin. Abiotic injury may be caused by drought or excess water, exposure to low light or extremely sunny conditions, or may be associated with poor planting media. Overwatering is the number one reason why houseplants fail.
Gardenias need bright light, but not direct sunlight. The brightest spot you can give them for the winter is best. Bring it inside before night temperatures reach the mid-to low 50's. If it is happy and viable, you should see some small signs of sprouting along the branches in time.