Q. I want to grow gardenias. I live in the desert, and wondering what is the best soil and where I should plant gardenias in the yard? How much son do they need? Do they need to be kept in pots or planted in the ground?
A. There are pluses and minuses when keeping gardenias in pots or containers; in some ways containers make growing gardenias easier and, in some ways, more difficult. But first things first.
Gardenias are not desert plants. The reality is, if you want to grow gardenias in the desert then they will cost more to maintain and take more time to properly care for them. They are native to tropical and semi tropical parts of the world that are non-desert. This means to grow them successfully, we need to try to emulate their native growing conditions as closely as possible. If you agree with that plan, then let’s get them planted!
They need light for flowering but too much light will damage them because of the intensity of our desert sun. But planting them in too much shade will cause them to grow but not flower much. If it's way too much shade, they won't flower at all!
Typically, growing them on the east or north sides of a home, so they are shaded from the intense afternoon sunlight, will work.
The soil where they are planted should be amended so it is close to the soils in parts of Africa and Asia where they are native. This means amend or mix into the soil a good quality compost when planting. Dig the planting hole at least 3 times the diameter of the store-bought container. The hole doesn’t have to be deep, just wide because plant roots grow horizontally where the fertilizer is applied.
Don’t cover the soil around them with rock. Use a 3-inch depth of woodchips so that it decomposes into the soil and continue to improve it as it decomposes.
Potted or not?
The good thing about containers is they can be moved to a different location if the first location is not the best. They can be moved into the garage if freezing temperatures are extreme. They can take temperatures down to 15° F. They are semi tropical plants so freezing could be a problem some extreme winters!
Secondly, container soils are isolated from bad landscape soils and can be amended much easier than landscape soils. But container plants require more upkeep. Every couple of years the plant should be removed from the container, the roots cut and the whole plant repotted with fresh soil.
Organic fertilizers such as compost are best but mineral fertilizers could be used if the soil is covered in decomposing woodchips. A single application of compost or a mineral fertilizer in mid-February is enough for general care but if these are your “pride and joy” then lightly fertilize these plants 3 or 4 times a year with a rose fertilizer.
To help prevent yellowing of the leaves during the growing season, add an iron fertilizer to the soil along with your first fertilizer application.