Gardenias Need Special Location and Special Treatment in the Desert

Q. Can you determine what is going on with the gardenias? Why the red spots on the leaves?

A. I looked at the pictures. If you look at the leaves that are not turning brown or red yet you can see the beginnings of interveinal chlorosis or yellowing between the veins. This is because of high soil pH and alkalinity which is making iron not available to the Gardenia.

This might also be a sun issue. They cannot be planted in full sun here or afternoon sun. Keep them on the East or north side with lots of indirect (reflected) light.

Gardenias also do not belong in the desert. I'm not saying you can't grow them here but just like magnolia you've got to do things that are similar. Gardenia is even more sensitive to alkalinity in the soil and high pH than the magnolia.

You will need to lower the soil pH and at the same time add iron in a form available to it. Get iron EDDHA chelate. Get a good quality fertilizer that has an acidic reaction with the soil and stay away from fertilizers that promote alkalinity in the 

soil. Making sure the plant has adequate nutrition will make them healthier and better able to handle heat and direct sunlight.

A good product to use with the iron chelate I am suggesting is another product that Viragrow is carrying called Maxi Plex or you could use Soil Acidifier by Grow More.

I have checked prices against prices on the Internet and on most products they either beat those prices or very similar. Feel comfortable about sending people and the prices they charge.

Just like magnolia, gardenias need soil amendments at the time of planting and organic mulches on the surface to help lower that soil pH. You can use sulfur but the compost will be more effective in lowering soil pH than the sulfur and a lot easier to work with.

Gardenias should never be on the South or West side. They need the cooler microclimates of the East and North. They perform better in containers than planted in the ground because they are easier to manipulate.

Viragrow Delivers!