Follow-Up Questions on Peach and Citrus

Q. A few months ago you told me how to help my grapes and other fruit trees (thanks for featuring my yard on the blog)! My citrus is turning black and dropping. The main issue I am having now is my peaches are turning a dull yellow, almost like a brown but not really. The photos don't really catch it. I dug about 1 foot away from the plant to see if the soil was too damp and found that it was moist about 3-4 inches below. With the last watering cycle happening about 3 days prior. The plants get 5 gallons in the morning and 5 at night.  2 times a week. I did put some of "stress tonic" and a little iron just in case, but far less than the recommended amount.

Readers peach tree

As far as my tomatoes go, most of them are done or dying but produced heavily so I am pleased. I had a few watermelon which were quite tasty and they may reproduce again. My citrus are having a bit of a rough time most of the fruit turned black and fell off (in containers and get a few hours of partial sun.) although the plants are shooting new growth and even flowered again. Although this time not fruiting.

Any advice or thoughts? Also should I prune them back any?

A. Fruit dropping can be a sign that your citrus may be going through excessively dry periods before they are irrigated again. It can also be a sign that your trees are just too young to support fruit development yet and so the fruit was aborted. Citrus leaves can discolor, turn kind of a bronzy yellow, due to damage from the sun. You won't see as much of this if they are growing in the ground and the surface of the soil covered in wood chip mulch. You can use an inexpensive houseplant moisture meter to get a very general idea what the moisture level of your soil is. Stick it in several locations so you get an idea of how the water is distributed.

All fruit trees need at least six hours of full sun each day to produce an adequate amount of fruit. Roots of fruit trees growing in containers have the largest percentage of the roots that take up water and nutrients in the boundary area between the root ball and the container. This is also where the drying of the root ball occurs first. And containers exposed to direct sunlight will overheat the root ball on any side that is in full sun unless it is protected. You could lose as much as 50% of your root system if that root ball overheats from direct sunlight on the container.

I looked at all of your pictures. All of the growth that I saw looked good for this time of the year. There was a lot of leaf cupping on your peach which can be due to heat. It was showing some signs of some water stress. This can be the scorching on the edges of leaves. 

I did not see wood mulch on the soil beneath the trees. Your fruit trees would benefit 1000% if you can apply a layer of wood chip mulch, not bark mulch, on the soil surrounding the tree in a circle about 6 foot in diameter. The mulch should be 3 to 4 inches deep.

This was an unusually good year for tomatoes. Don't expect this type of production every year. When the spring months jump from cool to hot very quickly, tomatoes will not produce as well. Tomatoes produce much better if they are protected from excessive wind. You can do this by deflecting the wind away from the garden or putting up windbreaks.

Fruit trees do quite nicely with one or two applications of fertilizer year. This is usually in the late winter and perhaps a second application after harvesting. I tell people to fertilize their vegetables and herbs monthly.