Iron chlorosis on purple leaf plum |
Q. I have two purple leaf plum trees, both about 2 years old. They started the year beautifully. One continues to look normal but the other one has all of a sudden taken a turn that bothers me. The leaves are getting pale and see-through-ish. It is a nice full tree, yet young. Is this as simple as not enough water or something else? It had a great year last year.
A. It is most likely iron chlorosis. On purple leaf plum, an ornamental, the leaves turn a pinkish color and eventually very pale instead of the yellow or light green color with green veins we see in plants with green leaves.
If you want to see if a lack of iron is the problem, then make five liquid applications of an iron chelate to the same leaves, using a spray bottle, several days apart. Add a few drops of Ivory liquid detergent to the spray bottle to improve the penetration of iron through the leaf surface.
Severe chlorosis on fruiting (green leaved) plum |
If it is an iron problem, the leaves will eventually, and progressively with each spray, begin turning their normal dark purple color. It will take several applications with a spray bottle to the same few leaves to make this happen.
Liquid applications to the leaves are not typically as effective as applying it to the soil but you will see the results sooner. One or two applications applied to the leaves will not be enough.
Otherwise, buy some iron chelate containing the EDDHA chelate and apply it to the soil. Do this by dissolving the iron chelate in a bucket of water and wash it in around the roots. You should see a response in the new leaves that come out after the application has been made. This discoloration is also possible if the tree roots are being kept too wet (poor drainage) or if they are damaged.
Hi Robert just wanted to let you know that your advice to use the EDDHA chelate really did the trick on my plum. Should I continue a monthly feeding of the iron chelate?
Also I have another plum that seems like it is thinning. Some of the branches are missing leaves from top to bottom almost. As I drive the streets in sun city and summerlin I see a lot of plum trees that look thin. My tree may have been planted wrong because it is right in a wind gust tunnel it seems in my back yard, but I thought I'd ask in case maybe it is insects or disease.
Usually one application will do it each year. Get it on in February. When they thin like that it is frequently because it is not getting enough water or the soil needs improvement or both. With a fertilizer application in February and iron and wood mulch around the base and enough water you should see a dramatic improvement. It will always struggle if it is in rock mulch. It is possible it is insect,, borers for instance,… but this is usually branch dieback not a general thinning of the tree unless the tree has it real bad.
I have used iron injections as well such as Ace Medicaps. They use iron citrate in the capsules. The problem with injections is tree damage from drilling multiple holes in the trunk. The holes have to be a few inches apart on the trunk to get the iron citrate flowing evenly in the trunk. Holes should never be drilled in a straight line around the trunk. Instead they should be drilled in an upward spiral around the trunk. I haven't used them for years but they used to require a 3/8 wood bit and the plastic housing for the iron citrate capsule was pushed into the trunk so that it was slightly below the cambium and the tree would then heal over the wound. Iron chelates for soil application (EDTA, DTPA, EDDHA, HEDTA all have different pH stability curves…they release iron at different pH's. EDDHA is the ONLY iron chelate that is stable through the entire pH range of 1 to 14. This is why this is the only iron chelate I recommend for alkaline soils and you do not know the soil pH. Yes, sulfur and undecomposed organic matter can lower soil pH but only in warm, moist soils. Sulfur MUST be finely ground for it to work adequately. It is easier to apply the right iron chelate to a soil.
I like iron injections for chlorosis. They tend to last a lot longer (up to two years and are more effective. Mr. xtremehort has some good ideas but i have to disagree with treating the soil with iron. Typically chlorosis is caused by high ph levels in the soil. Iron and manganese are typically in the soil but at the high ph levels it is locked up by the soil and not made available to the tree. Sulfur and organic mater can over time lower the ph levels but for the immediate fix of the tree bypass the soil with an injection.