Can you possibly tell me why the leaves on a Purple Plum tree I have might be turning green? The tree did receive some leaf damage from insects - I have sprayed for that. I water the tree twice weekly. We are in an area that has been in a drought since the spring and have received rain only about every other week. Thank you.

Reply to post by Shirl M, on July 24, 2002 at 07:21:34:

I have some questions.
Did all the leaves start as purple and turn green?
Did all the leaves just begin as green this season?
Are there new leaves that are green and older leaves that are purple?
Is this a fruiting plum with purple leaves?
What is the variety name?
Where does this tree live?
How long has the tree been there?
When did you start watering the plant, since the drought began?
Are the leaves damaged in any way?

Some varieties of plum are less purple in the leaf than others.
A flush of growth might begin green and darken to purple later.

Reply to post by Mark Goodwin, on July 24, 2002 at 07:21:34:

All the leaves started as purple and are fading to green. I just planted the tree in the spring and the newer leaves are coming in purple. It is a Newport Purple Leaf Flowering Plum and is planted in a sunny location in Maryland. I watered the tree every 2 to 3 days for the first 2 weeks and then twice a week since then - we have been in a drought since the spring. The leaves have holes in them from insects - I have sprayed the tree for insects.

Reply to post by Shirl M, on July 25, 2002 at 11:36:45:

I have to admit I am guessing at this point.
Sometimes insect damage can cause color change in leaves.
What insect was the target of your pesticide, and what pesticide did you apply?
Leaf color is influenced by various pigments, including chlorophylls and carotenoids (which work in photosynthesis), and anthocyanins.
Perhaps the pigments affecting purple coloration were damaged in some way, selectively leaving the chlorophylls?

Another thought: I have seen some trees with purple coloration shift toward green when they encounter insufficient light.
Anthocyanins (if I recall correctly) help plants to adapt to intense light exposure. Often, new growth is anthocyanin-rich.
But you say the tree is in a sunny location.

Also, the fact that your tree has suffered severe insect attack may point to a lack of vigor.

Reply to post by Shirl M, on July 24, 2002 at 07:21:34:

Your tree problem has bothered me. When a similar post came in, I began to wonder about your irrigation practices toward your tree.

General statements about frequency of watering can be misleading. What is important to know is:
How much water is in the root zone?
Is soil water draining quickly enough through the root zone to prevent saturation for long periods?

Too much water depends on soil drainage properties, as well as quantity and rate of application. Consider whether it is possible you may be over-saturating the soil and that it may not be draining properly.

I have included a link which deals with garden irrigation principles. While it is designed for another area of the country, it should still offer some valuable basic information.