Question
QUESTION: Hi Jim,
We planted several mature (between 15 and 21 feet tall) maple and birch trees; we purchased them from a nursery and installed them between last October and December (mild winter). All were doing pretty good until recently the leaves on the maples are droppy and there are spots on the leaves (looks like rust), and the birches worry us because there are a lot of branches but not so many leaves -- and many of the leaves are yellow.  

We never had problems with planting of smaller ( < 8ft) trees and we're concerned that we did something wrong with the more mature trees.
Can you please help?
Thanks


ANSWER: They do not have much of a root system to pick up water. The best thing you can do is make sure they have plenty of water. A tree needs at least 1 inch of water per week. Place a pan under the tres and turn the sprinkler on and when the pan has 1 inch of water in it stop. I would do this every third day for a couple of weeks to insure water is getting to the roots. If it rains this is not necessary. If you have not done so mulch around the trees with an organic mulch not moe than 3 inches deep and not piled up on the trunk. This will help hold moisture.

---------- FOLLOW-UP ----------

QUESTION: Hi Jim,Thank you for the answer,
How long will it take for these trees to get a good root system established (re-established). And would you recommend any ferterlizer?
Thank you,
Mirella

Answer
It will take at least a year (a growing season) You will more than likely get some die back --the roots system will need to grow large enough to support the amount of foliage. The roots supply moisture and food to the leaves to make them grow in turn the leaves manufacture food that is transported to the roots making them grow. On newly planted trees the leaves will bud out but the root system may not be large enough to furnish the amounts of water and food that the foliage need to keep growing so the foliage will die back to the point that the roots can balance the supply (die back of some limbs will occur). Sounds like what is happening here and the roots need help with water.