Mulch Can Create Problems for Peach Trees

Q. I bought a Babcock peach in the summer of 2014 and planted it at about an elevation of 3700 feet. I planted it as you recommended including a 4 inch layer of mulch on top of the soil around the tree. The tree budded nicely but I noticed most stem ends just died and dried up this past winter.

Two-year-old Babcock peach

Dieback on Babcock peach stems from a lack of water

A. When stems die back like you describe it is usually a problem with water or freezing temperatures. Unless temperatures dropped down to 15° F it is most likely water related.

            Water related can mean either too much or too little water because both can result in stems dying back. It is obvious that a lack of water can cause something like this but less obvious if it is from too much applied water .

            Giving a plant too much water can mean either two things; either applying too much water each time you irrigate or giving the plant water too frequently. The first one, applying too much water each time you irrigate, usually doesn’t create a problem for the plant, it just wastes water. But the second one, watering too often, can be far more dangerous to a plant.

Collar rot or crown rot on honeysuckle because of wet mulch in contact with the stems

            Watering too often can fill the soil around the roots with so much water that the roots cannot “breathe” and they begin to suffocate. Allowing the water enough time to drain from around the roots allows air to enter the soil again and roots can breathe.

            Unless a plant is growing in pure sand or in a small container, withholding water for a few days before the next irrigation gives roots a chance to “breathe” again. There is enough water left in the soil to last a few days after an irrigation in normal soils.

Apple growing in wet soils with collar rot

            There is another possibility. You mentioned you have a 4 inch layer of mulch on top of the soil surrounding the tree. This will really help your trees, however do not allow this mulch to rest against the trunk of new trees. Always keep mulch away from the trunk of trees while they are young. At least 12 inches.

Wet mulch can “rot” the trunk where it is in contact with the wet mulch. This “rot” is a disease called collar rot. Collar rot disease will “choke” the trunk and prevent water from moving from the roots to the top of the tree. The symptoms are identical to a lack of water and this is a strong possibility in your case.