Leaves dropping on Transplanted Tree


Posted by Horticulture Guy - Peter Punzi | Posted in Gardening Q & A, Northwest U.S. Gardeners | Posted on 02-08-2013

Q. Two weeks ago we planted two 5-6″ caliper, 14′ Thundercloud Plums. We dug very wide holes, dug as deep as the root ball, cut off all the burlap, refilled the dirt with 1/3 organic compost to 2/3 original soil, stamped and watered down the replacement soil, and covered with 3″ bark mulch. Two weeks later both trees are dropping leaves. We thoroughly watered them the first week and now water them every two days. Are they suffering from shock? What are your thoughts of the next step I can take to get them healthy? SMRussell – Bothell, WA

A. Dropping leaves is how trees cope with stress. Many tropical trees drop leaves for the dry season and temperate zone trees for winter.   Mid summer is always a tough time to transplant large trees. When possible plant them in the spring or fall.  There are many stress that can cause the leaves to drop as the fine hairlike root structures responsible for water uptake are often damaged. Trees compensate by dropping leaves thereby reducing water loss from the leaves (evapo-transpiration).    Loss of leaves does not mean the plants will die though.  One concern is to make sure you do not over water.  If you have not done so make sure your soil is well draining. If you dig a hole for a tree in a very clay soil it can become like a container that fills up with water and then rots the roots.  Of course rotting roots have the same symptoms as dry roots because the plant can’t take up enough water.  Do a perc (short for percolation) test.  Here is how: http://www.horticultureguy.com/television-segments/testing-soil-drainage/

If your soil is not well draining make sure you test it for moisture before re-watering.  Also for future reference current tree planting does not recommend amending the fill soil.  It is now believed that this may encourage the roots to stay inside the dug area and not move readily into the surrounding soil. – HG