Tree not leafing – roots on surface
A year ago we planted a 6 foot tall Samaritan Chinese Dogwood (Cornus kousa Samzam). Our soil is heavy clay so I dug the hole about 6 to 8 inches wider and deeper than the root ball and filled it with "triple-mix" soil. After the tree was planted, I covered the ground with landscaper's cloth in a circular area extending 6 feet from all sides of the trunk, and then placed a hose on top of the cloth and around the trunk. Extending from this hose are 4 smaller hose with a dripper on the end - about 18 inches from the trunk (each of the drippers provide 1 gallon of water per hour, but must be turned on by hand as required. When there has been no rain for an extended period, I turn the tap on for 3 hours every 7 to 10 days). I then covered the entire area with wood mulch. This spring the tree failed to produce any leaves until almost 2 months after they should have appeared - and even then only a couple of dozen leaves have arrived. I checked the branches and they are alive. Today, I removed the mulch and cloth to do a soil test and discovered that a mass of very fine, white roots are on the surface. Based on the above information, could you advise me, in your opinion, if the problem extends to the heavy clay soil beneath the triple-mix or should I be looking for some other cause? Also, although the leaf production is 2 months behind schedule, and limited thus far to only 3 or 4 branches, is it possible that (a) the rest of the leaves could still arrive, (b) if they fail to grow this year, could the tree bounce back to normal next spring or (c) should I just give up on it? Any help/insight you might be able to provide would be very much appreciated. Thank you Ted
Certified GKH Gardening Expert
I think there are a few things in play here.
First the heavy clay soil.
Samaritan Chinese Dogwood grows well in well draining soil. Though you did replace some soil in the planting area the poor draining soil still surrounds the tree.
Next I think the long harsh winter that most of the United States experienced this past winter may have quite a bit to do with the slow wake up and stress the tree is under.
In my research I'm seeing conflicting zone charts for the Samaritan, with some reporting Zone 4 and some Zone 5.
A new planting that was not established may have been greatly effected by the cold.
I personally like to give my trees as much time and chance to grow and catch up. I would really just wait and see.
Thank you for your quick and insightful response. I'll follow your suggestion and give it another 4 to 6 weeks, when the weather is much warmer, to, hopefully, make it through the rest of the year reasonably strong. If so, then we'll begin praying for a milder winter and see what happens next spring.
I'll post the progress in another month or so.