New canadian hemlocks dying suddenly

[wysiwyg]

This spring I planted approximately 40 canadian hemlocks from a reputable online/mailorder nursery. They arrived potted and about 6 inches tall. All of them were planted in the best soil in our yard - along existing treelines and in partial to almost full shade - to create a screen among oaks and other trees that had no lower limbs due to previous buckthorn infestation. I gave each one a mychorrizal treatment while planting. Anyways everything was going great. All the trees survived transplant and most of them nearly doubled in size by the end of june. Then about three weeks ago one of them suddenly started to brown and was totally defoliated in about 4 days. A few days ago I found two more that were turning brown and now they are totally defoliated. And yet another one this morning is turning brown and probably on the way out. I have no idea what is going on. The soil is thick topsoil that drains well but doesn't dry out too quick since its in a low area and shaded. I've watered them twice this year, most recently just before the 95F mini heat wave that hit last week. The trees are caged with hardware cloth so I don't think its an animal problem. I haven't given them any fertilzer since they were doing fine without it. Any ideas?

 

[Rtom45]

Unless you have gotten more rain in your area than we have in ours, I would say the problem is lack of water. If it doesn't rain, and especially if it is very hot, I'd be watering them at the very least, once a week.

 

[wysiwyg]

Up until a few weeks ago it rained often enough that I didn't need to water. I checked the trees at least twice a week and am almost certain that the ground never dried up. The first tree died before the heat wave, and I watered all the trees deeply the day before the heat wave began. Yesterday I dug up one of the dead trees and didn't find any evidence of insect or disease damage, and the roots had expanded a lot since planting.

 

[Rtom45]

Maybe the hardwire cloth is causing the trees to "burn up". Hemlocks like shade, could be the high temperatures and wire cloth are dessicating the trees even though the soil is moist.

 

[Adkpk]

Sounds like drout to me. It take trees time to die from drout. I have a limb of a yew I cut weeks ago with a fresh green spig on it. One day it will suddenly be brown and dead. Seen it happen before. I think they got dry in the shipping and are taking there time to look dead.

 

[Kneejerk Bombas]

Are there commonalities to the dead trees?
Are they near a Black Walnut or did the chips come from a Black Walnut?
Anyone ever grow ginsing on the site?
Pull out the dead trees and check the roots for clues.

 

[wysiwyg]

The trees have been in the ground since April (planted dormant) and were actively and prolifically growing until they suddenly dropped dead a few weeks ago. The dead trees are no where near black walnut. I pulled one out a while ago and found nothing noticable about the roots, except that they had grown extensively since they were planted. The trees are not mulched - they are in a low area that holds moisture well, also they are in 75% shade. My only theory right now is that a dog or some other animal pee'd on them or close enough to them that it soaked into the root area.

 

[Adkpk]

Most evergreens like well drained soil.

 

[wysiwyg]

The soil drains just fine, but there is so much organic matter in it that it takes much longer to become bone dry than the other soils on our property. All the conifers and oaks grown in these areas just love it (once they are established)