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View Full Version : Hemlock Yellowing can you help?


Steiner
12-03-2012, 06:50 PM
Central NY landscaper here. I have some yellowing of two hemlocks I installed in late spring. Here are the details:

Details:

Zone 5 Syracuse
Installed in late June
Clay soils
Full to partial sun
Amended soils with 50% compost.
Hole was 2x the size of root ball
Pierced holes in hole to aid in drainage.
Did great all summer and fall. Lush and green. Despite drought.
Customer burlapped trees to protect from drying winds. Not to my specs!

Customer sprayed a desicant product on a few weeks ago before burlapping, then called me last week to come out for yellowing leaves. Hmmmm...

Problem:

Yellowing inside. Green lush inside.

I went over and checked for wooly adelgid but could find no white wool or the reddish pests. I also did the white paper test for spider mites but came back negative. I don't really know what rust looks like but I am hoping someone can clear that up.

As you can see from the pictures I found yellow tips but a nice green inside. Other hemlocks 2 houses down are lush and green. My thoughts are either this product he sprayed, sun scald, or wind damage since the affected area is surface only. He also tends to over do things and I wondered if he watered too much.

Can you help me? Any ideas? I will also post this on arborsite.com.

-Thanks Chris

Smallaxe
12-04-2012, 12:20 PM
In clays soils, I always check the moisture level of the soil, first... then I look at the new growth of the surface roots...
If this is a case of 'chlorosis' then soil moisture is the first logical cause...

Steiner
12-04-2012, 07:41 PM
Ok good point. I am checking with the homeowner to see exactly what he applied.

I wonder if he added the sprayed anti-desicant too early before the tree was dormant? We have had some cold weather then really warm weather here lately.

-Chris

4 seasons lawn&land
12-04-2012, 07:48 PM
looks like some spruce trees I planted in a spot that was way too wet.
So soon after the spraying makes it seem like it was that though

Steiner
12-09-2012, 12:58 PM
Ok customer did say they were yellowing before he sprayed a product called wilt-pruf. I believe him.

My final diagnosis is chlorosis from too much water. He was watering every week with 2-4 5 gallon buckets each.

I would imagine the clay subsoil was not letting the water drain.

So what should I do in that case next time I hit overly hard clay?

1. Raise the ball up and add soil
2. drill drainage holes into the bowl (although it is all clay anyway)
3. Backfill with all clay to remove void space for water to sit.

Could I remedy this by adding a clay cap so to speak above the roots to lessen infiltration of water?

What do you guys do?

Smallaxe
12-10-2012, 10:36 AM
We are fortunate here in that, the areas that have clay only have a 2-3 foot layer, so I dig down to the gravel an backfill with ammendments...
If that isn't possible, I would imagine that a convex base of the hole under the rootball, may indeed work...
Your idea of capping the top of the ground so the water runs away is also a good idea,,, but I always like to be able to dump water into the soil immediately around the trunk...
If you're able to keep the roots wet right at the base of the tree, it won't matter how dry it gets at the drip line... so just estimate how much water it would take to soak up the root ball once a week and use only that amount after your air bubble soaking at planting time...
You might have to monitor plantings for the first couple of weeks personally, just to figure out the correct watering schedule for the h.o. on a case by case basis...

I charge for 2 or 3 visits in the cost of planting just becuz I hate to yell at the client for killing or damaging a plant... :)