Pale dogwood leaves with orange/brown blotches

kmoose · Sun Jul 20, 2014 9:57 pm

Hello everyone!
About 90-95% of the leaves on my dogwood tree have gone a pale yellow/white between the green veins. I've done some research and I initially thought it was iron chlorosis, but now the leaves are showing symptoms that I don't recognize as being associated with lack of iron. Some of the leaves are completely pinkish red, while others are on their way. Many of the leaves are developing brownish blotches (some leaves have holes), and it seems to be getting worse. A couple weeks ago I added iron chelate to the soil around the tree, and today I put bone meal around the base as well as compost.
Does anyone know what's happening to the tree? I would hate to lose it!!
Thanks so much:)

Lindsaylew82 · Mon Jul 21, 2014 9:18 am

Are the leaves over the entire tree doing this?

It looks a bit like borer damage.

Can you see any knots or growths in the bark or stems?

Borers can get in through damage to the bark from weed whacker, or lawn mower damage. Trimming can open up areas for infestation also. The borers disrupt the flow of nutrients and water, which can cause that cholorosed appearance and premature leaf drop/ fall appearance.

https://www.clemson.edu/extension/hgic/p ... c2003.html

kmoose · Mon Jul 21, 2014 8:00 pm

I don't see any leaves that aren't showing any symptoms- some are particularly bad. Borer damage does make sense, but I don't see any damage, knots or growths. But it does have a couple sprouts on the stem, which would indicate a disruption in the flow of nutrients and water.
Do you think it could it be dogwood anthracnose?
Here's a couple more photos. Thanks again for your help! I really appreciate it!

Lindsaylew82 · Mon Jul 21, 2014 9:15 pm

Doesn't look like anthracnose to me, which usually presents as black or brown cankers. There is room for error there, but I don't think it's anthracnose. If it is, it's not presenting in the normal fashion.

It could also just be environmental stress due to heat and drought. Have you been experiencing those?

It IS DEFINITELY chlorosed. Severe chlorosis can cause a lot of issues, including immature leaf drop. The measures you've taken should take care of that in time, but not immediately. If you think the problem is fungal, start treating with fungal foliar sprays, and remove limbs and leaves that look infected. In the fall, remove ALL the fallen leaves. If you have mulch, remove it. Cover the ground with paper and mulch it to the width of the canopy. This will help keep the fungus from spreading next year, it will help conserve water, and it will help with feeding your plant as it decomposes.

Have you tested your soil for Ph? Sometimes the acidity of the soil can make nutrients unavailable for the plants to use. This can cause chlorosis. A simple soil test can tell you a lot of information. My extension does it for free! A quick release nitrogen fert will green it up some. It'll prolly lose those leaves that are already turning red.

rainbowgardener · Mon Jul 21, 2014 11:45 pm

No, I thought about dogwood anthracnose and looked it up. Agree with Lindsay that it does not look like that.

kmoose · Tue Jul 22, 2014 7:33 pm

Thanks Lindsay and rainbowgardener!
Lindsay, we haven't been experiencing extreme heat or drought (here in southern Ontario), but this past winter was particularly brutal! Perhaps the tree did not appreciate the extreme cold, ice storms, or late spring? I'll pick up a simple soil testing kit and hopefully I'll get a better idea of pH and nutrient levels. This might be a silly question, but since I've added iron chelate and bone meal to the soil, would it be too much to also add a quick release nitrogen fertilizer? I don't want to overdo it!

kmoose · Tue Jul 22, 2014 7:59 pm

I'm also looking at other possible nutrient deficiencies such as magnesium. I know that a soil test would finalize all of this guesswork, but the only soil kits I can find are for pH, nitrogen, phosphorus, and potassium

Lindsaylew82 · Tue Jul 22, 2014 10:00 pm

Does Canada have a local extension that you can send off soil to have it tested? My county does in South Carolina. Clemson university in SC will do soil testing, but I'm not sure if they will from out of state or out of country. ( can you send soil out of country?!)

It's very difficult to over feed a tree, especially a larger tree. Blood meal will provide quick-ish nitrogen source. Brewed aerated compost tea, or a tea made with alfalfa meal provide a quick liquid nitrogen source. They sound daunting, but are easy to make. It takes about a day.

Alfalfa meal can't be purchased in pellet form and needs to be soaked for 24 hours. You can also scatter them around and rake it in, but they may heat up, and won't provide that quick N.

Compost can be purchased and then soaked ( I use a 5 gallon bucket with about 3 cups of my compost mixed with water to the top) for 24-ish hours. I usually make it up the evening before I use it, then place it in a spot where it will get sun ALL day. Then I scoop it out and pour in in the root zone.

I've soaked blood meal for a few hours and used it the same way. I have vegetarian family that get wigged out by that, though, so it's not my go to.

I think if you stick to an ORGANIC source of nitrogen, it's difficult to OD, synthetics are not my forte.