Why Did My Tree Die?

Kalie Larkin Expert Advice, Plant Care, Pruning Leave a Comment

My Tree Just Died

There are times we look at the trees in our yard and it seems like they were doing great just yesterday and today they are dead. “Why did my tree die?” is a common question we hear all the time. The two killers I want to mention are subtle because they attack the trees supply system instead of its above ground structures. Some of the affected trees will look perfectly normal when they leaf out in the spring but once the heat of summer hits they die back. We see this because the tree use up all the nutrients they had stored in their upper portions in the spring but then they had nothing left to draw on once the summer hit. These common killers are root crown rot and girdling roots.

Root Crown Rot

This is more of a universal label for any biotic or abiotic factor that leads to the destruction of a plant’s lower trunk or root system. These causal agents can kill a plant within a season but are more likely to affect a slow decline that is unnoticed until the plant finally gives up. The consistent theme for all root rot is the presence of constant moisture around the roots/ lower trunk. Any tree or shrub can experience root crown rot but we have noticed that our area shows it is most common in honeylocust, poplars and fruit trees. Many plants will start to show symptoms consistent with drought which causes a conscientious homeowner to increase their watering regimen, aka making it worse. Excess moisture will be readily evident by a discoloration of the trunk just below the organic material line, fruiting bodies or even standing water.

Girdling Roots

Another subtle killer of the plant world is girdling roots. A girdling root is one that has turned on itself to start wrapping around the tree/ plant instead of heading out towards the edge of the canopy. As these roots get bigger and bigger they will start to cut into the plants nutrient/ water pathways. These roots can take decades to finish off a tree but most often take 3-7 years after planting to do their dastardly deed. Plants that were root bound in pots prior to planting or that were planted too deeply are at the highest risk for developing girdling roots. Even in those categories some of the most commonly affected trees around here are the lindens, pines and maples. You can be suspicious of girdling roots if your tree is showing a well-developed flare on one side while it is absent on another side. Though it is hard to tell in young trees as their flares are not yet well developed.

Both root crown rot and girdling roots are on my top ten list for sneakiest killers, but there are a couple of ways to diagnose these problems. The first is to check the internodel growth of the tree/ plant. That means to measure how much your plant has grown from year to year by looking at the distance from start of one bud scale scar to the next. Trees affected by either root crown rot or girdling roots will show that although the tree has looked fine for the last couple of years it has been in a state of steady decline. The second thing to do is to start digging around the base of the tree. Nothing beats getting down and digging away the top 3-8 inches of topsoil.

If you’re not sure what is going on with your trees or would like to have one of our arborists inspect your landscape please feel free to give our office a call at (208) 523- 5296!

Sources:

http://ohioline.osu.edu/hyg-fact/1000/1139.html

http://www.myminnesotawoods.umn.edu/wp-content/uploads/2009/12/sgr-book.pdf

http://www.ext.colostate.edu/pubs/garden/02939.html

http://extension.illinois.edu/treeselector/detail_plant.cfm?PlantID=214

http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn74133.html

http://hort.uwex.edu/articles/root-and-crown-rots/

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