Three Things You Need To Know About Armillaria Root Disease

Armillaria root disease, also called as shoestring root rot or mushroom root rot, is a fungal disease that may affect your pine trees. Here are three things you need to know about Armillaria root disease.

What are the signs of Armillaria root disease?

If your pine trees are afflicted by Armillaria root disease, you may notice that their needles are becoming brown or stunted or that the needles are being shed. You'll notice that new needles are not growing back to replace the ones that have been lost. Peeling bark is another warning sign of Armillaria root disease.

Stunted trees are another sign of this disease. If one of your pine trees is much smaller and thinner than the others, it may be diseased.

In severe cases, fungus can actually be seen growing out of the soil around the tree. Look for white or black growths that look like shoelaces popping out of the soil. You may also see white or tan mushrooms around the base of the tree, which are an indication that the roots are rotting.

How do trees get Armillaria root disease?

The shoelace-like fungal growths that spread from your tree's roots are the way this disease spreads. When these growths reach a nearby tree's roots, that tree is infected as well.

These can also be spread if an infected tree is cut down and not disposed of properly. If you cut down the tree but leave the stump in place, the infected roots— and the fungus that is living on them—will still be in place and will continue to spread.

How can you control Armillaria root disease?

Armillaria root rot can kill trees very quickly, so you need to act fast to save your tree. Remove about three to four inches of soil from around the base of the tree, and then apply a systemic fungicide spray onto the trunk of the tree. This spray should be repeated every one or two months. Make sure to re-cover the exposed roots before the freezing temperatures of winter arrive.

If your tree is already dead, it will need to be removed. It's important to remove not only the trunk of the tree but the roots as well. A tree service can use a winch to pull the stump of your tree out of the ground, and then a mini-excavator can be used to get rid of as much of the remaining root system as possible.

If you think your trees have Armillaria root disease, contact a tree service right away to try to save them. Check out sites like for more information.