Tree Roots in Lawn

Raised Tree roots in a yard.

This is one of the most often asked questions I get in this heavy clay soil area.

What causes raised tree roots?
Trees need air space called macro pores in the soil or they suffocate. Heavy soils such as clay have less macro pores. Macro pores are created when organic material breaks down actually leaving an air space. So if the tree is growing in a soil without enough oxygen, it will push up the roots looking for that air space.

Water will fill this air space. So if you water too much, the tree will again, push it's roots upwards seeking a better environment that it can survive in.

How do we fix raised tree roots?
Well we do not cut the root unless there is no other alternative. There are five main scaffolding roots the tree is using to support itself and to gather nutrients. If you cut one of these it would be like your diet being cut by 20% and your leg being cut off below the knee.

There are two good ways to properly take care of raised roots.

1. Amend the soil with organic material. The best way to do this is with the air spade we talked about in the earlier blog. This breaks up the soil and allows you to amend it with more organic material. This should be done by a professional ISA Arborist who has been trained in this specific work. A tree well, as wide as the drip line, is ideal although not often practical. This area can be covered in mulch. The best mulch is ground leaves which is what the tree would indigenously use.

2. The second option is to put a mixture of organic material like a leaf mulch or well composted material, in with a sand mixture, and cover the roots with an inch at a time. The grass will grow through this material well and actually thrive in it. Every few months add an extra inch until the root is completely covered.

Be sure to adjust your watering habits. Check the tree moisture within the drip line. This is best done with a water meter. The cheaper meters will work fairly well and be better than nothing at all. The tree should be wet once a week, and to the middle of dry on the meter, once a week, at least 6 to 8 inches down. If it is pegged wet all week, you need to adjust your watering.

Do not run over these roots with the lawn mower and scalp them. This allows disease and bacteria into the root system which can eventually kill a tree. If you've done this, leave it exposed and allow the tree to heal itself by compartmentalizing the wound. That is that rolled up look you see on old wounds. Once it has done that, use one of the above methods to cover the root so it doesn't happen again.

Root care is the foundation of the tree's health. Good link for Tree Root basics.

Trees Biggest Enemy

Keep in mind that the "arteries" of your tree is just below the outer bark called the phloem and xylem. If this is damaged it is like your artery system being damaged.

So the biggest enemy your tree faces is devices that can damage those arteries.

Who is the biggest Enemy?

Unfortunately it is us.

Lawn Mowers and Weed Eaters do more damage to trees than any other one item in the Tree World.

It's not really our fault in that we are trying to do a good job, getting the grass mowed down, that is growing up around the tree. But in reality that grass would not be there in nature, the tree leaves and needles would blanket the area and choke out any other grass or weed. We remove that natural mulch.

The other problem is we don't want grass to build up a thatch layer around the trunk flare and suffocate that cell tissue.

AND, we don't want the grass to compete with the tree roots directly around the tree. So lots of reasons to get rid of that grass right around the tree with a tree well.

How do we make it? Very simple, if it's a mature tree simply spray the active ingredient found in round-up called Glyphosate - generic version will work fine and cost a lot less. This product used properly will not harm mature trees, see link.

Simply spray around the tree like this. Notice the card board cut out to make it nice and even. Be careful that you don't drip on the lawn when you remove the card board.

If it's a young tree with soft bark, cover the bark also to keep the chemical off the tree and use far less product so it can not move into the younger tree roots. I've done this for years and never had any damage.

Do Not cut this grass out with a shovel in that there are roots just below the ground you may damage. Let the grass die down, then carefully weed eater it right down to the ground, and you have a safety zone from trees biggest threat.

Trees Planted too Deep

The area going from the trunk to the roots is the trunk flare which makes up a very critical cell structure for the tree's transition from full oxygen to earth.

Covering this area will lead to decline and will show damage in the tree around the 12 to 15 year age span.

Damage will be acceptability to freeze kill back on certain branches, reduced leaf size and overall canopy fullness. It's like a slow starvation for the tree.

Here is a very detailed article about the symptoms.

A tree should not look like a fence post or telephone pole in the ground. There should always be some kind of flare out from the root structure. If there isn't you need to uncover that area. However what you will often find is that the tree is pushing adventitious (small fibrous looking roots) up around the trunk flare now.

It is not a good idea to use a shovel in this are in that you can damage the larger scaffolding roots or trunk area. The answer is to use air. The industry name is a airspade which simply means a large volume air compressor blowing the dirt off the root system.

You can see how the dirt flies with concentrated air power. This work above is loosening compacted dirt around the roots, you can see the trunk flare is fine on that tree. Below is a tree that has been air excavated after being planted too deep and showing signs of decline.

You can obviously see the dirt line, we are just getting down to the root flare at the bottom

For More on this case click here.

 

You can rent an air compressor and begin excavating that area around your tree if this is an issue. Warning; you will take a dirt bath so wear all the safety equipment to protect yourself.

 

Drainage off this root area is also important and can be done at the same time.

 

Spring Tree Fertilizer

Every year I am called out on trees that are struggling health wise and hear the customer say, "well I put spikes in all around the tree to fertilize it and help it."

Fertilizer can be the worse thing for Tree Health Care if you are using high nitrogen.

As a Certified Arborist I am held to ISA ANSI standards which is comprised of top Tree Care Professionals around the world with the latest University studies and research. ANSI has reduced the nitrogen recommendation by 60% a year. I try to help customers understand the reason for this by pointing out that an Oak tree grows slowly and  is strong,  Poplar tree grows fast and is weak. The faster the cell elongation which is a key to nitrogen the weaker the tree.

Nitrogen is NOT what makes a tree healthy. Correct soil around the drip line of the tree is what makes a tree healthy and the trees ability to absorb the minerals around that tree. This brings us to Mycorrhiza the living organisms in the soil that penetrates the roots of trees and transfers minerals for the sugars the photosynthesis process in the leaves have created. This is what makes a tree healthy and self sustaining.

Products such as Organic Tea and additives such as SAVE-A-TREE as pictured above creates this environment. Spikes, too much lawn fertilizer and nitrogen applications are not your first step this spring. Large tree wells with well aged composted material such as the indigenous leaves are best with the focus on building better soil directly around the tree.