To Stump Kill or Not to Stump Kill...Next to a Live Tree

[Katie B.]

We had a row of white poplars cut down yesterday. Seven were completely dead, but three were living (2 stressed but 1 that is robust). We decided to hold on to the one tree that is very healthy for shade purposes. We are now trying to decide if it is a good idea to make a fresh cut on the stumps of the previously living trees to put down stump killer. One arborist told us that the roots of these trees fuse together, so placing stump killer might kill the living tree. Another arborist told us there is no need to place stump killer on the trunks of the dead trees. Any thoughts on this?

We will be grinding the stumps eventually.

 

[JTM]

Leave it alone

 

[Jakers]

i would not use any kind of chemical on it. the roots will most likely be grafted together so killing the stump will also kill the tree next to it. grind the stump and let it go at that

 

[Katie B.]

Thanks for the responses. We'll skip the herbicide.

 

[BC WetCoast]

Was it true white poplar? Populus alba If so, these are very colonial trees, in that they grow in clumps/colonies, so I would expect new stems growing from the roots this year.

They are definitely on my hated tree list.

 

[Katie B.]

We thought they were true white poplars. However, an arborist suggested that since they died earlier than expected (18 years) they might have been crossbreeds. We did buy from a reputable nursery, but he said crossbreeding is not uncommon. In our area there are white poplars that are 150 years old so we were hoping for a better outcome. We are still sad about it. In fact, my avatar picture is a snapshot of the trees in early spring. Working on letting go...

Another arborist suggested it might have been the weather. We have had several extremely late freezes in the last couple years that have killed many poplars. One farm lost 40 trees in one year. No borers in our trees and nothing else we could see that would have killed the trees.

The backside of our house gets really hot in the summer, even with AC, so we left the last tree in for shade. It's a gorgeous tree, but I'm not looking forward to dealing with suckers. Many years ago a neighbor dumped some leftover Round-Up in the back corner of his house, right next to one of our trees, not realizing this was a bad idea. This tree became very stressed (in fact, it never grew in height after that) and sent out tons of suckers. We would clip them, and it was such a big chore. Any suggestions for dealing with the suckers?

 

[Jakers]

Pay to have the stumps ground then fill in with dirt. Any suckers that grow from roots will be easily mowed off. If you're asking about suckers on the sides of the remaining trunk, cut them off of you don't want them. Usually if a tree is shooting tons ofsuckers off the sides it's a good sign of stress or a dying tree. The bur oaks we have around here and boxelder will shoot suckers out the sides every year even if not stressed.

 

[Katie B.]

How deep should the stumps be ground? We did end up having them ground, but we were surprised that the grinding only went down 6 inches and that some of the perimeter of the stumps weren't ground at all. (Unfortunately on the day the stumps were ground he arrived a littler later than we had hoped, and I had to leave for an appointment before he had finished. I wasn't able to inspect until after he had left).

Previously, we had many people give us bids, and one individual told us the stumps would be ground so deep we could plant a tree in the hole. Unfortunately we assumed that what he said was standard practice. At only six inches down, we are hitting wood. There is no way we could plant another tree in the same spot. We do need to replace the trees we took out, and we're concerned that the spaces in between the trees (about 10 feet between each tree) will be full of thick roots.

Of note, one of these trees fell down in a storm last fall, and the root ball was surprisingly small (considering these trees ranged in height from 45-65 ft). I suppose it had rotted and shrunk. I believe it would have sat about 12 inches deep into the ground. But, this was by far our thinnest tree. The other root balls may be much larger. The gentleman who ground our stumps has a little more work to do, so we were planning to discuss this with him. What would you say is a reasonable depth for stumps to be ground?

 

[Jakers]

4-6 inches is pretty standard depth for smaller machines. Some of the biggest machines can go to a max depth of around 18 inches deep. Most people just plant grass in place of the trees which only needs an inch or two of dirt to grow. At any rate, your stumps should have been ground to below the surrounding grade. This includes any exposed roots and any root flare containing wood.

I usually tell people to plant their new trees a minimum of four feet away from the old tree stump. The new tree will take a few years to establish good roots so in that same time the stump will soften and rot some. If it's imperative that the new tree go in the exact same spot then my recommendation is to dig out the entire stump to immediately accommodate the new tree. If you have 10ft between stumps I'd plant at the five foot mark.

Remember that anything you put under or near your one remaining tree will be in the danger zone when the time comes to remove that last one

 

[Katie B.]

You've been very helpful. Thank you!

 

[Jakers]

I own a tree service myself. Questions and information are my specialty. You're welcom