Walnut Toxicity

We have a 35 year old Walnut, which is diseased and has to come down. I doubt that we'll be able to dig out the roots. We want to replace the tree with a Purple Robe Acacia. Will the acacia be affected by the toxins remaining in the soil. How close to the original trunk could we replant. How long before the toxins dissipate if we leave the roots in.
Thanks for any info.

 

I'm sorry I don't have an answer to your question but I do have another question related to the topic. What kind of disease does your walnut tree have? I ask because the last couple of years we've had wormy walnut husks and I was just recently told that this is a disease called husk worm and our tree should be sprayed for it. Not having any past experience with walnut trees I would sure appreciate anyone giving me more information about this condition and also, are the walnuts safe to eat?
Thanks.

 

Try doing a search for walnut husk worm on the internet, I'd start with that myself. Kinda doubt the walnut having been there will have much effect on the growth of the locust, unless there did happen to be a soil-inhabiting pathogen or other destructive agent present that did in the walnut and would be likely to then go on to affect the Robinia.

Waiting some months before replanting would give the juglone time to sublimate, if that ends up seeming necessary. I wouldn't be in a rush to plant a Robinia in an important position anyway, these trees can be quite brittle when young. A great many of them planted here that have grown on to make adequate specimens, but have also seen nearly half the crown shear off in one go.

There might be a more sedate and solid tree that provides the same attributes you are seeing in the locust. What are these?

 

Hi Alice

Sorry I didn't get back to you sooner (busy cutting down the walnut tree)
The problem started many years ago, when the tree was allowed to grow unchecked. One of the bottom branches created what an arborist called an "elephant's ear". The branch grew to about a 12 inch diameter, and the weight caused the branch to slowly tear the tree apart. When the it initially happened, bugs, disease, etc, had a chance to get into the tree and by the time I arrived on the scene, it was too late. From the ground up, about six feet of this tree was rotted out. The trunk was perhaps 24 inches across at the base, yet I only had to cut through about 4 inches of wood in the shape of crescent open on one side. The arborist last year gave this tree about 4 years before it would fall over on its own. I didn't want to take the risk for it to fall uncontrolled and took it down myself. We'll miss it.

We chose the Robinia for several reasons: Fast growth rate to replace the shade we lost; beautiful flowers in the spring; attractive light foliage.

I have already dug down, replaced the soil about three feet deep and planted our new tree. We'll see what happens.

 

I think I should do a close inspection of our tree to make sure the same thing doesn't happen here. BTW, how do you treat your walnuts for eating? just dry them?