tomato plants and walnut trees?

[ArcticCat]

I have had two very healthy plants just wither up and die in the past week. Both we planted in full sun, but just under the south end of a walnut tree...

My wife said she recalls hearing the two dont mix... this true or have I another problem?

I have since transplanted one, but its not doing well.



Ken

[tam91]

Yes, walnut tree roots (and I think even leaves etc. also) release juglone a substance that poisons many plants including tomatoes. You need to keep tomatoes outside the drip line of a walnut tree, and probably even further away. I've read the roots can extend 50 feet or more. I learned this the hard way.

I'd suggest moving the other one, then watering the heck out of the plants, to wash out any juglone remaining. No guarantees unfortunately.

[delltraveller]

You don't say if you're dealing with English walnut trees or Black walnut trees, but around here, with the Black walnut trees, the general rule of thumb is to be 150' from the trunk of a Black walnut tree for things like tomatoes.

The buds, nut hulls and roots of the black walnut tree have the highest concentrations of juglone, aka 5hydroxy-1, 4-napthoquinone, but it is also present in stems and leaves. Plants vulnerable to juglone need, at the very least, to be outside the canopy of the tree.

English walnuts, butternuts, hickory and pecan trees have juglone, but usually in quantities so small as to usually have little effect on other plants.

Tomatoes, peppers, eggplants, potatoes, cabbages, rhubarb and asparagus are vulnerable plants.

Onions, lima and bush beans, squash, melons, corn, carrots, beets and parsnips are tolerant plants.

From direct experience at my grandmother's house, black raspberries and bluebells, violets and daylilies are tolerant.

If you have an English walnut tree, I'm betting it's something other than juglone toxicity.

[ArcticCat]

tomorrow I will go talk to it and try to see if it has an accent... then I'll know if its English...

The one I left died, the one I transplanted nearly died, but seems to be making a rebound. but has plenty of damage. Yellowed leaves and vines.

[Worth1]

Originally Posted by ArcticCat

tomorrow I will go talk to it and try to see if it has an accent... then I'll know if its English...

The one I left died, the one I transplanted nearly died, but seems to be making a rebound. but has plenty of damage. Yellowed leaves and vines.

Unless you can speak Arabic you wont understand your walnut tree if it is an English Walnut.
You see it was developed in Persia over 2 thousand years ago and was thought to grow in the hanging gardens of Babylon.

Worth