Of walnut trees, zones and vegetable patches

I live in a borderline Zone 4/5 area. Our winter temps have reached or gotten colder than -20F only twice in the last 20 years. However, that's just often enough to remind us of where we live.

I've been laboring under a few delusions about walnut trees, such as that only the Black Walnuts are hardy enough for our zone, that their fruits are bitter and that they need constant TLC to reach maturity. But a few weeks ago I happened across an English Walnut growing in one of our parks, and it was obviously mature. Also, someone told me that Black walnuts have a richer flavor and their wood is more valuable. I've consulted a number of knowledgable sources online and off, including the almighty Dirr, and there are still contradictions, so I'm hoping some of you in a similar zone may have had real experience to relate.

Is it just that the English Walnuts need Zone 5 temps to get established, and then afterwards they can take occasional Zone 4 weather?

Which do you prefer between the Black and the English? For shade/ornamental value/wood/fruit?

Is it true that walnut trees impair the health of a vegetable garden if they're close to each other? How far away from a walnut grove should one keep the veggies? Does it help to have the veggies upwind?

Once you amend heavy clay alkaline soil to a better composition for walnuts, how often after planting should the soil be refreshed to keep the trees healthy?

Do walnuts grow well from cuttings?

Any info at all would be so much appreciated!

Walnut trees do produce chemicals that inhibit the growth of many other types of plants, there are some plants that do fine under walnuts but for best results I would plant the veggies outside the root zone of the walnut (most veggies want full sun anyway, so you wouldn't want them too close to any sort of tree). Being upwind won't help, the chemicals are in the soil.

As far as amending the soil, I personally wouldn't recommend amending the soil for trees--unless you can amend a really large area you are better off not doing it...the tree's roots are going to have to grow out into your clay soil at some point, and they will have an easier time doing it if they don't have a pocket of nice amended soil which they will want to stay in. People who amend the planting hole for a tree, especially if they have clay soil, often end up with the tree becoming rootbound inside the planting hole because the roots want to stay in the nice rich amended area and don't want to go out into the clay.

It may also depend on the size of your property. Black walnuts are usually larger than English ones. I personally large stately trees myself.

Any walnuts, and especially black walnuts, will not just inhibit but kill a lot of plants, including tomatoes, roses - there's a long list. And that's anywhere within 80 feet of the tree. And it will persist in the soil for many years even after a walnut tree is removed. Unless you have a really large yard, I'd suggest you pass on the walnut trees.

For more information, do a Google search for juglone.

I wouldn't worry about growing a tree for the value of its wood either unless you're a woodworker who wants the novelty of making something from a tree you grew. By the time you pay someone to take down the tree and a mill to cut it into lumber and then properly cure it, either yourself or paying someone else, you could have bought the lumber.

Black walnut, butternut, some of the butternut-Japanese walnut/hearnut hybrids, and probably a number of the pure Japanese &/or Manchurian walnuts(nuts very similar to butternut) should be hardy for you in a zone 4/5 setting.
I've dabbled very little with the Persian/Carpathian types, as I've just been singularly unimpressed with all I've ever had the opportunity to sample. I just don't care much for them, and most had more astringency than a good black walnut, and certainly less flavor.

The heartnuts and butternut hybrids tend to make a very nice spreading shade tree, with a more 'tropical' appearance than black walnut.
Personally, I think the juglone problem is overstated, though I have no doubt that for some plants, it's a real problem; but, in many cases, I'm inclined to think the 'suppression' or 'toxicity' is more a feature of the larger tree shading or out-competing the smaller plants for available water/nutrients.
As stated earlier, all the walnuts produce juglone, but black walnut is the 'heaviest' producer.

I prefer Black Walnuts even though they are heavy producers of juglone. Don't be afraid of planting that species. There are many zone 5 plants that have adapted to not only surviving but thriving quite well within the dripline.

ditto with don't worry too much about the juglone- Here in NH we are swamped with butternuts, the squirrels plant them everywhere, and black walnuts grow well too- growing up under these kinds of nut trees had one problem: It really hurts when one falls on your head. I have never noticed any lack of vegetation under any of these trees, and personally had a flower bed that a black walnut leaned over, roses, and all.... My favorite for taste is black walnut. A heck of a nut to crack, however. and remember too, that they get quite large.... Have you thought about filberts? more of a large shrub, really..

We inherited a very large old Black Walnut when we moved into this property. For two years, my Other Half was completely frustrated in attempts to grow a vegetable garden near the tree, despite proper sun, soil amendments, feeding, etc. This year we learned about juglone, and it now makes sense. Not only were the tomatoes a lost cause, but also the cucumbers, berries, etc. Flowers and bulbs seem to do fine in its root zone, but shrubs and veggies have a real problem in our experience.

We have a large Black walnut tree...I have a dogwood, lilac, and 2 cedars around it. They are doing fine, my garden was about 5 foot from the walnut tree...but I do container gardening, because it is just the 2 of us, and the ground is like red concrete here.