A poster's location is always one of the first things needed (most veterans here put it in their names). SEEMS like you sideways mention TN as location, so if correct, neither red or white spruce will grow well there -- summers too hot and humid. Lists I see mention some conifers as not tolerant (like Norway spruce), but I see no list that says any conifer is tolerant.

PS -- Norway spruces might reseed alittle here and there (I might have seen one in my whole life of tree observation), but sources that say Norway spruces are invasive in east US/Canada are scare-mongering. Colorado spruces are always going to be problematic in east US summers from various ailments, tho they do better toward the Canadian border.

That would be an overstatement. Virginian juniper is a conifer and usually listed as tolerant.

As for blue spruce, indeed, they suffer from ailments in the eastern USA's humidity. They're more used to arid places like Wyoming or New Mexico with few pests to speak of. We had to step in and save mine until it got bigger, and I actually lost two along the way.

I fiercely disagree about white spruce, though, simply due to personal experience. Black Hills spruce (a subspecies of white spruce) is often said to be the most heat-tolerant North American spruce, and I've seen healthy dwarf Alberta spruces throughout Tennessee - even in Memphis. I've also seen a white spruce that clearly wasn't dwarf Alberta healthy in-person in Algood, TN and in street view in Louisville, KY. In fact, my Black Hills spruce saplings were shipped from Rhea County, TN, which is further south in the state than here and doesn't have any especially high mountains. For over a decade, two dwarf Alberta spruces mom planted have survived in an especially hostile microclimate (dark red flowerbed along a dark red west-facing wall in a sunlit, wind-sheltered yard), but they've only grown enough to heal the damage rather than truly flourish; the two she planted for my grandmother are exposed to our usual climate and have truly flourished.

As for red spruce, I was definitely skeptical too, but I've heard that they grow just fine in Central Indiana. Maybe they'd struggle in the warmer parts of Tennessee, but probably not the Upper Cumberland. If something grows in Indianapolis or Champaign, it'll probably grow here too. I also recently learned that red spruce was actually found substantially lower in the Smokies than it currently is until loggers ravaged the slopes. Red spruce really just has a high water requirement, and the heavy rainfall in most of Tennessee is enough to offset the evaporative losses that come with a warm climate (unless it's something like bigleaf hydrangea that's used to summer monsoons and winter droughts, of course).

In any case, though, regardless of whether white, red, Martinez or any other native North American spruce species can grow here specifically, it could still be handy for others to know which ones are and aren't juglone-tolerant too.

Black Hills spruce is a mutation of white spruce -- mutants can do strange things. If that's what you want, go for it, tho I observe they usually end up poor specimens w/large areas of spider-mite ridden branches.

Indeed, I've called it a "subspecies." It's not quite the same as generic white spruce, but it's still closer to it than a different spruce species outright would be. That doesn't answer the question, though. Are they juglone-tolerant or not?

In a 'nutshell'. ;-)

What evergreen conifers will grow near black walnut?

Tolerant Evergreens

• Chinese juniper. Juniperus chinensis.
• Common juniper. Juniperus communis.
• Eastern red cedar. Juniperus virginiana.
• Arborvitae. Thuja sp.
• Eastern Hemlock. Tsuga canadensis.

Then there's the rest.

Many universities have done studies on this issue and posted results on line.

Here's one:

https://extension.psu.edu/juglone-producing-plants

I have to wonder about this seeming preoccupation with juglone. Most trees will exhibit some degree of allelopathy but walnuts have received an especially bad rap. In the wide screen of things, very few plants have been proven to demonstrate a strong reaction to juglone. A good many other plants have difficulty growing under or adjacent to walnuts not due to juglone but for the simple reason the conditions are shade and dry soils - dry shade is a difficult situation for many plants.

So while the published lists of known/documented juglone sensitive plants is fairly limited, the lists of those plants that appear to have little or no reaction at all is almost endless. Unless you are planting directly under the tree canopy (problematic for various reasons), chances are excellent that most plants - excepting those like tomatoes or rhododendrons that are known to be reactive - should be fine.

If the plant in question is not evident on a list of juglone sensitive plants, go for it, Juglone is just not that big a deal.