Poisonous and messy, but gorgeous! (http://tree-species.blogspot.com/
So yesterday I wrote about how the Black Walnut poisons other plants and is an all-around nuisance to have in the yard. The Mid-Atlantic Gardener’s Book of lists places this tree on their list of “Trees That Have No Business Being in a Landscape” alongside the likes of Canadian Hemlock and Silver Maple (both of which I have and like — hmph!)
I pretty much go along with the belief that this tree is a major pain in the ass. My largest Black Walnut branches out over our pool, and it drops crap into the water and on the pool deck basically all summer. In the early summer it sheds big yellow catkins, then a little later it’s the giant green nuts, followed shortly thereafter by the leaflets and really looooong leaf stems that get stuck in everything. The decaying nuts leach out a dark-brown liquid that will stain a patio or deck and if you pick one up with bare hands they’ll be stained for days. All of this might be tolerable if the valuable nuts didn’t require industrial equipment to remove the hulls, but alas, home harvesting of black walnuts is waaaay more trouble than it’s worth (at least for me.)
So why not cut them down? Because they are gorgeous! They have a lovely, light-filtering canopy and fantastic, spreading branch structure. So yeah, this tree has many flaws and leaves irritating messes behind all the time, but it is handsome and lovable anyway. Sort of like your spouse.
Black Walnut Dispatch 
saw your comment on Melissa Clark’s blog, Garden Shoots – Love your comment about the tree being a major pain…..good luck with your new endeavor!
Thanks, Susan & thanks for commenting. Pretty cool how this social media thing connects people so quickly!
Have you tried Trachystemom orientalis? I think the common name is Borage or something. I’ve had that growing right up to the crown of Both are so incredibly tough. The Euphorbia is a great option. Would Hakonechloa macra grow under?
I’ve had good luck growing Geranium macrorrhizum under a Sycamore which is also slightly allopathic. Maybe it would work there. Don’t bother with other geraniums, the Bigroot Species is by far the best ground cover. Epimediums? I’ve seen them under some allopathic trees.
I’ve never actually gardened under a walnut, so all of those could be losers. But those are among the toughest dry shade, tree root plants I know.
I have not heard of T. orientalis… I will google it after this reply. The hakonechloa would look great (if it lives!) I will have to try it. The super resilient dry shade plants make good sense — since I think the alleopathy is made worse by water & light deprivation…
I’m made worse, too, by water and light deprivation . . .