I'm following this thread because I think I know what's going on and I want to find out if I'm right. Others here will have better answers, but I'll try. I'm going on the assumption that yes, those are plums making the thicket. Plums do that. Also, plums send up lots of suckers, which means that there is at least some connection underground. There may be some seedlings growing too. My thought is that they are tough and resilient, and that you should go in and remove 90% of them by any means possible- saw, shovel, backhoe, whatever it takes. Thin mercilessly to one plant every several feet. Pick the best-formed plants to stay. Get rid of anything else. Remove roots as well as trunks- and pretend that each plant that you leave would do well in a big pot. Continue to remove competition all summer and all next year. Then, treat each remaining tree as you would had you bought it. (I'd train to central leaders, even though these're plums, but others may wisely recommend bases.) Now I'm open to corrections. Please!! :-) Thanks all, M

John H. Gordon grew - and offered seedlings - of the 'Covel' manchurian walnut - or a hybrid of it - from his nursery in Amherst NY, where he specialized in nut trees for northern growers. (JHG passed away several years ago...don't think the nursery is still in operation, but parts of his website are still up - linked below) 2007 was a disaster - and a good illustration of how important it is WHEN it gets cold, as compared to HOW cold it gets. Butternut is noted for its cold-hardiness...but we'd had an exceptionally warm Feb/March - with several days in March with temps into the mid-80s. Things had broken dormancy far too early - I had pecans/walnuts/persimmons with 8-10 inches of tender new growth...then, 4 consecutive nights of temps into the teens, at Easter. Killed a lot of things outright, some just back to the root collar. Big mature oaks/hickories in the forest here were killed back to their main trunks - branches larger around than my thigh...dead. Some of those trees are still dying off after that insult and the ensuing drought that followed; it's just taken a while... Here is a link that might be useful: John H. 'Nuttree' Gordon

Hey Ann, long time no "see". :) I don't know if silver eleagnus (winter blooming eleagnus) is hardy in your zone but it makes a wonderful hedge. I've got it as a secondary hedge behind the leyland cypress so when that goes, there's still some privacy left. The first plants of it that I planted (gulp) 7 years ago are 10' tall now and they were only 1 gallon specimens then. I've rooted countless others since then as it's really easy to do. Stick a trimming in the ground in fall and it's taking off the next spring. A big bonus is that it blooms in late fall and smells divine. My black bamboo is supposed to be a runner, but in 5 years, it's barely grown 4' in width. It has matured enough to reach 15' high and the canes turn black though. It's lovely! A mixture of it and some white striped passalong clumping bamboo is the basis for a future "Japanese are" if I live that long. LOL! Another neighbor has some shorter holly planted boy/girl boy/girl in a close enough configuration that it all looks like it has red berries in winter. Only problem with it has been the invasion of the honeysuckle. Crawling around under a holly trying to get to the root of they honeysuckle is BAD job! Even on a "single point" holly! LOL! The absolute cheapest hedge you can grow is probably cedar. The ones I planted 16 years ago on this property are now 20' tall and totally screen the neighbors on one side. They were just tiny "bird droppings" plants that I harvested from the woods at the back when I planted them. Those are probably lining your property everywhere waiting on you to either mow them down or brushkiller them. The quick hedge would be the silver eleagnus in larger containers and plant the tiny cedars 15' away and then you'll have a 2 layer hedge with enough room to get in and weed out the blackberries and oak seedlings. Or, there's always poke salad. It's hopeless to weed out anyway, so go with the flow and use it's invasive evil properties! :)

Not sure about dog proof, but here's some things that are suppose to grow under and around black walnut. astilbe, bee balm, begonia, bellflower, bergamot, bloodroot, Kentucky bluegrass, spanish bluebell, virginia bluebell, bugleweed, some chrysanthemum, coral bells, cranesbill, crocus, shasta daisy, daylily, dutchman's breeches, ferns, wild ginger, glory-of-the-snow, grape-hyacinth, herb robert, hollyhock, hosta, hyacinth, siberiean iris, jack-in-the-pulpit, jacob's ladder, jerusalem artichoke, lamb's ear, leopard's bane, lungwort, mayapple, merrybells, morning glory, narcissus (some) pansy, peony (some), phlox, polyanthus primrose, snowdrop, solomon's seal, spiderwort, spring beauty, siberian squill, stonecrop, sundrop, sweet cicely, sweet woodruff, trillium, tulip, violet, virginia waterleaf, winter aconite, zinnia.