Hello Our small city sized (Portland Oregon) backyard is southwest facing but under a shade canopy from 35 foot plus trees: an English Walnut and a similar height Mimosa / Silk Tree (Albizia Julibrissin). I removed a dozen smaller trees and bushes in this overgrown yard when we bought the house, and I thought that this improvement of the amount of light plus amending and aerating the soil and would allow for a small grass lawn for our very young children to enjoy. I chose grass just because that was all I really have experience with as a resilient plant for running and wrestling and laying. Then I read about juglone. Uggh. I am now rather concerned the bareness of the backyard isn't a result of the lack of light or of poor soil but of the walnut's toxicity. And I could be spending a bunch of time and money to plant something that is just going to die. Does anyone have any success with growing a lawn partially under or just outside of the canopy? Or better yet, a moss or other soft yet hardy groundcover that could: · Tolerate shade · Withstand kids playing etc. · Resist the juglone Thanks in advance stephen
We have a large English Walnut tree in our backyard in Boise, ID and grass grows under it very nicely.
Persian Walnut (more accurate name!) produces much less juglone than Black Walnut. Not enough to cause a problem for any other than the most juglone-sensitive plant species.
You can grow a grass under the canopy of an English Walnut but three requirements are needed in order for the grass lawn not to die out later on. One: is to allow plenty of light to pass through the canopy of the tree into the lawn. Two: is try to keep the soil well aerated as best as you can and you may need to apply some soil amendments and lots of applied water (or rely on ample rainfall) every few years in some locations to help you along in this regard. Three: the cultural cleanup of the fallen snouts (catkins), any fallen leaves that may get wet from rains and wet to moist, blackened husks are imperative to better keep the grass lawn in good growing order. The juglone from the roots is not your biggest issue, it is the juglone from other parts of the tree allowed to stay on the ground is what can kill even a well established lawn later on. I have many of my Violas growing under the canopies of three 40+ year old Walnut trees, one is a black Walnut, and they do well there and also have some Spring bulbs growing about 10 feet from the base of the trees. Ryegrass and Fescue seem to do the best for me here, whereas Bermuda grass and some of the Bluegrass can perish rather soon if any fallen wet leaves are allowed to stay on the ground and stick like glue to barren ground there for any length of time. I try to have all of the leaves raked up and collected before they ever get wet but some years I have not been so successful and have lost some of the lawn, over the years, accordingly. An uncle of mine has had two Hartley Walnuts in his front yard for many years in a Ladino clover lawn with no barren spots in front lawn at all with his relying on cultural cleanup of the fallen Walnut debris. Jim
Thanks to both of you even though I didn't request this knowledge, but it is very helpful to know and due to my own experience of having walnut leaves, walnut husks and catkins left on the ground, not that I wanted to, I've experienced the same problems as far as growing grass underneath the tree. My tree is in the back of our acre property on a slope and gets a bit neglected as my sons grow up and leave. Also, the eldest son still has a ford truck bed right next to the tree which is very annoying and he has his own acre property to start moving all of his truck parts and pieces, which is a big job. So since he can't see it and it isn't interfering in his life then it continues to stay. Unfortunately, I bought out a nursery so all of the tables, display racks and pots galore are sort of in his way as we had to put those somewhere quickly. I have a hoop house to get set up and that involves more of his truck parts removed, so it seems to be a Catch 22. I just keep working around it planting where I can and when push comes to shove my son will have to get it moved, no excuses. Right now the walnut tree is a delight and all the branches are leaning down making an umbrella effect of shade and privacy. I want to have a picnic under it with my two little grandchildren. And some relaxation time in lounge chairs with the rest of my family, maybe with a small portable firepit. We have a man made creek running down the slope to the other side of the fence down to the main creek, so it is such a restful fairytale atmosphere that should be enjoyed in the future. If it could happen this fall, I would be very happy!
Thank you all for your contributions. Since reading this I have followed your advice and attempted to chase down the droppings within days of their falling (and there sure is a lot to chase (walnuts, leaves twigs). The lawn does well until about mid-summer August and then thins out. I kind of just assume that I will have to restore it a bit - kind of an annual spring ritual: so I plant a few pounds of shade-tolerent fescues to fill in every year and with the large amount of rain we get here the grass takes off. So we get along. Thanks again!
I have two large well established walnut trees on my property. One is a black walnut, 70 ft, the other an "English" walnut, 30 ft. Both are infested with Black Widow spiders & more evidently so than any other trees or plants in my garden. The only other places I consistently find resident black widows are in the large rocks behind retaining walls & undisturbed stacks of wood. My daughter, 30 miles away, has 10 walnuts, 25-40 ft, with the same black widow infestation. For this reason we tell the grandkids to steer clear of the walnut trees.
Volunteer English ivy & sweet alyssum are thick under my English walnut. I weed out the occasional wild oat or nettle. Under my block walnut, which has a much higher canopy, I find a smattering of wild oat sprouts, clumps of wandering jew& a rare forget-me-not. I clear everything out from under the black walnut late spring & fall. I never irrigate but receive a good sized crop of nuts. I have a dry California coastal summer with morning fog.
The fescue seems to grow up to my jungland nigra bkack walnut thicket just fine. There are a dozen or so in the grove. Fraxinus americana white ash, cherry trees, the hated honeysuckle, some elderberry, the hated grape vine and volunteer redbuds grow in ths grove. Oh, and one of three viburnums I planted. FWIW, even though I own the north side of the grove the walnut grove they get their leaves soo late and lose it soo early I don't think their shade is too overpowering