We have a tree in our front pasture that has green type nuts on it. If it is a black walnut then I'm probably going to have problems as this small pasture is our biggest pasture (no horses on it yet but soon)..should it be cut down and then let the pasture sit and get rained on? It might be more than one tree .. I will double check.
I have a walnut tree smack in the middle of one of my pastures. Horses pulled all the bark off, and the tree has gradually died. Not one single dead horse though ! The dangerous time is when you get the chainsaw out.
I know a family that has pastured horses in a pasture with several black walnut trees with no ill effects. It would still make me nervous though even though I know the tree itself is not dangerous, just the sawdust from it's wood.
"My biggest fear is that when I die my husband is going to try to sell all my horses and tack for what I told him they cost."
Article more general; Black Walnut Toxicity to Plants, Humans and Horses
Richard C. Funt Jane Martin
The roots of Black Walnut (Juglans nigra L.) and Butternut (Juglans cinerea L.) produce a substance known as juglone (5-hydroxy-alphanapthaquinone). Persian (English or Carpathian) walnut trees are sometimes grafted onto black walnut rootstocks. Many plants such as tomato, potato, blackberry, blueberry, azalea, mountain laurel, rhododendron, red pine and apple may be injured or killed within one to two months of growth within the root zone of these trees. The toxic zone from a mature tree occurs on average in a 50 to 60 foot radius from the trunk, but can be up to 80 feet. The area affected extends outward each year as a tree enlarges. Young trees two to eight feet high can have a root diameter twice the height of the top of the tree, with susceptible plants dead within the root zone and dying at the margins.
Not all plants are sensitive to juglone. Many trees, vines, shrubs, groundcovers, annuals and perennials will grow in close proximity to a walnut tree. Certain cultivars of "resistant" species are reported to do poorly. Black walnut has been recommended for pastures on hillsides in the Ohio Valley and Appalachian mountain regions. Trees hold the soil, prevent erosion and provide shade for cattle. The beneficial effect of black walnut on pastures in encouraging the growth of Kentucky bluegrass (Poa pratensis L.) and other grasses appears to be valid as long as there is sufficient sunlight and water.
Gardeners should carefully consider the planting site for black walnut, butternut, or persian walnut seedlings grafted to black walnut rootstock, if other garden or landscape plants are to be grown within the root zone of mature trees. Persian walnut seedlings or trees grafted onto Persian walnut rootstocks do not appear to have a toxic effect on other plants.
Horses may be affected by black walnut chips or sawdust when they are used for bedding material. Close association with walnut trees while pollen is being shed (typically in May) also produce allergic symptoms in both horses and humans. The juglone toxin occurs in the leaves, bark and wood of walnut, but these contain lower concentrations than in the roots. Juglone is poorly soluble in water and does not move very far in the soil. Walnut leaves can be composted because the toxin breaks down when exposed to air, water and bacteria. The toxic effect can be degraded in two to four weeks. In soil, breakdown may take up to two months. Black walnut leaves may be composted separately, and the finished compost tested for toxicity by planting tomato seedlings in it. Sawdust mulch, fresh sawdust or chips from street tree prunings from black walnut are not suggested for plants sensitive to juglone, such as blueberry or other plants that are sensitive to juglone. However, composting of bark for a minimum of six months provides a safe mulch even for plants sensitive to juglone.
I have black walnut trees as well, and was worried about them, just as you are.
That was 10 years ago, all are fine, both horses and trees.
No need to worry, darn things pop up like bad weeds around here.
The squirrels hiding the walnuts in the ground are a bigger problem
There is just as much horse sense as ever, but the horses have most of it.
My neighbor used to pay her kids a dollar for every 5 gallon pail of walnuts they could pick out of the pasture. Made a nice business for the kids. The horses never suffered from the presence (or absence) of the walnuts.
Re your dead walnut tree. Salvageable for wood? friends who have land up north sold off a bunch of walnut trees to pay for their kids' college. I don't know if you can sell them one-at-a-time but maybe there's a specialty woodworker who'd like to get their hands on it?
I have about 40 trees or so on my 23 acres and have never had a problem. The large nuts DO hurt when they hit you tho'!!! And it confuses the horses if they get clunked on the head.
Walking on the nuts takes some doing and yes I have very happy squirrels!
Post a note on Craigslist if you want to get rid of the nuts. Some people (like me!) would gladly take them off your hands. I've been tempted to stop at people's houses and ask them if they'd mind if I clean up their front yards for them....black walnuts are exquisite! (And very expensive to buy already shelled!)