Homestead mailing list

[Gene GeRue <genegerue AT ruralize.com>]

On Jun 10, 2008, at 7:30 PM, EarthNSky wrote:

> It is my understanding that juglone is in all parts of the tree, so as
> the leaves and fruits fall and decompose, you release limited  
> amounts of
> it into the soil, with the heaviest concentration logically under the
> tree.  I'd bet that only downwind/downslope plants are affected, where
> the leaves fall..  probably in very windy locations, there is minimal
> effect, only from roots, and that might be why some folks don't seem  
> to
> have as many issues as others.  I have black walnuts in my pasture and
> grass grows under them the same as the neighboring poplars.  There  
> is a
> persimmon which always fruits heavy within 20 feet of the walnut..what
> plants again did you say were affected?

My personal losses include apple, tomatoes and basil. Some other  
problem plantings may have been affected and I didn't know the cause.  
My research thus far says that roots contain the most juglone. The  
apples I have lost were well beyond the drip line of the one big tree  
that is the main culprit, I think, like a hundred feet from the tree  
trunk. They were uphill and upwind from the tree.

Here is the list I have so far--not sure if it will send intact as it  
has lines around it:

Plants Sensitive to Juglone

Plants Tolerant of Juglone

Vegetables: cabbage, eggplant, pepper, potato, tomato

Vegetables: lima beans; snap beans; beets; corn; onions; parsnips;  
melons; carrots; squash; beets;

Fruits: apple, blackberry, blueberry

Fruits: Black raspberry, Peach, Nectarine, Cherry, Plum, Pear

Landscape plants: black alder (Alnus); azalea; basswood; white  
birches; Hopa crabapple*; hackberry; Amur honeysuckle; Japanese larch;  
lespedeza; lilac; saucer magnolia; silver maple; mountain laurel;  
loblolly pine; red pine; scotch pine; white pine; potentilla; privet;  
rhododendron; Norway spruce

Landscape plants: red cedar; crabapple*; elm; winged euonymus;  
forsythia; hawthorn; hemlock; hickories; black locust; most maples;  
oaks; autumn olive; pachysandra; pawpaw; persimmon; wild rose;  
sycamore; most viburnums; Virginia creeper

Flowers & herbaceous plants: autumn crocus (Colchichum); peony

Flowers & herbaceous plants: bluebells; Kentucky bluegrass; daffodil;  
daylily; ferns; fescue; iris; Jack-in-the-pulpit; liriope; narcissus;  
phlox; poison ivy; Shasta daisy; trillium

Field crops: alfalfa; crimson clover; tobacco

Field crops: white clover; red top grass; orchard grass; soybean;  
timothy; wheat

*Published sources contradictory on crabapple's sensitivity to juglone.