Black Walnut - To plant or not to plant?

Will be moving to a new (old) home on 3 acres. Pretty much a blank slate -- not a tree or shrub on it. Provided I have the appropriate site, should I plant Black Walnuts? They appeal to me because they're beautiful and indigenous to my area. But I'm not certain if their toxicity to other plants should preclude them from a place in my plans. I would welcome advice from those of you who have them -- do you wish you didn't have them or are they treasured citizens? Also, do the nuts significantly ramp up the 'critter factor' in the rest of your landscape?

Include them! They are magnificent and there are many species you can plant underneath them.

Chat,

If you do plant them, plant them in an area that won't be commonly used as part of the outdoor living space. In other words, put them in an out of the way spot. They're fine trees, but I grew up in a yard with 2 mature plants and 2 semi mature plants. When the fruit falls, it's a pain in the neck to clean up. It stains everything that touches them and carries a strong odor when accumulated in large amounts on gloves, etc. They are a double-rake tree (an early drop of leaflets and then the rachises) unless you aren't that particular about what the area under them looks like. I don't remember seeing any caterpillars as a child but in the nursery, we do get a summer crop of them eating the foliage some years. All the above said, the fruit is fine ammuntion for children and I developed a wonderful throwing arm with it. (I had 9 targets, err, brothers and sisters.) If you ever did want to naturally stain anything, build a fire under a cut off 50 gallon drum full of water and walnut hulls (ripe ones) and throw in the object of staining. After about 2 hours of boiling, you'll have a nice, walnut colored object. Kousa dogwood grows fine under them but the one that I planted hasn't flowered and is now into it's 9th year. It is in an awful lot of shade. I planted 1000 or so bulbs of various varieties in my parent's yard and didn't noticed any squirrels out digging them up. I guess if there are enough walnuts to go around, they leave the tulips alone.

Good Luck,
Ernie

These two links have lists of plants that grow under black walnut trees.

http://ohioline.osu.edu/hyg-fact/1000/1148.html
http://www.ppdl.purdue.edu/ppdl/expert/black_walnut_toxicity.html

Agggggggggh The hyperlink won't work. You'll have to type it in.

I'm a nut tree nut, and have plenty of black walnuts planted(but I have nearly 200 acres to work with) - but none in the immediate vicinity of the home or lawn. Most are the last thing to leaf out in spring, and the first to defoilate in late summer, and while there are some significant problems with juglone toxicity, in many cases I think 'failure' of underplanted specimens could just as likely be due to the larger tree, with its well-developed root system outcompeting smaller plants for available moisture and nutrients.

If you're going to put some in, I'd certainly recommend grafted varieties selected for superior nut production, like Thomas Myers, Emma Kay, Clermont, etc. - thinner shells than typical for 'wild-type' BWs, and 2-3 times more nutmeat. Check out the offerings at NRNTN ( www.nolinnursery.com )
There are a few 'ornamental' BW clones - somebody recently posted a photo of 'Laciniata', and I have a serpentine/contorted selection that I'm trialing.

I have lots of mature pecan trees which are similar as far as litter is concerned. I agree with Ernie, the most annoying thing is the leaf rachis (little sticks) that fall to the ground. I bought a lawn sweeper that pulls behind the mower and it gets them up easily.

It sems there are so very many other wonderful trees to plant that I would not go with the black walnut. I find that where mine is almost nothing grows underneath (I said almost nothing) I do have hostas but forinstance the daffodills all along that side do not bloom and even the ground cover (vinca) does not do well. Some might think that is a good thing LOL but just giving an example. They are trashy trees.....if you must plant one I agree with Malus...do it far away from the home.

I gardened under walnuts for 12 years at my old garden before I took them out. I was much happier after I did. I did not have affection for the nuts particularly. The trees were damaged by construction of the road that my house eventually ended up on (though long after the construction of the road...). For me, there are many, many trees which offer better interest in the garden. Walnuts leaf out late, drop foliage early, do not get especially good fall color, shed a lot of twigs and branches. Sure, there are more herbaceous perennials that will grow under them than won't, but when one gets up into the shrub department the list of intolerant shrubs increases. Witchhazels, most members of the rose family, and lots of other woodies do not like the root/drip zone company of walnuts. Why not plant one of the many, many other large woody plants that have more 4 season interest and do noy have the associated problems? I would think differently if you HAD a big walnut and did not want to remove it for its shade. But to plant one, specifically, with the interest of doing other gardening with it? All I can say is that I would never do that, nor recommend that anybody else do unless they were a nut fan and didn't care about any other aspect of gardening.

If you must have them, I also would banish them away from the house where the more 'intense' plantings are likely to be. Then you can have your cake (if you like walnuts, and I don't particularly...) and eat it too.

You could always plant a few northern pecans or some good shagbark or shellbark hickories, if you're into tasty nuts - you'd get nice shade trees, with good fall color(at least on the true hickories) - and less problems with juglone(though the pecan/hickories do produce some, as they're in the walnut family) than if you planted black walnuts. And, the nuts are less messy and easier to crack.

I just paid $1700.00 to remove a large, healthy walnut from my property. They are horrible in a normal yard! Some may tell you that you can plant beneath them. At one time I would have told you that you can plant beneath them, but I've changed my tune. After 3-5 years, things in a walnut's shadow just whither away. Worse, walnuts do not leaf out until June practically, and they lose their leaves in August. Whoa, great, two and a half months of foliage. The tree is always dropping stuff--flowers, leaves, branches, more leaves, and then nuts. The rachis from the leaves wind up in everything. Of course walnuts attract squirrels and chipmunks, and of course walnut seedlings start appearing everywhere. They are hard as heck to pull. And the nuts are a lethal threat. I literally would not let the kids play near the tree in the fall. A walnut from 50' is a danger. The nuts require a lot of effort to enjoy.

Scott

Look at it this way, the zone around a black walnut that affects other plants is 80 feet. Even with three acres, you're going to have huge areas of your property where plants and other trees will be killed or hampered by the juglone.

And once you plant them, the juglone will persist in the soil for years even if you later remove them.

There are much prettier, far less messy trees that provide a lot more shade.

Yes, you can find plants that will survive, but the lists aren't always reliable and you're going to spend a lot of money on plants that are going to die on you.

Hart, is that an 80-foot circle with the black walnut at the center, or 80 feet out from the tree in all directions? We inherited a huge old black walnut in the backyard with this property, and have been very frustrated with things withering away in its shade. I had planned some plantings for the spring in the further reaches of the yard, but don't want to condemn more plants to a slow death. Thanks!

That's 80 feet out from the trunk in any direction. I had no idea when I bought this house 10 years ago what a nightmare it would be trying to grow trees, shrubs, flowers, vegetables anywhere in my huge (acre and a half maybe?) back yard with the black walnuts that were here. Yes, I've found some things that will survive but it sure would be nice to just be able to plant what I want where I want.

Some things will survive for a year or two and then just die. Other things just die right away. So it sometimes takes a few years to find out if a plant really is juglone tolerant or not.

And the walnuts - I remember when I was a kid my mother walking around with black stained hands for weeks from shelling black walnuts. It has to be the messiest, most tedious task I wouldn't wish on my worst enemy. First you have to shell them, then crack them (driving over them with a car doesn't always work), then you have to pick out all the little pieces with a nut pick. And whether you use them or not, you get the lovely task of picking up all those nuts out of the yard.

One of my friends used to say the perfect gift for someone you really dislike is one appointment for fake nails. LOL I think it would be to give them a black walnut tree.

Good grief: there go my plans for the backyard!

Okay, guys, I'm confused. I've been searching online for plants I can successfully put near our inherited black walnut, and there's lots of information out there on species that reportedly do quite well with black walnuts. A couple examples:

http://greenwoodnursery.com/page.cfm/27196

http://www.bhwp.org/native/native_plant_info_sheets/NativeA_Plants_for_Beneath_or_near_Walnut_Trees.pdf

http://www.possibilityplace.com/Tree/detail.asp_Q_CatlD_E_1_A_SubCatlD_E_8_A_ProductID_E_15

Some of these have links to more lists of plants tolerant of juglone. I can see how the tree might be a problem in a small yard, in the sense that it could limit your choices for other plants; but chatnoir started the thread by saying their property is three acres. That surely leaves plenty of room for black walnuts and other plants that may not thrive in their immediate area.

I don't find the litter a big issue; even the rachis rakes up pretty easily. As for the nuts, the squirrels make them disappear in just a couple weeks, and I've not found seedlings coming up from the black walnut. I'd keep the tree just for its value to wildlife, providing food at an important time of year. My only hangup has been to find attractive plants that will survive near it, and it looks like I have plenty of great choices - including lots of attractive natives.

Just my two cents' worth...

Spartacus,

If you're willing to work around them, they're fine plants. I think that personally, I just wanted chat to know that they aren't a carefree, low maintenance plant. I can think of no reason why I wouldn't advise someone of potential reasons they may want to avoid a plant if it may not fit their preferences. Like you said, with 3 acres, there could well be a spot......

Regards,
Ernie

I did a search on 'walnut wilt' and found this from Cornell, also with a very long list of plants that will do fine under a Black Walnut tree
http://plantclinic.cornell.edu/FactSheets/WALNUTW.HTM

With a big enough property, I'd plant them.

Thanks, terryr: now I have even more choices! The backyard may get its home improvement this spring, as I'd hoped...

I wouldn't trust those lists too much. Not one of them agrees with another. Almost all of them are based on anecdotal evidence. Very, very few, if any, comprehensive University scientific studies have been performed. So little is understood that too many questions remain. For instance, it is possible that some walnuts produce more juglone than others. Some walnuts' juglone might be more potent than others. Conversely, if we take a plant from the list posted, Campanula latifolia, some Campanula latifolias might be more resistant to juglone than others. Too much is uncertain, in my opinion, except this: walnuts are not in anybody's list of the top 100 ornamental trees. Anybody who has had one in their yard, even a three acre yard, if they're being honest, will have to concede this. There simply are a ton of better choices, even factoring in a preference for natives, even factoring in a preference for mast producers. Lucky's suggestions for hickories are excellent. Any number of oaks are wonderful choices too. With these trees, you get mast, you get excellent form, good to excellent fall color, foliage retention throughout the season, interesting bark characteristics, little to no allelopathy, and usually one defined season of raking and clean up. Wood is stronger too with less breakage and drop.

As I reported earlier in this thread, I paid a lot of money to remove an 80+ year old walnut. Yes, I will concede, it was beautiful in June and July while it had leaves. By mid-august, it was bare. Fall color: a weak, sickly greenish yellow. The leaves were a constant mess while they dropped because they come down and turn a wet paper brown. After all the leaves had fallen came a blizzard of rachis. No, they aren't difficult to rake if they are in the lawn, but if they are in all of your landscaping, they are an eyesore and they are difficult to remove. They persist for years. In the lawn, they must be raked, they cannot be simply mowed like leaves. They can't be blown with a blower. In spring, the falling flowers were a mess (particularly since I have a nearby swimming pool. They clog the skimmers). There is a falling of aborted nuts in late spring. Then the real nuts in the fall, which are big and messy. The squirrels take the nuts but leave the husks, which stain everything, and smell of the juglone they contain. The squirrels also plant nuts, which in my experience, did come up everywhere in the garden, especially--it seemed--the most difficult places to access. If you simply cut the seedlings off, they come back...for years. They must be dug up or sprayed with Roundup.

Although 3 acres sounds like a lot of land to those of us with standard issue suburban lots, one mature walnut could hold sway over nearly a full acre, or a third of the land, via the juglone produced by its root system. Two remaining acres is plenty for most people to garden, so the decision of whether to dedicate a third or more of the acreage to growing a walnut or walnuts, for whatever reason, is the landowner's to make. But the payback in beauty and wildlife benefit that you get in return for that percentage of land is much smaller than many other trees can provide. If I had three acres, I would not plant walnuts. If I had ten, I wouldn't plant them, necessarily, but I wouldn't cut them down either. If I had twenty, I would probably dedicate an acre to an orchard of them, if for no other reason than for my kids to harvest for lumber in fifty years.

Scott

chatnoir said

very simple

There are lots of better, more beautiful, and just as indigenous plants.

Besides, most of the plants on the Cornell list are not indigenous plants that have evolved in relation to walnuts anyway. In fact, the mentioned daffodils (Narcissus) are listed as growable with walnuts, and they most definitely are not native.

I have gardened ten years in the shadow of an 80 year old, 80' walnut. The lists all say you can't grow azaleas. My azaleas grew fine. Will all azaleas grow fine under walnuts? I don't know. I doubt it, but that's just a hunch. My Viburnum x burkwoodii and V. x juddii grew fine but Viburnum plicatum tomentosum struggled. Roses died. Ilex verticilata (native) died. Pawpaws grew okay, hostas grew okay. It was a lot of hit and miss. It was a lot of wondering and not knowing. It was a lot of things doing okay for a while and then withering away. If you don't wish to garden around a walnut, or don't mind experimenting and losing plants while you do garden around a walnut, go for it. Are there not 100 trees that are more compelling landscape features that don't limit your gardening choices nearly so much? Of course there are.

Scott

This message was edited Feb 23, 2007 1:25 PM

This message was edited Feb 23, 2007 1:32 PM

I just had a tree service out to give an estimate on removing a walnut from my yard, among other things. Hopefully the price is right and I can get rid of it. No evidence of its roots effecting the other trees and shrubs nearby, but the canopy was starting to crowd out and distort the two spruce trees which I would like to keep as an evergreen backdrop to my yard. I totally agree with anything Scott says.

Willis

as do I :~)

Black walnuts have more juglone than regular walnuts and some of the other nut trees like hickories. Which is probably why some of you have no problems growing juglone sensitive plants near regular walnuts. As you can see from this article, having good soil helps too. The soil here is awful.

Some good info in this article from Virginia Tech

Though grown primarily for its wood and nuts, black walnuts are often found growing on landscape sites where they serve primarily as shade trees. When certain other landscape plants are planted near or under this shade tree they tend to yellow, wilt, and die. This decline occurs because the walnut tree produces a non-toxic, colorless, chemical called hydrojuglone. Hydrojuglone is found in leaves, stems, fruit hulls, inner bark and roots. When exposed to air or soil compounds, hydrojuglone is oxidized into the allelochemical juglone, which is highly toxic.

Several related trees such as English walnut, hickories and pecan also produce juglone, but in smaller amounts compared to black walnut. Juglone is one of many plant-produced chemicals that can harm other plants in a process known as allelopathy. (Additional common landscape trees with allelopathic properties: sugar maple, tree-of-heaven, hackberries, southern waxmyrtle, American sycamore, cottonwood, black cherry, red oak, black locust, sassafrass, and American elm.)


Juglone in the soil
Juglone is exuded from all parts of the walnut tree. Juglone can affect other plants either through root contact, leakage or decay in the soil, falling and decaying leaves, or when rain leaches and drips juglone from leaves and branches onto plants below. Plants located beneath the canopy of walnut trees are most at risk because juglone from the roots and fallen leaves accumulates there.

Although juglone has low water solubility and does not move far in the soil, small amounts may be injurious to sensitive plants. Plant roots can encounter juglone when they grow within 0.5 - 0.25 inches from a walnut root. Walnut roots can extend in the soil well beyond the crown or drip line of the tree, affecting susceptible plants far from the black walnut.

The accumulation and depletion of toxins in the soil is affected by factors such as soil type, drainage, aeration, temperature and microbial action. Soil microorganisms ingest allelochemicals as energy sources, and metabolic decomposition can render the chemicals non-toxic to plants. When soils are well drained and aerated, a healthy population of aerobic microorganisms can accelerate this process.

Wet, poorly aerated soil, very common in many urban areas, discourages microbial growth. Plants sensitive to the walnut tree's toxic effect may be at a higher risk when planted in heavy urban soils that lack organic matter. Toxins adhere to organic matter rather than being absorbed by plants, and organic matter also encourages a healthy soil microbial population.

Mycorrhizal fungi are commonly associated with forest tree roots and are considered necessary for normal uptake functions. Allelochemicals can disrupt the uptake process by damaging the root hairs or by inhibiting mycorrhizal populations in the soil. These different soil factors all have an effect on the accumulation or depletion of juglone produced by the black walnut tree.

More at the link including lists of tolerant plants and trees.

http://www.ext.vt.edu/pubs/nursery/430-021/430-021.html

"I totally agree with anything Scott says." ...Willis

"as do I :~)" ...Levilyla

I got my wife, sat her down, and made her read this. It didn't work. I shouldn't have bothered. She still thinks she's smarter than me.

Scott

Well she most likely is...but you are very smart also.

(Giggle.)

Maybe I should sit my wife down and make her read this thread so when she sees the estimate for the black walnut removal, she will understand why.

Willis

This seems to boil down to personal preference, as do so many things in gardening; hopefully we can all respect each other's opinions and, where necessary, agree to disagree. For my own property, I find I'm not willing to take down a tree that has lived far longer than I have, to make my life and gardening more convenient. Simply as a matter of economics, it makes more sense to me to spend a couple hundred dollars, if necessary, to try out plants that are reputedly juglone-tolerant, rather than spend well over a thousand dollars to take down a healthy tree, then wait for the juglone to lose its effect in the soil. But that's just my decision, for my small property. Here's to the differences that make each of us unique...

sparta...I agree with you...I would not spend the money to take down an exisiting large Black Walnut....the original question was from Chatnoir as to whether to PLANT Black Walnuts.. Big difference. Scott is still correct.

Spartacus,

I understand. My wife and I struggled with the decision to remove the walnut for 8 years. It gave a lot of character to the property. In the end we decided as we did, and I have been totally happy with the decision since. But we still might have the tree were it not for the pool. Maybe. I dunno. But pools and walnuts really don't get along well together.

Scott

I am not bashing walnuts here, just my particular one. Mine was obviously planted by some hairy animal, not a comment on the previous homeowner, and is way to close to large Colorado spruces. The canopy of the walnut is now over-topping the smaller spruce and working its way through that spruce causing its leader to lean towards more sun and would eventually cause me to remove the spruce if I let the walnut live. For me it is just a question of one or the other and I choose to keep the spruce as it acts as a nice backdrop to the ornamental trees and shrubs that I have planted.

Equil, for wildlife value would you consider some oaks more important than the black walnut? I realize they all have their own niche in the ecosystem, but just trying to offer other possibilities for large indigenous trees with wildlife value.

Willis-still with Scott on this one :)

I don't think other species have as much difficulty getting along with walnuts as people do...

That said, I'll throw my experiences into the broth frothing here (and pull off a cross-post as well).

There are more than several Juglans nigra growing here at the Valley which came with the property. One reference text lists the following black walnut associates:

•Ulmus americana American elm
•Gymnocladus dioicus KY coffee tree
•Celtis occidentalis Common hackberry
•Fraxinus pennsylvanica Green ash
•Acer negundo Boxelder maple
•Acer saccharinum Silver maple
•Juglans cinerea Butternut
•Tilia americana Basswood
•Carya cordiformis Bitternut hickory
•Cercis canadensis Redbud
•Morus rubra Red mulberry
•Crataegus spp. Hawthorn

I can tell you from personal experience though: Trees don't read books. They don't log in at DG either. There's no better answer than seeing plants coexisting with your own eyes in your own general neighborhood to understand some of these relationships.

I have all of the above (except basswood and butternut). Additional species that are growing here at the Valley together with black walnut include:

•Euonymus atropurpureus Eastern wahoo
•Viburnum prunifolium Blackhaw
•Viburnum rufidulum Rusty blackhaw
•Fraxinus americana White ash
•Fraxinus quadrangulata Blue ash
•Robinia pseudoacacia Black locust
•Catalpa speciosa Catalpa
•Symphoricarpos orbiculatus Coralberry
•Juniperus virginiana Eastern juniper (red cedar)
•Populus deltoides Eastern cottonwood
•Prunus serotina Black cherry
•Platanus occidentalis Sycamore
•Nyssa sylvatica Blackgum
•Salix nigra Black willow
•Quercus macrocarpa Bur oak
•Quercus shumardii Shumard oak
and the classic tire-and-people-friendly
•Gleditsia triacanthos Common honeylocust

If I was to scour around the property instead of just looking out the window...I could probably divine a half dozen (6) more, including several more oaks.

As a really good starting point to determine walnut compatibility, check out distribution maps for where walnuts occur, and see what other species are coincidental. These are plants that "grew up" together.

NOTE: I would venture that there IS some relationship in these associations as to whether a walnut seed and another species' seed hit the ground around the same time and sprouted and grew together (versus a nice big old walnut already firmly ensconced in its juglone soup, and then an interloping species gets introduced to the situation). Sounds like we need a grad student to do a thesis project...

If you have bothered to read this far...I agree with the opinions reflected above concerning introducing Juglans nigra with limited space. I wouldn't do it as a first choice. I don't know that the statement was made, but I think we're talking about a home landscape and not a wildlife refuge. Those are really different circumstances, and choices come down to what the ultimate intent is.

Determine all the different kinds of ways you expect to populate your property with plants (say six times sans spitting). Vegetables, perennials, bulbs, native woodlands, Japanese garden, pool garden, Ailanthus allée, etc. could all come into play. For a long term successful planting, large shade trees (walnuts or others) need to be thoughtfully sited so that the future plantings all get a good shot at coexistence.

With three acres, chatnoir has a lot of options. Introducing black walnut right off the bat (no, wait, that's white ash) would necessarily limit future options without an overall plan. This plant is readily available, establishes relatively quickly in normal soils, and grows rather rapidly in average conditions. What's the rush?

I'm not knocking black walnut except for use as a yard tree. It is nearly at the bottom of the list of trees in terms of that purpose. On a large piece of property, or in the forest, it's a worthy tree that provides for wildlife and belongs in the eco-system. But when a new homeowner asks if they should plant black walnuts in their yard, I feel compelled to point out, from my experience of actually having a large walnut in my yard, A) the high maintenance aspect of the tree; B) the very limited ornamental appeal of the tree; C) the poorly understood allelopathic nature of the tree and how that can and will limit possible future gardening plans with their yard; D) that the tree (when large) can be physically dangerous; and E) that so many other trees are 1) also indigenous; 2) much more ornamental; 3) not allelopathic; 4) not so dangerous; and 5) just as beneficial to wildlife. To not do so would be, in my opinion, irresponsible.

As for the biodiversity of my yard/neighborhood. It is amazing. I am really lucky. There are ten acres across the street that a church leaves as open field, mowing only every second or third year. There is a ton of woods attached and extending away from that (in places, up to three miles). Behind me is at least 50 acres of woods leading to the bottomlands of the protected Little Miami River. We have every bug, bird, bee, amphibian, and mammal imaginable. We had Northern Herriers nest in our back yard a few years ago. And we've got squirrels by the gazillions (which is not necessarily a good thing, by the way). They actually do eat and store the nuts in surprisingly short time. When we had our tree, I would toss the nuts against a chain link fence. In some years there would be a mound of at least ten or fifteen bushes of nuts against that fence. Within three weeks, the nuts indeed would be gone. The nasty, stinky, staining husks would still be there, and a lot of incredibly sharp shards of chewed up hulls, but the nuts would be gone. Yes.

A couple of more things. Cavity nesters are great. I left a big, 20' stump of an otherwise removed silver maple in the back of my yard for just that purpose (and it also serves as a great perch for the numerous raptors in our area). It also is a wonderful support for a climbing hydrangea. But, in the way it is left there, it is not looming over anything or anybody. But a tree that drops large branches that will lead to internal rot is not a practical consideration for most homeowners, even if they've got a soft spot for cavity nesters. Granted, we are discussing the use of this tree in a three acre lot, and not every walnut develops a hollow core (mine did, in places), but, again, three acres isn't quite the same as Smokey Mountains National Park. In fifty to 100 years, possibly less, a walnut will come to dominate almost a third of that property. I just think that is too much of a 3 acre sight to give to a tree with such a laundry list of issues. Again, I find it important to point this out to the poster as information they should consider. If I were asking the question, I'd be appreciative of as many facts, experiences, and opinions, both positive and negative (especially negative), as other participants would care to give me.

Scott

I don't see how anyone could add anymore/different to the last two posts.