Kalopanax and Juglan ?'s

I finally had a chance to get down to Madison this summer to visit Longenecker Gardens, and was impressed with a couple of trees that I hadn't seen before. The Kalopanax pictum was about 30' tall and wide, and was covered with peculiar looking flowers. The foliage was perfect for this time of year and the overall affect was quite nice. This doesn't seem to be a tree that's gained much popularity and would be interested to hear experience and/or opinions.

The other tree that caught my eye was Juglans nigra 'Laciniata'. I dont have pics of either one of these trees as my camera batteries went dead when I was a considerable distance from the car and I was losing daylight anyway. The cutleaf form on this one was especially attractive and I thought it would make a nice shade tree. Any thoughts on either of these?

Maackia, just keep in mind that the juglone from the black walnut will kill certain plants, trees and shrubs for a very wide area. I've read the effect can be as far as 80 feet from the tree.

That other tree sure is pretty. Apparently it bears fruits that the birds like too.

We talk a lot about invasive species here. If my Kalopanax septemlobus (syn. K. pictus) wasn't probably the largest one in Illinois it would have been toast years ago. I keep ripping out seedlings all over our woods and I keep trying to tell myself that it should stay anyway because it is so unique. But I would never advise someone to plant one, because they spread thousands of thorny seedlings far and fast via those birds that like them so much. I've spoken with several arboretum curators about it, and once they see it they all urge me to keep it as an outstanding display specimen and just continue controlling reproduction. But it gives me nightmares sometimes thinking about what might happen if I lose control over it.
Guy S.

If the walnut produces nuts, that is another consideration too. Think of stoney golf balls falling from the sky, and you'll have an idea of what to expect. So far as the poson in the soil, I used to pooh-pooh the stories I read. Now however, my views are changing.

The hallmarks of walnut poisoning is poor new growth and a rush of the affected plant to set seed. I had a Larix decidua that seemed to be immune to the walnut poison. As the tree got taller and larger, the new growth was measured in fractions of an inch, and the cones became more noticible. Last year was the last year for the tree. At about 15ft/4.5m in height, the tree put out a cone about every 6in/15cm on every branch. Almost no new growth was noted, and this year only a few bottom branches had any new needles this spring. So much for Larix immunity. All the other Pinaceae conifers planted in the walnut vicinity succumb within a few years. This one lasted about 10.

Another victim this year was my prized female American Holly that I grew from seed. At about 10ft/3m, this one lasted as long as it did because of construction. When we trenched alongside the walnut, ~20ft/6m away, large roots were cut. This gave the holly a few years of good growth. About 3 years ago, the holly seemed to have poor spring growth, but I ascribed it to weather conditions. Last year, only about 1/2 the branched made any new leaves, which made for a see-through tree once the 3 yr. old leaves fell. This year, only a few low branches made any new leaves, and the berries can be enumerated with the fingers on my hands.

On the plus side, Prunus species grow right up to the trunk of the walnuts here, and birches also seem immune. Campsis radicans will grow up the trunk if provided with supplemental water to get them established. The grass under the large walnut is fine textured and virtually weed free. No broadleaves like dandelions, plantains or mustards grow there. And one more happy note. Albizia julibrissan grow and bloom well in the shade adjacent to Juglans nigra.

If you find the cut-leaf shape attractive, there is a Rhus (sumac) species with this feature. The one with a yellow leaf, red rachis (Tiger Eye, names like that) is fairly well behaved. After several years of growing well here, I have a small clump with 4 trees, the tallest being about 4ft/1.2m tall. I could do without the yellow, but it briefly turns bright red-orange in the fall, so it is forgiven for the choice of summer color.

Before starting the thread, I checked out the Wisconsin DNR invasive plant list as I had a hunch this might be an issue. Kalopanax is not on the list--at least not yet. I've got to believe that up here would be the far northern reaches of its cold hardiness potential. I've never seen one around and my guess is that winter survival would be tenuous at best. I certainlay don't want to be irresponsible about introducing potentially invasive plants, but I also don't want to pass on an interesting tree that might do very well up here and behave itself ala Magnolia.

Regarding the whole Juglans toxicity issue, I just don't know what to believe anymore. Seems like opinions are all over the board. Pete, it sounds like you are absolutely convinced that the demise of your Larix was due to the toxic affects of the Black Walnut. Is there a list of know affected plants that someone could refer me to? Everything I've read thus far on it seems to be anecdotal. Thanks.

Bob

It's a lot easier to find lists of plants that are tolerant than to find those that are harmed.

I've been trying for 10 years to deal with having several black walnuts in part of my yard. I killed a lot of trees, shrubs and perennials before I found out the problem was the black walnuts. Some will live for several years, they will just never thrive. I moved some of the plants from my flower bed back there this spring that have never done well and was amazed to see them in their full glory for the first time.

Some of the plants on the tolerant list are specific to a variety, too. Coronation Gold yarrow, for example, has done fine. Paprika is one of the plants I moved. It had never grown more than a few inches tall and had never bloomed. This year it's glorious in the other bed.

http://counties.cce.cornell.edu/yates/mg%20articles/MG4.25.01.htm

http://www.ces.purdue.edu/extmedia/HO/HO-193.pdf

http://www.uwex.edu/ces/wihort/landscape/juglone.htm

Bob, keep in mind that most species are added to invasives lists after the horse has left the barn. If it's not yet widely planted up there, it's had no opportunities to escape. It might be just fine for you, but don't place yourself in the position of having a Kalo invasion named the "Macckia Syndrom"! And unlike some so-called invasive plants that just drop seed in the vicinity or send up root sprouts, this one is disseminated by birds.

But if you reaaaally want one despite the risk, come on down and bring your shovel. You can have all you want for free if you promise to kill two more for every one you dig.

Guy S.

Yeah, I wouldn't wanna be the one to let the proverbial horse out of the barn. If one counted all the benefits of growing it vs. potential risks, I suppose it just isn't worth it. The environment seems to be under enough stress; it's not going to kill me to pass on it.

Guy, I have immense respect for your knowledge, credentials, and efforts to educate us on the pitfalls of invasive species. Your 1995 edition of LANDSCAPING WITH NATIVE TREES was one of the very first books I purchased on trees and refer to it often. Still, I can't help but feel (please don't take this wrong) a bit of elitism going on here. It reminds a little of a car commercial where they post a disclaimer on the screen saying "professional driver, don't try this at home." While my knowledge is a pond compared to your ocean, am I not as capable as you to pull unwanted seedlings?

Bob

No Bob, that wasn't my intent and I'm sorry it came across that way. To clarify, if I had known 35 years ago what this tree would do I NEVER would have planted it. Now, because I have this superior example of it here, I feel like the poor lab guy who is responsible for keeping the voucher specimen of smallpox alive for study.

I do walk the adjacent property periodically looking for these durned things, and thus far they seem to be staying within about 1000 feet of the parent tree. But It makes me very nervous because Resin is right. (Resin, how does it behave over there?)

Like I said, it's your choice, and if you feel you have time and energy to deal with the potential repercussions you're welcome to a few hundred of the volunteer seedlings I pull every year.

Guy D.

Guy, I think I understand your reasoning for keeping the Kalopanax. You've got a bona fide arboretum and can reasonably justify keeping a know invasive plant for research/observation purposes. I suspect this is the same reason that the UW Arb/Longenecker keeps the one they've got, which is also a beautiful specimen. My reason for planting one would be merely to satisfy my own interest and curiosity, and that cannot be justified no matter how hard I might try to come up with excuses for planting it. I should add, however, that I am going to try and contact someone at Longenecker about their experience with it, and if it comes out that they've not had any problems with unwanted seedlings it may change my decision. I will certainly take my time with this and collect as much info as possible before even considering planting it.

Resin, we all know you know trees, but it also seems you know a lot about birds. I suppose its only natural that mastery of one leads to knowledge of the other. So, I've got a little test for you: Can you tell me what this bird is and the wood it is carved out of? :)

Hi Guy,

Well, I had to resort to foolery (or just plain foolishness), but I finally got one by you. Its a Mockingbird carved out of Black Walnut. Here's the Nuthatch.

Maackia,

Your carved birds are quite beautiful. Do you have more you can show us?

Here's a pic of the Larix decidua I spoke of earlier. This is from a branch about shoulder high on a tree that was about the dia. of a soda can, dbh. Too bad I didn't listen to the tree and save some seed. Instead, I collected some cones for a wreath last winter and waited for another crop this year. Hah!

My other one is testament to the power of Resin's written word: he killed it with electrons emanating from the computer monitor.
The second tree was planted in the lower field, on a slight hump resulting from the closing furrow of a plow. It was doing fine until he wrote (about 3yrs ago, on another forum, in another universe) that L. decidua was a dry land tree, unlike its American cousin, L. lacinosa. That very year, the wonderful long new growth slowed to a crawl, and this year, the tree died altogether. The fact that the we were in drought conditions for several summers until 3 years ago is purely circumstantial. (That year we returned to normal wet summers.) The fact that the tree had to stand in 8inches/20cm of water for 12 hours this June also doesn't detract from this fact: once the tree knew it wasn't supposed to like the wet clay around its feet, it lost heart and died. This one died without making a single cone, despite being a twin to the one i had planted on dry ground near the walnut.

BTW, I wonder if small doses of juglone could be used to increase cone production. The first conifer I lost near the walnut (Picea pungens) also made some cones before expiring, despite being shorter than I am.

Looks more like Japanese Larch to me, with those strongly reflexed scales.

Hmmmm....., where shall I send my next set of electrons??

Resin