I for one found it interesting. Here's a followup question: the area under my black walnut is in deep shade---are your roses are getting at least partial sun?

Thank you for expressing your interest. I didn't think anyone would notice.

Yes they are all getting at least 4 hours full sun per day which is OK for hybrid musk roses. Some are getting more.
The trees or on the Northeast side of my house, so the sun comes up behind them and sets in front of them. I also planted them far enough away from the trunk and at the edge of the tree drip line. So, they get dappled shade most of the rest of the day.

Do you have this issue (juglone toxin) to deal with in Portland? I thought Black Walnut's were mostly an east coast plague.

Forsythia and Sweet Woodruff are both on the lists of tolerant plants. Azaleas and Rhodos are extremely sensitive to the toxin. There are two Azaleas consistantly listed as tolerant - Exbury Hybrids, Gibraltar and Balzac. One other that is sometimes listed is the pinxterbloom azalea.
I cannot tell you how many azaleas I lost before I discovered this problem. And eventhough I moved several to a "safe zone", I still lost them. Squirrels love to plant walnuts!
To be perfectly honest, I hate these trees. They make beautiful furniture and should be farmed by the acre well away from the home landscape. I, however, am surrounded by them, both on my property and my surrounding neighbors' properties. There is no other solution but to fight!

I suspect there may be other Exbury Hybrids that may grow and I intend to try some. Do you know what variety you have? Are they evergreen or deciduous? Exburys are the latter.

The azalea I have that thrives under my black walnut is evergreen, unless my memory is playing tricks on me. I'll make a point to watch it this winter.

Hawkeye Belle -- keep the reports coming! I'll be watching with great interest!

Hellebores, deutzia, phlox, rubeckia, heliopsis, yucca, cornus florida and leatherleaf viburnums are all thriving in the root area of my black walnut. I too loathe this tree except for the fabulous winter shape it makes aginst the sky. Like ink blown by a straw.

Laboopsie, Deutia and Hellebores are new listings to me. Thanks for the info. I am doing a new planting under two more trees that are in shade most of the day. I'll try the Hellebores there.

Always looking for plant information around these trees.

Hawkeye Belle, how are your plants doing now?
I have the same problem and need to find some thing that will perform a little better.
Thanks

Nakara,
All are doing well, so far. The hybrid musk roses all came back and most have buds. Penelope was pruned to the ground due to die back but she is located in a vulnerable position where the winter wind gets her.
I've recently transplanted and planted the following:
2 oak leaf hydrangea, 2 purple leaf plums, 1 Japanese Maple (on partially leafed out-may have been damaged when moved) 2 dwarf forsythia new starts, several pylox, bergenia, hostas, astilbe, geranium,gallium, forget me nots, foam flower, spider wart, ligularia, lamium, ajuga keria hydrangea aboracens. Everything looks ok so far.
The roses do not seem as vigorous as in other locations, but they are healthy and budded.
Thank you for asking!

Hi!
Has anyone had luck with hydrangeas under black walnut trees? I bought some specifically for planting under the row of walnut trees that grows along my driveway, but now I'm not sure what to do. There are lists all over the internet that separate those plants which will tolerate black walnut trees in close proximity and those that will not. Hydrangeas are showing up on both lists. How frustrating.

I have already lost a clematis and some lavendar plants this year. It's my first year at this new house, so I'm blaming the loss on the walnut trees. I don't want to take a chance on losing the hydrangeas as well.

Can anyone comment?

I have hydrangea macrophilia (sp?) aka Big Leaf Hydrangea growing within the root zone of my black walnuts and they are doing just fine. I am experimenting with Oak Leaf Hydrangea but it is too early to tell.
Go for it with the big leaf hydrangea. Hold off on the others unless you are willing to lose. Live and learn.

Thanks Hawkeye! I think I'll give it a try!

Hawkeye Belle, I think I told you on another thread that I was following your example and trying out some roses with multiflora ancestry under my own black walnut trees here in California. After about three months I can report healthy, even vigorous growth on the following roses planted in the root zone of my four trees.

Blue Magenta
Veilchenblau
Rose-Marie Viaud
Danau!
Violette
Aglaia
Rambling Rector
Ghislaine de Feligonde
Treasure Trove
The Garland
Bobbie James

Most of these are once bloomers, so I won't know if they bloom properly for at least a year. Given that they are all ramblers or climbers, it may take a couple of years.

Paula

That is great news Paula. The only one I have is Veilchenblau. I had to move it because of disease. I don't think it got enough sun. It is still within the root zone of the BW and doing fine.

I was wondering about GdF. Such a beautiful rose. Thinking about getting this one. Does your rebloom? No matter; I like her anyway.

Yes, you are right about the length of time. My Paul's HM took three years before I got a decent bloom I think they need to stretch out first. Veil would have given a decent bloom this year but the rabbits did a number on her over the winter.

Thanks for this info.

I have several black walnut trees on the property that affect my gardening. Before I knew better I tried to grow tomatoes nearby! I finally dug them up to see what the problem was. The roots of the healthy tomato plant didn't have walnut roots in the soil below. The tomato plants growing over walnut roots were sickly in proportion to the mass of walnut roots below. When I spaded up the problem area I found it easy to recognize walnut roots by their strong distinctive odor. I had read that the roots stopped at the tree's dripline, but I have found them far out beyond that. Now, when I dig I smell every root I find and make a mental map. For two years I watered the tomatoes that thrived and skipped the sickly ones. Eventually the walnut roots grew into the soil with more moisture and I moved my tomato garden. Other plants, like a Niko Blue Hydranga have survived and even grown a little but have never bloomed. So, I judge that susceptability to Juglan Poisening varies not only from spcies to species but other factors as well. In fact, some plants (Kentucky Bluegrass, Eastern Hemlock) apparently thrive especially well on juglans. I wish I had a list of those that thrive, those that merely hang on, and those that die right away! Interesting plants cost too much (time especially) to test one by one, one year each, under a walnut tree. I'd also like to figure out what influences the direction the tree roots grow since they all seem to grow on hillsides. And, how deep do they grow? Can I put shallow rooted plants under walnut trees?
Any answers from your experience would be so very, very welcome! For example, Hellebores don't seem to be on any list I know about. can they thrive with juglans? I didn't start this thread, but my email address is "luellen@earthlink.net.

There are many lists. I've give you a link to one. If you want more info. do a google search on Juglon Toxin or Black Walnut Poisen.
I have a Niko Blue thriving. Check out your plant and see if there is another reason it did not bloom. When did you prune it?
At first, I had a tendancy to blame all my failures on the BW tree. Now, I've just learned how to cope with it.

Tomatoe plants are the test for juglon infected soil. I am surrounded by 9 trees. Yet, there is a tomato volunteer in the center of one of my borders. I know that soil is juglon free.

Good luck!

Here is a link that might be useful: Landscape Juglone Tolerant Plants

I live in a windy area and I believe I have California Black Walnut trees. Until I found this site, I thought the only plant that would grow under black walnut was ivy. Good to know that there are other plants as well. Any suggestions for plants that can grow under the black walnut as well as in a windy area?

Organic joans, Try hostas, astilbes, some ferns like cinnamon ferns, day lilies, monada, spider warts, shasta daisies, siberian iris, toad lilies, aguga, kerria japonica and the aboracens hydrangea, Annabelle. Keep them well watered as the soil beneath any tree is often very dry.

Hope this helps.
Barbara

Trying to cross-index for juglone resistance and resistance to deer and rabbits..doesn't leave much besides lambs ears,poison ivy and garlic chives.
The Dahoon holly I carefully planted away from the root zone in soil 3 feet above the level of the soil where the BW is located and now, three years later, the dahoon is showing tip leaf yellowing.
For all I know, there might have been a BW cut down when the lot was cleared below the dahoon location or the squirrels may be burying the nuts there.
It's very frustrating.

A question..I notice that the BW trunk and branches get almost black in rainy weather and now I note three or four with similar darkness in the other parts of the forest close to the yard.
Cutting these down and killing the roots is in the plan. Will I ever be able to plant at will or is removing all the roots necessary?

I'm new to this BW intolerant plant info. Planted to white hydrangeas two yrs ago. They died. This forum is so helpful. I will now try big leaf hydrangea. I hope it comes in white and is similar to the mop heads I planted. So far the cone flowers are ok, not thriving. I'll do a better job of checking the varieties on my plants. Also my forsythia is thriving along with the dayliies, bearded iris, pachysandra.

This post was edited by Diana195011 on Mon, Jul 21, 14 at 12:36

A black walnut may not kill a rose immediately but exposure to juglone will definitely stunt its growth and limit its lifespan.

I have had the same issue with the native pecan trees, in Texas. The oak leaf hydrangea lasted three years. I love roses, but haven't tried them, yet. I didn't want liriope, but it moved in, and is doing quite well, much to my chagrin. But I have a thing about removing living things, so there they are! 😀 I've experimented with several native plants, and have found that yaupon, Turk's cap, (aka Mexican apple) does well, as do Christmas fern, St. John's wort, and artemisia. Daffodils, lily of the valley, and bearded iris have survived thirty years, with absolutely no help, as have the rosemary bushes. Oak trees, redbuds, and Eve's necklace have been next to the pecan trees, for thirty, to fifty years. Sadly, the mints, bee balm, and lemon balm only made it two years. On the upside, I've seen non-natives that have survived at least twenty-five years, such as Japanese boxwoods, nandinas, and ligustrums. The gardenia bush died within three months, even though I pampered it. Juglone is a real bugger, but the pecan tree is our state tree, the birds love them, and they provide a squirrel circus that is often hilarious! Loved your article, Hawkeye_Belle! I love roses so much, and I've spent thirty years wondering whether my pecan trees would do them in. You've provided some excellent information!

Hi Hawkeye_Belle, i just found this post after 18 years of your first post. i am just wondering how is the Roses now?

I have old garden peonies that have thrived for decades near black walnut. Other plants that have done well are ligularia, cimicifuga, phlox, sedum Autumn Joy, barberry, iris, pulmonaria, Ostrich fern, Lady in Red fern, astilbe, bleeding heart, narcissus, anemone Robustissima. I am in Zone 5, Ontario. i also have a Cornus Kousa Summer Gold that is doing as expected for three years. No luck with echinacea White Swan or Cheyenne Spirit, phystotegia, Fairy rose, salvia.

Hi Marsha, thank you so much for your information. i am in Ontario too, zone 4B or 5. in Kanata, actually. So, i think i have to move my Chayenne spirit. that’s why they look so skinny as well as Black Eyed Susan. How about Roses? have you ever tried growing other Roses except Fairy? thank you Marsha.

Hi Double Begonia :), I haven’t tried any other roses there except for the Fairy. I contacted David Austin Roses to inquire. They would not recommend any. i am surprised that black eyed Susan does not do well. Connon Nurseries website has a list of juglone tolerant plants. iI think the echinacea purpurea (species) is listed as tolerant. I had hibiscus that lived for awhile. Poppies come back. Allium seem okay. All of my roses have been in decline over past few years, I think due to a lot of insect damage.

Can you reccommend thrivingn plants I haven’t mentioned?

Hi Marsha, thank you so much for your feedback. i have Nova Zembla Rhoddies and Purple one, it’s been 3 years and they are doing ok. they are about 15 ft frm BW. others are Coreopsis, Giant Lily (so healthy), Iris never bloom, Veronica speedwell - so healthy and flourish, Daylily survive, Bridal Wreath spirea is so slow as well as Rose of sharon, so slow. i have another 3 roses and they are still ok and blooming. maybe because I planted them this year and i trimmed the BW branches so we get more sun in our backyard. the BW is in my neighbor property. oh ya, Clematis died. :( when i knew that my neighbor tree is BW , i mourned for 3 weeks . but now I am letting it go and do some trial and errors.