Ideas for replacing a walnut tree with plants that are resistant to Juglone toxicity.

If you’ve ever removed a Black Walnut tree from your yard and have found that very few plants will grow in its place or the ones that do grow grow very poorly, the problem is generally due to a chemical that Walnut trees produce called Juglone.

Even if you’ve removed the tree completely and it has been gone for years, you may still find that plants still have a hard time growing. Some folks find than even if they replace the top soil several inches deep, the new plants still show signs of Juglone toxicity. The problem here is that until any remaining roots have completely decomposed, there will still be traces of the chemical in the soil.

The solution to getting plants to grow in the effected bare area in your yard may be to use plants that are resistant to Juglone toxicity. Many annuals will do well as will these in the following list.

Juglone Resistant Plants

The following perennials, shrubs, and bulbs are generally resistant to Juglone toxicity.

Shrubs

• Rose Of Sharon Hibiscus
• Japanese Maple
• Spirea

Bulbe

• Crocus
• Tulips
• Daffodil

Perennials

• Astilbe
• Columbine
• Coral Bells
• Daylily
• Spiderwort
• Yarrow

If you have Black Walnut trees or plan to plant them in your landscaping, keep in mind that roots will generally go to or slightly past the drip zone of the trees. You shouldn’t plan to have any gardens, lawn, or landscaping plants in the area. Root barriers like driveways or sidewalks may help as separators as long as leaves, nuts, and other tree debris aren’t allowed to settle in desirable growing areas.

More Resources and Juglone Resistant Plant Ideas

Black Walnut Toxicity

Black Walnut Toxicity to Plants, Humans and Horses

About Juglone From Wikipedia

Aside from genetics, poor soil conditions are usually the main cause of surface roots. While compacted soil is the problem in most cases, the presence of toxins, low oxygen, and too much or not enough water are also causes. Deep watering may or may not make a difference in some cases. If so, it’s most likely due to the water keeping the deeper soil loosened. Regardless, trees and most plants like infrequent deep watering rather than frequent shallow watering so this should be common practice anyway. Again, it may or may not make a difference.

While trees do send out tap roots for stability and some roots deeper for moisture and feeding, most feeder roots grow at the surface few inches of soil. And just as the trunk and the branches of the tree grow wider as they get older, so do the roots. So eventually, some of these shallow older roots will naturally grow out of the soil. Sometimes the roots will also become visible because of erosion of the surface soil.

Once the roots appear on the surface, there is little that can be done to get rid of them without hurting the tree. You can possibly prune off the visible roots but the damage to the cut roots and the fine feeder roots surrounding the area can harm or even kill the tree. Pruning the roots should be limited to situations where the roots are breaking foundations, sidewalks, driveways, and anything they shouldn’t be.

There are a few common approaches to “dressing up” top root areas. However, due to these surface roots becoming like hardwood as they grow out of the soil, you have to be careful covering them or they could possibly get a fungus, disease, or rot. The best cover is a few inches of course mulch or bark chunks. Finer mulches are usually o.k. but don’t allow as much air circulation around the roots.

Be creative. Build a small retaining wall or edging around the area to contain the mulch and create a planting bed. Add some ground cover plants and the problem disappears while adding a new dimension to your yard and landscape.

One last thing. While I have also seen a few instances where the areas were successfully filled over with good soil and replanted or sodded, I don’t personally advise it. Just as burying a trunk of a tree can cause the outer surface bark to become soaked, soft, weak, and diseased, it can also have the same effect on the hardwood bark of the surface roots. And if it does work it’s usually only temporary as eventually the roots grow to the top surface again.

While ideas for desert landscaping are often thought of as being the same as xeriscaping, it isn’t necessarily always true. Xeriscaping is actually a set of principles and methods for creating water wise landscapes and gardens regardless of style. Still, when a client tells me they want a xeriscape design, most times they really mean they want a landscape or garden that is of the desert Southwest nature. So today, more often than not, xeriscaping and desert landscaping ideas are referred to as the same design style.

Xeriscaping Principles And Methods

For the sake of the perceived meaning of xeriscaping, most of the pictures, ideas, and plans in this post represent a southwest desert landscaping style. However, for a technical understanding and the true benefits of xeriscaping, it’s first important to get an understanding of the true meaning and applications of xeric principles. See Xeriscaping Principles And Ideas. You will also find more good pointers and different ideas at Xeriscape Colorado and Xeriscape NM .

While the phrasing may be different from explanation to explanation, the basics of xeriscaping are all the same and very simple to use. Grouping plants, creating rich organic soil, terracing, and other low water use practices are simple common sense but aren’t considered into most landscape or garden design. With today’s awareness for the need of green earth friendly living, xeriscape principles should be a consideration in all new landscaping and garden designs.

Southwest Desert Ideas And Pictures

Again, while xeriscaping can be applied to most any landscaping or garden design style, it is most often applied to Southwest, Desert, Santa Fe, and Arizona styles. See –

Xeriscaping Ideas And Pictures
A collection of Southwest desert Santa Fe landscape design photos, ideas, and plans.

xeriscaping ideas
A collection of some of my own design ideas and plans.

Xeriscaping Plans
A collection of some the best xeric, desert, Southwest, and low water use design plans and ideas from other designers and sources on the web.

Southwest Landscaping

See Desert Southwest Landscaping ideas for a collection of other designers and plans applied to xeriscaping landscapes and gardens.

Here’s some interesting xeriscape desert design ideas in a front yard design we created on a slope.