What Can You Not Plant Near A Walnut Tree

You cannot plant certain vegetables, fruits, flowers, and shrubs near a walnut tree because of a toxic compound it releases called juglone.
 
This natural chemical is produced in the roots, leaves, bark, and nut hulls of walnut trees, especially black walnuts.
 
If you’ve been wondering what you can’t plant near a walnut tree, the answer is a pretty long list.
 
So before you grab your shovel and seeds, it’s worth knowing which plants will struggle or flat-out die near a walnut tree.
 
In this post, we’ll go over what you cannot plant near a walnut tree, why juglone is such a problem, and which plants actually tolerate it.
 
Let’s dig in.
 

Why You Can’t Plant Just Anything Near a Walnut Tree

The main reason you can’t plant just anything near a walnut tree comes down to juglone toxicity.
 
Juglone is a allelopathic compound, which means it’s a chemical released by one plant to suppress the growth of others.
 
It’s the walnut tree’s way of reducing competition for water, nutrients, and sunlight.
 
The highest concentration of juglone is found in the roots, but it’s also present in leaves, buds, and nut hulls.
 
When it rains, juglone leaches into the soil and can spread as far as 50 to 80 feet from the tree’s trunk.
 
That’s a huge area where sensitive plants simply won’t thrive.
 
So if you’re asking what can you not plant near a walnut tree, the safe answer is: most things that are sensitive to juglone.
 

Vegetables You Cannot Plant Near a Walnut Tree

Vegetables are some of the most sensitive plants when it comes to juglone.
 
Here are the ones you should definitely keep away from your walnut tree.
 

1. Tomatoes, Peppers, and Eggplants

Tomatoes, peppers, and eggplants are all members of the nightshade family, and they’re extremely sensitive to juglone.
 
Planting them near a walnut tree often leads to stunted growth, yellowing leaves, and poor fruit production.
 
Many gardeners report that their tomato plants simply wilt and die within weeks.
 
So if you’re wondering what can you not plant near a walnut tree, these three are at the top of the list.
 

2. Potatoes

Potatoes are another vegetable you cannot plant near a walnut tree.
 
They’re very susceptible to juglone and often develop brown, curled leaves and tiny tubers.
 
Even if they do grow, the yield is usually disappointing.
 

3. Cabbage, Broccoli, and Cauliflower

Members of the brassica family, like cabbage, broccoli, and cauliflower, also struggle near walnut trees.
 
They tend to grow slowly and produce small, weak heads when exposed to juglone.
 

4. Peas and Beans

Peas and beans are legumes that fix nitrogen in the soil, but they don’t tolerate juglone well.
 
Planting them near a walnut tree often results in poor germination and stunted vines.
 

5. Asparagus and Rhubarb

Asparagus and rhubarb are perennial vegetables that you cannot plant near a walnut tree.
 
They may survive for a season or two, but they’ll gradually decline and produce very little.
 

Fruits, Flowers, and Shrubs You Cannot Plant Near a Walnut Tree

It’s not just vegetables that suffer.
 
Many fruits, flowers, and shrubs are also on the “do not plant” list near walnut trees.
 

1. Apples, Pears, and Peaches

Apples, pears, and peaches are fruit trees that cannot be planted near a walnut tree.
 
They’re sensitive to juglone and often develop poor growth, small fruit, and dieback.
 

2. Blueberries and Blackberries

Blueberries and blackberries are also sensitive to juglone.
 
They may survive but will produce far less fruit than they would in a juglone-free spot.
 

3. Azaleas, Rhododendrons, and Lilacs

Azaleas, rhododendrons, and lilacs are flowering shrubs that you cannot plant near a walnut tree.
 
They often show signs of wilting, yellowing, and eventual death when exposed to juglone.
 

4. Peonies and Chrysanthemums

Peonies and chrysanthemums are also on the sensitive list.
 
They may come back year after year but will be weak and produce fewer blooms.
 

What You Can Plant Near a Walnut Tree Instead

If you’re wondering what can you not plant near a walnut tree, it helps to also know what actually works.
 
Some plants are juglone-tolerant and can grow near walnut trees with little issue.
 
These include:
 
– Most grasses and lawn turf
 
– Beans like lima beans and snap beans (some varieties tolerate it better)
 
– Corn
 
– Onions and garlic
 
– Carrots and parsnips
 
– Melons and squash
 
– Most ornamental grasses
 
– Daylilies and hostas
 
– Ferns and wild ginger
 
– Cherry, plum, and black raspberry (these are more tolerant than most fruits)
 
So while the list of what you cannot plant near a walnut tree is long, you still have options.
 
Just be sure to plant tolerant species and give them plenty of space.
 

So, What Can You Not Plant Near a Walnut Tree?

You cannot plant juglone-sensitive plants like tomatoes, potatoes, peppers, eggplants, cabbage, peas, beans, apples, pears, peaches, blueberries, azaleas, rhododendrons, lilacs, peonies, and chrysanthemums near a walnut tree.
 
These plants will struggle, produce poorly, or die because of the juglone toxin released by the walnut tree’s roots and leaves.
 
If you want a thriving garden near a walnut tree, stick to juglone-tolerant options like corn, onions, carrots, squash, melons, and most ornamental grasses.
 
Now that you know what you cannot plant near a walnut tree, you can plan your garden with confidence and avoid the heartbreak of watching your favorite plants wither away.