What Can You Not Plant Near A Walnut Tree

You can’t plant certain things near a walnut tree because the tree releases a chemical called juglone that’s toxic to many plants.
 
This natural herbicide builds up in the soil around the walnut’s roots and can kill or stunt sensitive vegetables, flowers, and even some trees.
 
So if you’ve been asking what you cannot plant near a walnut tree, you’re in the right place because the list is longer than most gardeners expect.
 
In this post, we’ll go over the plants you can’t plant near a walnut tree, explain why juglone causes so much trouble, and share a few tips for gardening around black walnuts without losing your whole harvest.
 
Let’s dig in.
 

Why You Can’t Plant Certain Things Near a Walnut Tree

The reason you can’t plant certain things near a walnut tree comes down to juglone.
 
Here’s why that matters so much.
 

1. Juglone Is a Natural Toxin

Black walnuts produce juglone in their roots, leaves, bark, and nut hulls.
 
This compound is the main reason you can’t plant many garden favorites near a walnut tree.
 
Juglone interferes with a plant’s ability to take up water and nutrients, which causes wilting, yellowing, and sometimes death.
 

2. The Roots Spread Far and Wide

Walnut roots can stretch well beyond the tree’s canopy, often two to three times the drip line.
 
That means you can’t plant a veggie patch near a walnut tree even if it looks far enough away.
 
The toxin moves through the soil wherever those roots travel.
 

3. Leaves and Hulls Add to the Problem

When leaves fall or hulls break down, they release even more juglone into the ground.
 
That’s another reason you can’t plant delicate seedlings near a walnut tree without seeing damage.
 
Composting walnut debris only spreads the toxin further.
 

4. Sensitivity Varies by Plant

Some plants tolerate juglone, but many can’t handle it at all.
 
So what you can’t plant near a walnut tree depends partly on how sensitive each species is.
 

Vegetables You Can’t Plant Near a Walnut Tree

If you’re wondering what you can’t plant near a walnut tree in the vegetable garden, this list will help.
 
These crops are famously juglone sensitive.
 

1. Tomatoes

You can’t plant tomatoes near a walnut tree without risking stunted growth and wilted leaves.
 
Tomatoes are one of the most juglone-sensitive vegetables out there.
 

2. Peppers and Eggplants

Peppers and eggplants also struggle, so you can’t plant them near a walnut tree if you want a healthy harvest.
 
They’ll often yellow and stop producing fruit.
 

3. Potatoes

You can’t plant potatoes near a walnut tree either, since juglone causes poor tuber development.
 

4. Peas and Beans

Legumes like peas and beans are sensitive too, so you can’t plant them near a walnut tree without trouble.
 

5. Cabbage and Other Brassicas

Cabbage, broccoli, and cauliflower round out the list of veggies you can’t plant near a walnut tree.
 

Flowers, Shrubs, and Trees You Can’t Plant Near a Walnut Tree

The list of what you can’t plant near a walnut tree goes well beyond veggies.
 
Here are some ornamentals and woody plants to avoid.
 

1. Azaleas and Rhododendrons

You can’t plant azaleas or rhododendrons near a walnut tree because they quickly wither under juglone stress.
 

2. Peonies and Lilacs

Peonies and lilacs also suffer, so you can’t plant them near a walnut tree if you want them to thrive.
 

3. Apples and Pears

You can’t plant apple or pear trees near a walnut tree without risking poor yields.
 

4. Silver Maples and Birches

Silver maples and birches are also sensitive, so you can’t plant them near a walnut tree.
 

5. Petunias and Other Tender Annuals

Most tender annuals, including petunias, won’t survive, so you can’t plant them near a walnut tree.
 

What You Can Plant Near a Walnut Tree Instead

The list of what you can’t plant near a walnut tree is long, but the tolerant list is decent too.
 
Try these instead of the sensitive plants above.
 

1. Most Grasses and Some Ground Covers

Tall fescue and many native ground covers handle juglone well, so they’re safe options when you can’t plant other things near a walnut tree.
 

2. Beans That Tolerate Juglone

Some snap beans and lima beans tolerate it better than others, though results vary.
 

3. Hardy Perennials Like Daylilies

Daylilies and hostas often hold up, giving you color where you can’t plant fussier flowers near a walnut tree.
 

4. Raised Beds and Containers

If you truly can’t plant in the ground near a walnut tree, raised beds with fresh soil and a liner can solve the problem.
 

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

You can’t plant tomatoes, peppers, potatoes, peas, beans, cabbage, azaleas, rhododendrons, peonies, lilacs, apples, pears, birches, and many tender annuals near a walnut tree.
 
The reason is juglone, a natural toxin the tree releases through its roots and debris.
 
This chemical makes it impossible for many sensitive plants to survive, no matter how well you care for them.
 
If you remember what you can’t plant near a walnut tree and stick to tolerant species, you can still enjoy a healthy garden.
 
So now you know what you can’t plant near a walnut tree.