What Can You Plant Under A Walnut Tree

You can plant plenty of shade-loving plants under a walnut tree if you choose species that tolerate juglone, the natural chemical walnuts produce.
 
Walnut trees release juglone from their roots, leaves, and husks, and this substance can stunt or kill sensitive plants nearby.
 
But that doesn’t mean the space beneath a walnut tree has to stay bare.
 
If you’ve been wondering what you can plant under a walnut tree, the good news is that many vegetables, flowers, and groundcovers grow happily in that dappled shade.
 
In this post, we’ll look at why planting under a walnut tree is tricky, which plants you can safely grow, and how to set them up for success.
 
Let’s dig in.
 

Why Planting Under a Walnut Tree Is Tricky

The challenges of what you can plant under a walnut tree come down to a few key factors.
 
Once you understand them, choosing the right plants gets much easier.
 

1. Juglone Toxicity

Juglone is a compound that black walnuts and other walnut species release into the soil.
 
It’s the main reason some plants wilt, yellow, or simply refuse to grow when you plant them under a walnut tree.
 
Juglone builds up in the soil and affects sensitive plants within the root zone, which extends well past the canopy.
 

2. Heavy Shade and Dry Soil

Walnut trees also cast deep shade and pull a lot of moisture from the ground.
 
Even plants that tolerate juglone can struggle if they’re thirsty and sun-starved.
 
So when you’re deciding what you can plant under a walnut tree, pick species that handle both shade and dry conditions.
 

3. The Root Zone Matters

Juglone concentrations are highest near the trunk and taper off as you move outward.
 
That means the further you plant from the trunk, the more options you have for what you can plant under a walnut tree.
 

What You Can Plant Under a Walnut Tree

So, what can you plant under a walnut tree without watching it struggle?
 
Here are the categories that work best.
 

1. Shade-Loving Vegetables

Several vegetables shrug off juglone and grow well in the shade of a walnut tree.
 
Beets, carrots, onions, parsnips, and squash are all solid choices.
 
You can also plant beans, corn, and melons under a walnut tree as long as they get enough water.
 
Just avoid tomatoes, peppers, eggplant, and potatoes, which are all sensitive to juglone.
 

2. Juglone-Tolerant Flowers

You can plant a range of flowers under a walnut tree, and they’ll add color to that shady spot.
 
Good picks include hostas, daylilies, astilbe, ferns, and bleeding hearts.
 
Violets, pansies, and columbine also do well under a walnut tree.
 
These perennials come back year after year and handle the juglone without complaint.
 

3. Berries and Fruit

You can plant certain berries under a walnut tree, including black raspberries and elderberries.
 
Cherries, blackberries, and currants also tolerate juglone reasonably well.
 
Avoid apples and pears, though, since they’re sensitive to it.
 

4. Groundcovers and Herbs

Low-growing groundcovers are a smart way to fill the space when you plant under a walnut tree.
 
Try creeping phlox, wild ginger, or vinca for a green carpet that needs little care.
 
For herbs, you can plant mint, chives, and oregano under a walnut tree.
 
These spread nicely and cope with the shade and juglone without much fuss.
 

How to Plant Successfully Under a Walnut Tree

Knowing what you can plant under a walnut tree is half the battle.
 
The other half is giving those plants a fighting chance.
 

1. Amend the Soil

Mix in plenty of compost before you plant under a walnut tree.
 
Rich, organic soil helps dilute juglone and gives roots the nutrients they need.
 

2. Water Regularly

Walnut trees compete hard for moisture, so water your plants often.
 
Consistent watering keeps stress low and helps plants cope with juglone.
 

3. Keep Plants Away From the Trunk

Plant at the outer edge of the canopy, where juglone is weaker.
 
This gives whatever you plant under a walnut tree the best chance to thrive.
 

4. Mulch, But Carefully

A layer of mulch helps retain moisture and suppress weeds.
 
Just keep it a few inches away from the trunk to avoid rot.
 

So, What Can You Plant Under a Walnut Tree?

You can plant many shade-tolerant, juglone-resistant species under a walnut tree, from beets and beans to hostas and elderberries.
 
The key is choosing plants that handle juglone, shade, and dry soil, then giving them rich soil and steady water.
 
Avoid the sensitive nightshades like tomatoes and peppers, and plant toward the outer edge of the root zone.
 
With the right picks, the ground under your walnut tree can be just as productive as any other part of the garden.