What Can You Plant Under A Walnut Tree

You can plant plenty of shade-loving plants under a walnut tree, as long as you choose species that tolerate juglone and the tree’s root competition.
 
Walnut trees produce a compound called juglone, which can be toxic to some plants, so not everything will thrive beneath their canopy.
 
But don’t worry, there are still many beautiful and useful options that will grow happily in that spot.
 
In this post, we’ll explore what you can plant under a walnut tree, why juglone matters, and how to give your plants the best start.
 

Why You Can Plant Under a Walnut Tree (And What to Avoid)

You can plant under a walnut tree if you pick species that are juglone-tolerant.
 
The key is understanding how juglone works so you don’t set your garden up for failure.
 

1. Understanding Juglone Toxicity

Juglone is a natural chemical produced by black walnuts and, to a lesser degree, other walnut species.
 
It’s concentrated in the roots, bark, leaves, and nut husks.
 
When juglone-sensitive plants grow near a walnut tree, they may wilt, yellow, or simply fail to thrive.
 
That’s why knowing which plants can tolerate juglone is the first step.
 

2. Root Competition and Shade

Even juglone-tolerant plants face another challenge: the walnut tree’s dense roots and canopy.
 
The roots soak up water and nutrients, and the leaves block a lot of sunlight.
 
So the plants you choose under a walnut tree need to handle both juglone and shade.
 

3. Plants That Struggle Under Walnuts

Avoid planting tomatoes, potatoes, peppers, and eggplants near a walnut tree.
 
These nightshades are highly sensitive to juglone and often die.
 
Other plants to skip include rhododendrons, azaleas, lilacs, and most types of pine.
 
If you try to plant these under a walnut tree, you’ll likely be disappointed.
 

What You Can Plant Under a Walnut Tree

Now for the good news: plenty of plants can thrive under a walnut tree when you choose wisely.
 
Here are some of the best options.
 

1. Shade-Loving Perennials

Hostas are a fantastic choice for under a walnut tree.
 
They love shade and tolerate juglone well, coming back bigger every year.
 
Other perennials you can plant under a walnut tree include astilbe, coral bells (heuchera), and bleeding heart.
 
These perennials add color and texture without fussing over the walnut’s chemistry.
 

2. Ground Covers That Spread

Ground covers are perfect for filling space under a walnut tree where grass won’t grow.
 
Vinca minor (periwinkle), sweet woodruff, and dead nettle all tolerate juglone.
 
They spread steadily and help suppress weeds, making them a low-maintenance option.
 
You can plant ground covers under a walnut tree to create a lush, green carpet.
 

3. Bulbs and Spring Bloomers

Spring bulbs are a smart choice because they bloom before the walnut tree leafs out fully.
 
Daffodils, snowdrops, grape hyacinths, and crocus all do well under a walnut tree.
 
They get enough sun in early spring and then go dormant when the tree takes over.
 
You can plant these bulbs under a walnut tree in fall for a cheerful spring display.
 

4. Herbs for the Shade

Some herbs tolerate juglone and shade, so you can plant under a walnut tree and still harvest fresh flavor.
 
Mint, chives, and lemon balm are reliable choices.
 
Just keep mint in a pot if you don’t want it to take over.
 
You can plant these herbs under a walnut tree in containers or directly in the soil.
 

5. Shrubs That Hold Their Own

If you want something taller, several shrubs tolerate juglone.
 
Try viburnum, arborvitae, or forsythia under a walnut tree.
 
These shrubs provide structure and privacy while handling the tree’s root zone.
 
You can plant these shrubs under a walnut tree along the drip line for a natural look.
 

Tips for Planting Under a Walnut Tree

Even juglone-tolerant plants need a little help to settle in.
 
Here’s how to give them a strong start.
 

1. Improve the Soil First

Walnut trees often leave the soil dry and depleted.
 
Mix in compost or aged manure before you plant under a walnut tree.
 
This boosts fertility and helps retain moisture.
 

2. Water Consistently

Young plants need regular watering to compete with the walnut’s roots.
 
Water deeply once a week, especially during dry spells.
 
Once established, most juglone-tolerant plants will manage on their own.
 

3. Use Raised Beds or Containers

If you’re unsure about juglone levels, you can plant under a walnut tree in raised beds or large containers.
 
This separates sensitive roots from the tree’s root zone.
 
It’s a great way to grow vegetables that might otherwise struggle.
 

4. Mulch, But Don’t Pile It

A layer of mulch keeps moisture in and weeds down.
 
Keep mulch a few inches away from plant stems and the tree trunk.
 
This helps you plant under a walnut tree without encouraging rot.
 

So, What Can You Plant Under a Walnut Tree?

You can plant under a walnut tree if you stick to juglone-tolerant species like hostas, daffodils, mint, and viburnum.
 
Avoid sensitive nightshades and choose plants that handle shade and root competition.
 
With the right picks and a little soil prep, that shady spot beneath your walnut can become a beautiful, thriving garden.
 
So go ahead and plant under a walnut tree with confidence, because the right plants will reward you season after season.