What Plants do Black Walnut Trees Kill

Black walnut trees are a distinctive and beautiful addition to any landscape, but they also have a secret weapon. These trees produce a toxic chemical called juglone, which can kill or inhibit the growth of other plants in the area. If you're planning a garden near a black walnut tree, it's important to know which plants are resistant or susceptible to this chemical.

Plants Resistant to Juglone

Not all plants are affected by juglone, and some can even thrive in its presence. These include:

Black-eyed Susan

Daffodil

Daylily

Hosta

Iris

Lamb's ear

Liatris

Lily of the valley

Phlox

Siberian iris

Snowdrops

Yarrow

If you're looking for flowers or plants to grow near a black walnut tree, these are a good place to start. However, even these plants may struggle if planted too close to the tree or in soil that is heavily contaminated with juglone.

Plants Susceptible to Juglone

There are many plants that cannot tolerate juglone and will either die or struggle to grow in its presence. These include:

Apple trees

Azaleas

Blackberry bushes

Blueberries

Hydrangeas

Lilacs

Raspberries

Rhododendrons

Tomatoes

Walnut trees (including other black walnut trees)

If you're planning a garden near a black walnut tree, it's important to avoid planting these susceptible plants. They will struggle to grow and may die, causing frustration and money wasted on dead plants.

Managing Juglone in Your Garden

If you have a black walnut tree in your yard and still want to grow plants that are susceptible to juglone, there are a few things you can try. One is to plant these plants far away from the tree, at least 50 feet or more. Another is to raise the soil level in the area to dilute the concentration of juglone. You can also try building raised beds with fresh soil or adding organic matter to the area to break down the juglone more quickly.

Remember, even plants that are resistant to juglone may struggle near an established black walnut tree. Make sure to choose plants that are appropriate for the area and soil conditions, and avoid planting anything too close to the tree. With a little planning, you can create a beautiful and thriving garden even with a black walnut tree nearby.