Walnut trees are absolute giants in the garden, reaching impressive heights and spreading their branches wide. Because of this, they usually need plenty of elbow room. However, if you’re dreaming of filling that empty space underneath one, it *is* possible with the right approach. Let’s dive into which plants can actually handle living under a walnut tree.
The Walnut Tree: A Natural Loner
In the gardening world, the walnut tree is a bit of a “loner.” It generally prefers to stand solo rather than rubbing shoulders with other trees or shrubs. This isn’t just because of its massive size, though. The real secret lies in a chemical called juglone. Walnut leaves produce this natural growth inhibitor, and when it rains, the juglone washes off the leaves and into the soil, effectively stopping many other plants in their tracks.
It’s not just the leaves, either—the roots release their own growth-stunting substances too. Combine that with the fact that those thick walnut roots hog all the water and the dense canopy blocks out most of the sunlight, and you’ve got a pretty tough neighborhood for most plants.
Making Underplanting Work
Don’t lose hope just yet! You can still try underplanting if you’re up for a little extra garden TLC. The trick is picking the right species and staying on top of maintenance. You’ll need to make sure your smaller plants are getting plenty of extra water and nutrients since they’re competing with a giant. It’s also super important to rake up fallen leaves quickly so those growth inhibitors don’t soak into the ground.
One more tip: when it’s time to harvest your walnuts, be careful not to trample your beautiful new groundcover!
The Best Plants for the Job
If you want to plant under a walnut tree, you need “tough-as-nails” plants that love the shade and aren’t bothered by the tree’s natural chemicals.
Here are a few great candidates that can hold their own:
- Robust Ferns: Options like Wood Fern or Ostrich Fern are hardy enough to handle the conditions.
- Hostas: These shade-lovers work well, but here’s a pro tip: plant them in pots and then sink those pots into the ground. This helps shield their roots from the tree’s chemical defenses.
- Periwinkle (Vinca): A tough, evergreen groundcover that can handle the competition.
- Bergenia (Pigsqueak): These are great because they are very tolerant of the soil conditions found under walnuts.
- Wood Anemones: These are perfect because they bloom early in the spring, getting their sunshine fix before the walnut tree fully leafs out and casts deep shade.
