So you’ve just had a tree removed and the stump ground down. Now you’re left with a pile of wood chips and shredded material. You might be wondering what to do with stump grindings. This material is a fantastic resource, not waste, and I’m here to show you some of the best ways to use it.
What To Do With Stump Grindings
Stump grindings are the mix of wood chips, shredded bark, and soil left behind after a stump is mechanically ground. It’s a coarse, chunky material that decomposes slowly. This is actually a benefit for many garden uses. Before you use them, check for any large root pieces or stones and remove them.
Top Uses for Stump Grindings in Your Garden
These ideas will help you put that pile to good work right away.
- Mulch for Trees and Shrubs: This is the most common and effective use. Spread a 2-4 inch layer of grindings around the base of trees, shrubs, and in perennial beds. It suppresses weeds, retains soil moisture, and regulates soil temperature as it breaks down.
- Pathway Material: Create natural, rustic garden paths. The grindings compact well over time and provide excellent drainage. Just lay down a weed barrier fabric first, then add a 3-inch layer of grindings. They’ll need topping up every year or two.
- Fill for Low Spots: Got a dip in your lawn or garden? Stump grindings are perfect for filling it. Tamp them down firmly. Because they decompose, the fill will settle significantly, so mound it higher than you need and let it sit for a few weeks before adding topsoil and sod or seed on top.
Creative Projects Beyond Basic Mulch
If you’re feeling a bit more hands-on, try these projects.
Building a “Slow Compost” Pile
Stump grindings are high in carbon (brown material). You can compost them, but they need a lot of nitrogen to break down efficiently. The best method is to create a separate, slow compost pile. Layer the grindings with high-nitrogen greens like grass clippings, kitchen scraps, or manure. Turn it occasionally. In 1-2 years, you’ll have a wonderful, earthy compost.
Creating a Natural Playground Surface
For a soft, forgiving surface under a swing set or play area, stump grindings are a great, low-cost option. They provide more cushioning than bare ground. Ensure the grindings are free of large, sharp splinters and maintain a deep layer for safety.
Erosion Control on Slopes
On a bare slope prone to washing away, a thick layer of stump grindings can help hold the soil in place. The interlocking chips absorb rainfall and reduce runoff, giving plants a chance to establish their roots. This is a simple and effective solution.
What to Avoid: Common Mistakes
Knowing what not to do is just as important.
- Don’t Use Them Fresh in Vegetable Beds: As they decompose, fresh grindings can temporarily tie up soil nitrogen, starving your plants. They’re best used around established plants or composted first.
- Don’t Pile Against Tree Trunks or Plant Stems: Always leave a few inches of space around the base of plants to prevent moisture buildup and rot. This is called “volcano mulching” and its harmful.
- Be Cautious with Certain Trees: Grindings from black walnut or tree-of-heaven may contain allelopathic chemicals that inhibit plant growth. It’s best to compost these thoroughly for a long time before use.
Step-by-Step: Making Leaf Mold with Grindings
This is a superb way to create a soil conditioner. Here’s how:
- Rake fallen leaves into a pile.
- Mix in about one part stump grindings to three parts leaves.
- Moisten the pile if it’s dry.
- Contain the mix in a simple wire bin or just leave it in a mound.
- Let it sit for 12-18 months, turning it once or twice if you can.
- The result is a crumbly, dark material that improves soil structure wonderfully.
This process works because the grindings add bulk and air pockets, helping the leaves break down faster without matting. It’s a fantastic reuse of two common yard “wastes.”
When to Let Them Decompose First
Sometimes, the best action is inaction. If you have the space, simply pile the grindings in an out-of-the-way corner and let nature take its course. In a year or two, the pile will have shrunk and the material will be darker, softer, and more suitable for direct use in gardens. Covering the pile with a tarp can speed up decomposition by retaining heat and moisture.
Remember, stump grindings are not a finished soil amendment. They are a bulking agent and a long-term organic material. Their value comes from improving structure over time, not providing immediate nutrients. By thinking of them as a resource, you save money on mulch and soil, reduce landfill waste, and improve your garden’s health. It’s a win all around.
FAQ: Your Stump Grinding Questions Answered
Can I use stump grindings as a soil?
No, they are not soil. They are a soil amendment. You should mix well-aged grindings into your soil to improve aeration and organic matter, but don’t plant directly into fresh piles.
How long do stump grindings take to decompose?
It depends on the tree type, chip size, and climate. Generally, it takes 1 to 3 years for them to break down significantly. Softwoods like pine decompose faster than hardwoods like oak.
Are stump grindings good for grass seed?
No, you should not mix fresh grindings into soil for a new lawn. The decomposition process will create air pockets and uneven settling, leading to a lumpy lawn. Use them elsewhere and use topsoil for grass.
What can I do with leftover stump grindings?
If you have extra, offer them to neighbors or on a community board. Many gardeners are happy to take free mulch. You can also contact local parks or community gardens—they often need material.
Do stump grindings attract termites?
While any wood material can potentially attract insects, stump grindings are not a significant risk, especially when spread out as a surface mulch. Termites prefer consistent, moist contact with soil and undisturbed wood. The chips dry quickly and are not ideal for them.