How To Hollow Out A Tree Stump

If you have an old tree stump in your garden, you might be wondering how to hollow out a tree stump. This simple project can turn an eyesore into a charming planter, a natural bird bath, or even a unique garden seat. It’s a practical way to recycle the wood and add character to your outdoor space without the cost and effort of full removal.

This guide will walk you through several simple and effective methods. We’ll cover everything from basic hand tools to using natural decay. You’ll learn which approach fits your timeline, budget, and physical effort.

Before you start, it’s crucial to pick the right stump. A soft, rotting stump is much easier to work with than a freshly cut, hard one. If the wood is already spongy and breaks apart easily, your job will be simpler. For hard stumps, you may need more powerful tools or patience for natural methods.

Always check what type of tree it was. Some woods, like cedar or black locust, are incredibly dense and rot-resistant. Others, like pine or poplar, are softer and more cooperative. Knowing this helps you plan your attack.

Essential Safety Gear and Prep Work

Safety is your first priority. This work creates flying debris and dust. Never skip your protective equipment.

Eye Protection: Safety goggles are non-negotiable to shield your eyes from wood chips.
Hearing Protection: Earplugs or muffs are essential when using loud power tools.
Gloves: Wear sturdy work gloves to protect your hands from splinters and vibrations.
Dust Mask or Respirator: Wood dust, especially from treated or old wood, is harmful to breathe.
Sturdy Clothing: Wear long sleeves and pants to protect your skin.

Next, prepare the stump itself. Clear away any rocks, dirt, or vegetation from around the base. If the stump is tall, consider cutting it down to a more manageable height with a chainsaw first, leaving maybe 2 to 3 feet. This gives you a better working area and uses less materials if your making a planter.

Method 1: Using Hand Tools (The Traditional Approach)

This is the most accessible method, requiring tools you might already own. It’s quiet, low-cost, but physically demanding. It’s best for smaller or softer stumps.

Tools You’ll Need: A heavy-duty wood chisel, a mallet or hammer, a drill with a large spade bit (1 inch or wider), and a hand saw or reciprocating saw.

Drill Pilot Holes: Start by drilling many closely spaced holes inside the area you want to hollow. Drill as deep as you can. This weakens the wood core and makes chopping easier.
Chisel Out the Wood: Use your chisel and mallet to break apart the wood between the holes. Work from the center outward. Angle the chisel to carve away chunks.
Clear and Shape: Regularly clear out the loose wood chips. Use your saw to cut through any stubborn fibers or to even out the edges. Take your time and let the tools do the work.
Create Drainage: If making a planter, drill a few holes down through the bottom of the hollowed section into the roots below. This prevents water from pooling and causing rot too quickly.

Method 2: Using Power Tools (The Faster Way)

For harder wood or larger stumps, power tools save significant time and labor. The key tool here is a chainsaw, but it must be used with extreme caution for this detailed work.

Tools You’ll Need: A chainsaw (preferably a smaller, more manageable one), a drill, a chisel for cleanup, and a reciprocating saw can be helpful.

Make Cross-Cuts: With your chainsaw, make a series of parallel cuts across the grain inside your marked area. Don’t cut all the way to the edges—leave a border of several inches for the walls.
Make Perpendicular Cuts: Now make another series of cuts perpendicular to the first ones, creating a checkerboard pattern of deep grooves.
Break Out the Cubes: Use your chisel and mallet to pry out the wooden cubes created by the saw cuts. The chainsaw has done the heavy slicing, so this part is easier.
Clean and Smooth: Use the tip of the chainsaw (carefully!) or a reciprocating saw to smooth the bottom and walls. Always be mindful of kickback when using the chainsaw tip.

A word of warning: Using a chainsaw for hollowing is an advanced technique. If you’re not experienced, consider using a rotary tool (like a power carver) with a heavy-duty wood-cutting bit instead. It’s slower but much safer for detailed hollowing work.

Method 3: The Natural Rot Method (The Patient Gardener’s Trick)

If you’re not in a hurry, let nature do the heavy lifting. This method uses moisture and nitrogen to accelerate the natural decay process, softening the stump from the inside out.

What You’ll Need: A high-nitrogen fertilizer (like pure nitrogen lawn food), a plastic tarp, and a source of moisture.

Drill Deep Holes: Drill many 1-inch-wide holes across the top of the stump. Drill down as deep as you can, and also drill holes into the sides of the stump at an angle.
Add Nitrogen: Pour the high-nitrogen fertilizer into all the holes. This feeds the microbes and fungi that cause decomposition.
Add Water: Soak the stump thoroughly with water. The wood needs to be damp to rot.
Cover It Up: Cover the stump with a black plastic tarp. This retains moisture and heat, creating a perfect “compost” environment. Weigh down the edges with rocks.
Wait and Reapply: Check every few weeks, adding more water and a bit more fertilizer if things dry out. Over several months, the center will become soft and spongy.
Hollow the Soft Wood: Once the center is thoroughly rotted, you can often scoop it out with a sturdy trowel or garden shovel. You may still need a chisel for harder parts, but the work will be dramatically easier.

Finishing and Sealing Your Hollowed Stump

Once hollowed, you need to protect your creation. If left untreated, the wood will continue to decay and may only last a few seasons.

For Planters: Line the hollow with a heavy-duty plastic liner (with drainage holes poked through) before adding soil. This prevents soil contact from speeding rot. You can also apply a wood sealant meant for outdoor use to the inside and outside.
For Decorative Features: Applying a wood preservative or a penetrating epoxy stabilizer is key. This soaks into the wood, hardening it and protecting it from water and insects. For a natural look, use a clear, waterproof sealant.
Let it Breathe: Ensure whatever sealant you use allows the wood to release moisture vapor, or it could trap water and cause decay from within.

Creative Ideas for Your Hollowed Stump

Now for the fun part—what to do with your new garden feature!

A Tiered Planter: Plant trailing flowers like petunias in the center, and surround the base with colorful annuals.
Fairy Garden: Create a whimsical miniature scene inside with small plants, pebbles, and tiny decorations.
Bird Bath: Place a shallow, snug-fitting ceramic or glass bowl into the hollow and keep it filled with fresh water.
Garden Seat: For a large, flat stump, hollowing can reduce weight. Add a weatherproof cushion on top for a rustic sitting spot.
Night Light: Place a solar-powered or battery-operated lantern inside for a magical evening glow.

Common Problems and Solutions

You might encounter a few hiccups. Here’s how to handle them.

Encountering Rocks or Nails: Always be alert. If your drill bit or chainsaw hits metal, stop immediately. You may need to abandon that spot or carefully work around it with hand tools.

The Walls Are Too Thin: If you get overzealous and the walls become weak, you can reinforce them from the inside. A concrete patch mix or expanding foam (painted over) can add structural integrity. Just ensure it’s sealed from moisture afterwards.

Ants or Bugs Move In: Hollow stumps can attract insects. A borate wood treatment applied during sealing can deter pests. For an existing problem, use an appropriate insecticide labeled for outdoor use around the exterior base.

FAQ Section

What is the easiest way to hollow a tree stump?
For most DIYers, combining a drill with hand chisels is the easiest and safest method. It requires minimal specialized tools and gives you good control.

How long does it take to hollow out a stump by hand?
It depends entirely on the stump’s size and hardness. A soft, small stump might take an afternoon. A large, hard oak stump could take several weekends of work.

Can you use fire to hollow out a tree stump?
We do not recommend using fire. It’s extremely dangerous, difficult to control, can damage surrounding trees and property, and often leaves a thick layer of useless charcoal instead of a nicely hollowed space.

What is the best tool for hollowing out a stump?
For speed, a chainsaw is powerful but requires skill. For control and safety, a powerful drill with auger bits followed by a reciprocating saw and chisels is a very effective combination.

How do you make a tree stump planter last longer?
The single most important step is sealing the wood. Use a high-quality wood preservative or epoxy stabilizer, and always use a plastic liner to separate the soil from the wood interior. This can add years to its life.

Hollowing out a tree stump is a rewarding project that blends gardening with a bit of woodworking. By choosing the right method for your situation and taking the necessary safety precautions, you can successfully convert a leftover stump into a beautiful focal point for your yard. Remember, the key is patience—whether you’re wielding a mallet or waiting for nature to assist. With a finished hollow stump, you’ll have a unique piece of garden art that tells a story.