Interior Structure

I went to my local Home Depot and got three 4' cardboard concrete form tubes -- one 8", one about 9" and one about 10" in diameter. (They're sold in 6", 8", and 10" sizes but in reality none of them seem to be exact, so it was easy to find three that telescoped nicely inside each other.)

I used a jig saw to cut out about 1/3 of each tube to create a flat side that would go against the wall. This allowed me to bend the cardboard so it would transition smoothly between pieces. I lined the three pieces up, drilled holes, and secured the sections together with zip ties.

I also added a couple shorter cut-off branches using the discarded parts of the cardboard tube to give the tree some interest.

Larger Branches

I made the largest branches out of cardboard mailing tubes. To shape them, I cut a wedge of cardboard out to allow for a slight bend, then used duct tape to get the branch to hold its shape. This creates a very solid and supportive branch with some good stiffness to it.

Smaller Branches

I used foam pipe insulation in varying sizes to create the smaller branches. I cut a piece of 18ga wire a few inches longer than the foam, then slid the wire inside the foam insulation and gave it a few random bends in 3 dimensions to mimic the wiggly oak branches on my trees outside. 

Cover with Expanding Foam

Lay down some plastic garbage bags or drop cloth on your surface and floor first! Expanding foam is very messy and sticks to almost everything. I ruined at least three tops and four pairs of yoga pants during this phase.

I used the least expensive "Gaps & Cracks" type of foam, which worked great. A couple tips for using this stuff:

  • Wear gloves and protective clothing! This stuff gets everywhere and Does Not Come Off.
  • It comes out sticky and soft, and sets up in around 45 minutes. Misting it with water shortens the surface setting time to around 20 minutes, so have a spray bottle handy to speed up your process.
  • The foam will slowly expand to about 2x its size after you spray it, so lay your lines close together so they "grow" towards each other.
  • It's best to use up the whole can once you've opened it. The little sealer valve doesn't quite live up to it's job. If you want to try and save the rest for later, cover the tip of the straw with duct tape so no air can flow in/out.

Spray the foam lengthwise in long strokes along the branches. It doesn't look much like bark yet, but don't worry. I found it was easiest to do this in two steps, covering the top of the tube and letting the foam set up, then flipping it over and doing the other side. This doesn't have to be perfect -- in fact, the messier it is, the more realistic it looks in the end. Nature is messy.

I used the same method for the trunk. I also added two branch collar sections, to imply that branches had been flush cut earlier in the life of the tree. This is a fancy way of saying I made a couple big circles on the side of the trunk with the foam.

I did not add any foam for the Ent face just yet -- I found it was easier to do that after the next step of carving down the foam.


Let the foam fully set up overnight so it's firm when you press on it and not squishy.

Please wear safety glasses while doing any cutting or other work to protect your eyes! Wear a mask when working around anything creating dust.

Wear safety glasses and a mask during this portion. You don't want to breathe this stuff and it gets crumbly and messy!

Take a rough-toothed saw -- I used a keyhole saw, but a wood saw or even a sharp bread knife would work as well -- and saw along the length of the branches and trunk, cutting off about half the foam. Change the angle of your saw frequently. You don't need to be too exact here either, but cut off all the rounded "cartoony" bits of the foam. Underneath the surface you'll find a delightful bark-like texture.

Ent Face

Once the trunk is fully carved, it's time to decide exactly where you'd like the Ent face. Place your Monster M4sk on the tree until the placement feels right and the tree tells you YES. Mark where the eyes go, then use your keyhole saw to cut through the foam and cardboard to make holes that are just right for the eyes.

To compensate for the curvature of the trunk, I used a dremel to carve out notches on the inside so that the eyes can sit closer to the trunk.

Add more expanding foam around your eye holes and carve your face with the keyhole saw. You can always add more foam if you take off too much.

Here is my Pinterest board for inspiration! I started out envisioning mustaches and eyebrows and lots of detail, but ended with something rough and wild and more suggestive than representative. I am not a sculptor, but I'm happy with my results anyway.


I used 3 colors of latex house paint to color and seal the foam: 

  • Onyx Black
  • Chocolate Brown
  • Light Grey

Experiment on a small branch first to be sure you've got the colors right. Oak trees are predominantly grey with a brownish/blackish undercoat. Take a real tree branch to the paint store when you're choosing your colors for the best and most realistic match.


Dip your paint brush in water, then in the black paint. Let it be a little drippy. Paint the foam, getting all the bristles of your brush into the crevices and cracks. Cover as much as you can with one dip.

Next, dip in water again and then in brown. Paint the next section in brown, overlapping with the black. 

Continue alternating brown and black, getting the paint into all the crevices.

Top Coat

Let the base coat dry about halfway, so it's no longer drippy. Take a dry brush and dip it in your grey paint. Run the brush lightly across the foam, just painting the high sections, keeping the cracks and crevices dark. 

This guide was first published on Feb 12, 2020. It was last updated on Mar 08, 2024.

This page (Build the Tree) was last updated on Mar 08, 2024.

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