What you'll need:
- lamp shade
- foam gym floor mat square
- adult suspenders
- bag of moss
- brown hoodie, a couple sizes too big
- dark and regular brown felt squares
- one square green felt
- hot glue gun
- black sharpie
The first four items I found at a thrift store, the rest I already had lying around the house.
Cut the metal parts off of the lamp shade and trim the floor mat to fit a few inches deep into the upside down lamp shade. Make sure it's wedged in really good so it doesn't pop off when your kid is walking around.
Cut a hole out for your child to be able to fit inside. You can make a small one at when you're first working on it, but eventually you'll have to cut it fit around your child's belly with the hoodie (and layers if it's cold outside) on.
I sewed the suspenders to the *bottom* of the upside down lamp shade. The reason why we're using adult size suspenders is because we are going to stretch them up through the floor mat hole, to wear directly under the hoodie. I bought the hoodie a couple sizes too big because I wanted him to be able to wear warm layers under his costume and because the bottom half of the hoodie needs to be under the gym floor mat (I've never seen a tree with a belly button, have you?).
No comes the labor intensive part: cutting out and hot gluing the bark. I did an under layer of thin dark brown (with a few regular brown mixed in) felt bark strips, with a layer of bigger approximately 6"x3" pieces of bark on top. I used the sharpie to outline each uniquely shaped piece and to add a wood grain look to them. For the hood instead of lining it with bark I made a crown of twigs by folding a square in half to give it depth, cutting the twig shapes on the front and side and gluing it to a felt headband to wear as a removable crown.
For trick or treating my son had on his thermal sweater and olive (tree root?) colored pants. He stepped into the lampshade and we pulled the suspenders over his shoulders then put on the hoodie. Once this was one we wedged the floor mat square into place and placed the moss on top.
Complete costume by dancing to Jackson 5's "Want You Back" and saying "I am Groot!" all night instead of Trick or Treat.