Make the trunk of the tree out of several pretzel sticks "glued" together with royal icing in the shape of a trunk or use 1 large pretzel stick. Cut the pretzels to size. Match the trunk proportionate to the house's height.
Follow the directions to make crispy rice treats. Double the amount of marshmallows in your recipe. This will make the tops of the trees harder.
Add green food coloring to the crispy rice treat pan. Use a small amount of brown food coloring if you want darker green leaves. Mix in the food coloring while the "leaves" are still hot.
Mold the tree tops into a ball. Wear the heat resistant gloves since you have to work with crispies mixture. Insert the trunk into the tree while it is still warm and pliable. Set aside.
Add decorative "apples" to the gingerbread house's trees. Use Red Hots or red sprinkles to get the best effect. Your trees are ready for the drive.