This was a fun craft! The best part was getting to reuse something I would normally just toss in the recycle bin. We used old Silk Almond Milk and Horizon Half and Half half gallon cartons (water tight, no leaking). First, I cut off the tops and washed out with soap and set aside to let dry.
Next, we primed them using Premium Gesso Canvas Primer. It absorbs well to accept oil and acrylic colors, pastels, charcoal, pencil, and crayon. You can use it on a wide variety of surfaces besides just canvas. This acrylic Gesso primer is non-toxic as well. I would highly recommend using a primer. If you don’t, your paint may not stick to the material. We used two thin coats of primer before painting.
After the paint was dry we took a trip to our local Armstrong Nursery and picked out some colorful flowers and wild, spiky grass. You could also fill the planters with potting soil and plant seeds (wheat grass or catnip) or herbs.