Good idea for multiple reasons: equisetum (horsetail, snake grass, puzzlegrass) (grow zone grows so quickly and make even the newest newbie of a gardener feel accomplished and happy. equisetum can get out invasive and a container will control it.
To make a river stone mat first you have to gather or purchase river stones. After that take a plastic mat and arrange all the stones on it. Then stick all the stones one by one to the plastic mat by using silicone sealer. Let the sealer dry completely.
Make cute and easy up-cycled DIY mood lighting from old cans! Great craft inspiration for summer parties and BBQs! After poking holes in the cans, paint them to match patio furniture! Mozzie repelling candles make this idea even better: )