You can take waste gum bootz and fill them with mud or soil and plant a sapling in it . You can also take matka and decorate it nicely and plat a sapling in it . One more idea if you are having baby paddle car of plastic which is big in size then join a wood or heavy duty cardboard down side and and fill with soil and plant sapling in it . These are the best idea
Take a water can & fill it with soil . then you can plant a saplings.. you can also cut water bottle in 2 pieces & in the 2nd part you have to fill  the soil & plant a sapling. you can also plant saplings in a waste bucket. these are some of the best ways to plant a tree