If anyone suggested putting in a garden in a baseball field, people would think you were nuts. We just had a similar situation where 1700 plants were put in a playground last year and a year later they are almost all dead and gone.
Kids running around in a limited area, playing soccer, tag, etc. are going to run right through the gardens and trample all the plants. That’s what happened in this one school garden. Do the math on buying 1700 plants and the effort involved in planting and you realize how much was wasted on that one garden.
One solution in a limited playground area is to put out a few large pots which are out of the way and can stand up to soccer balls. Large pots do need more frequent watering than plants in the soil.
Butterfly Gardening 