Planting trees in your park can add a lot of value to the area. Not only will trees provide much-desired shade, they'll improve the air quality of your local park, too.
Start by researching the types of trees you should plant. Make your choices according to the climate of your city so the trees will have the best chance of survival. When it's time to plant them, do it in areas that could use an aesthetic boost! Ideal spots are by water features (lakes and ponds) or around the playground and park benches. Or, pick a place where families like to picnic, and plant trees there to provide some privacy and shelter from the sun.