Your calendar is already marked.
The easiest way to remember when to fertilize your lawn is to let the three summer holidays remind you.
Weed and feed applications should be done some time around each of the holidays: Memorial Day, Independence Day, and Labor Day. This schedule provides an early fertilization to get your lawn growing in the beginning of June. Then as your lawn is growing well and the temperatures are consistently warmer another fertilization will help stave off weeds and strengthen the roots. Finally the early September fertilization will keep you lawn green as long as possible and also keep it healthy as we move into the winter months.
The summer holiday rule of thumb will help your lawn stay green and growing throughout the summer.
If you are looking to enhance things a bit more, include an early April “pre-emergent” fertilization and an early November “winterizer” fertilization. This will assist in keeping your lawn weed free. Always remember, to never do an application during very dry or wet conditions. Applications work best if done in the early morning or at dusk. This allows the dew on the grass to assist in dissolving the chemical.