Summer lawn care requires raising the lawn mower for cool season grass, and lowering it for warm season lawns. Lawns will require longer and more frequent watering, best done in early morning to encourage a stronger root system. This is also the time to apply an all-purpose fertilizer. During the hot summer months, lawns may be susceptible to fungus disease. It’s advisable to take a sod sample to a local landscape expert for testing and treating the yard, if necessary.