pre-emergence

Annual weeds establish from seed and complete their lifecycle in one year. Summer or warm-season annual weeds (like crabgrass) establish in spring, grow actively in summer, and die out in fall. Winter or cool-season annual weeds (like annual bluegrass) establish in fall, grow from fall to spring, and complete their lifecycle in warm temperatures in late spring. 

Often one of our biggest problems in the spring is fertilizing turf too early. Early application of fertilizer can lead to early green up. Though this may please the client, turf that greens up early can be more susceptible to damage by late cold weather. Early fertilization may predispose the turf to disease problems. Also, nitrogen applied too early may not be taken up by plant roots which are still dormant. This nitrogen can be lost by leaching and runoff.