Lawns can deteriorate to the point where they cannot be nurtured back to an acceptable level of quality by using standard cultural practices such as fertilizing, proper watering, etc. Complete renovations of existing turf should be carried out if a lawn is composed of at least 50% weedy and undesirable grass species.
Renovation during late summer/early fall generally yields the best results. Minimal weed competition as well as cooler temperatures and ample rainfall usually follow late summer renovation, thus providing a favorable environment for new seedlings.
Late summer seeding must be accomplished early enough to allow the grass to become well established before the onset of cold weather in order to enhance winter survival.
Renovation may be attempted during spring if absolutely necessary. During late spring, however, extensive weed competition coupled with summer drought and heat stress can reduce the probability of success.