Populations of weeds that do persist under frequent, low mowing can be minimized by raising mowing heights. To survive stressful periods, turfgrass weeds have developed dormancy mechanisms to allow the plant to resume a full growth rate when conditions return to normal. Through the production of seeds or vegetative organs such as stolons, rhizomes, tubers, corms, or bulbs, a weed can persist at a minimal metabolic rate, preserving the necessary tissue and food reserves for re-growth after the dormant period. Annual weeds are prolific seed producers , ensuring future generations of the species. Perennial weeds, while producing some seed, may rely more on storage organs to persist from season to season.
Several conditions can prevent the immediate germination of weed seeds.
These include a hard seed coat that mechanically prevents the imbibition of water or expansion of the seed within the seed coat. Some species produce inhibitors that must be leached from the seed coat before germination can begin. Other turfgrass weed species require short periods of light exposure to initiate the germination process. Some species shed seed from the plant before it is fully mature , requiring an after-ripening period before germination can occur. Seeds of certain species have been shown to survive in soil for long periods of time.