علف هرز
علف هرز     Nimblewill     Nimblewill (Muhlenbergia shreberi) grows as a native perennial grass in moist places in the eastern half of North America, but its green season is much too short to make it a good grass for lawns. This grass grows well through summer -- especially in partial shade -- and then becomes brown and fragile in early fall. To replace patches of nimblewill with turf grass, use a garden rake or hand cultivator to pull patches in September. Quickly fill open spaces with seed or sod that matches the rest of your lawn. In spring, mow infested areas very low and replace them with better quality grasses.   Weed Control Techniques   Pulling. Most young weeds can be pulled from the soil. They will slide out most easily if you pull them when the soil is wet. Getting the root up is crucial, so think of the main stem as the root's handle, and grasp it as close to the soil line as you can. If you find that the weeds are breaking off at the crown as you pull, slip a kitchen fork, dandelion weeder, or similar tool under the weed, and pry and twist as you pull it up. Weeds that have taproots, such as dandelion and plantain, usually must be pried out. A flexible pair of waterproof gloves will keep your hands comfortable as you weed, and it's good to have a nice sitting pad, too. Let pulled weeds bake in the sun for a day or so before composting them. If pulled weeds are holding mature seeds, compost them separately in a hot, moist pile before using this compost in the garden.           منبع: مرکز مقالات کشاورزی AKE( بزرگترین وبلاگ کشاورزی ایران )