Summer Weed Control in Alfalfa When soil moisture is available after a cutting of alfalfa, the grasses and weeds will grow just like their name suggests: like weeds. How can these plants be held at bay? Thick alfalfa stands will be the first defense against foxtail, crabgrass, pigweed, etc. A good fertility plan to keep stands ...PLEASE LOG IN FOR PREMIUM CONTENT. Our website requires visitors to log in to view the best local news. Not yet a subscriber? Subscribe today!