I often use grass clippings as a mulch. They smother weeds and when they decay, they provide nutrients to the soil. You can also buy a small garden shredder for a couple of hundred dollars. This can be used to shred dried branches from trees and shrubs, up to 1 1/2 inches in diameter. This shredded material can be used as a mulch to cover flower beds, around the base of trees and as a natural covering for pathways through the garden. It will suppress weeds and since it dries out rapidly, it will inhibit airborne weed seeds which fall on it from germinating.