Plant the smother crops in the fall and kill them off in the spring before the desired garden vegetables are planted. Do not use this method if small seeded vegetables such as lettuce are going to be grown because their germination will be reduced. Also, rotate where the smother crops and vegetables are being planted in the garden. If the same crops are grown in the same area every year, then the amount of weeds will increase. Mulches can be used to prevent weed germination and growth in gardens.
Organic mulches consist of plant matter and naturally decompose in the soil.
Those that are commonly used in gardens include manure, bark chips, ground corncob, sawdust, leaves, straw, etc. Do not use straw that contains weed seeds as mulch. If the straw does contain weed seeds, water the straw until the seeds germinate and then air-dry repeatedly until the seedlings are killed. When applying the mulch in the garden soil, spread the mulch evenly three to four inches deep around the base of the vegetable. To water and fertilize the vegetables, simply rake back the organic mulch and then return it after watering.