Companion crops are commonly used to protect the young seedlings and provide a snow trap for the first winter. Cereal crops and canola have been successfully used, although if moisture is inadequate during the growing season the timothy may establish poorly. Flax makes a good nurse crop, as it offers adequate protection while allowing a considerable amount of sunlight to reach the seedlings. Weed Control Weeds can adversely affect the chances of a successful establishment of timothy. The seed field should be free of perennial weeds, especially couchgrass, Canada thistle , sowthistle , dandelions and red or alsike clover.
Annual weeds can be a problem as well.
There are no controls for green foxtail or barnyard grass in seedling timothy. As weed control options are limited, it is best to avoid such problems and seed timothy into clean fields. During the cropping years, certain weeds will cause seed cleaning problems. Just one wild mustard seed in the final sample will make the seed ineligible for any of the pedigreed grades. Other problems are caused by stinkweed , green foxtail , rough cinquefoil and the clovers.