Mulching each seedling with a 3 to 4 inch deep mat of old straw, hay, corn cobs, or wood chips approximately 12 to 18 inches around the seedling will reduce competition, conserve soil moisture, and reduce the soil temperature. When applying the mulch, remember to leave a small gap (approximately 1 inch) between the mulch and the stem of the seedling. Placing the mulch directly against the stem can create rot, harbor insects and diseases, and create other problems due to the increased moisture held by the mulch. The gap allows the stem to remain dry but still allows the mulch to create the desirable effects wanted.
Weed barrier fabric, available in 4x4 feet mats from the Conservation Tree Planting Program provides long lasting weed control and water conservation for conservation plantings. If larger rolls are desired, please consult a commercial dealer.
Do not use mulch over the top of weed barrier fabric. It is important to try and keep the material free from dirt and debris on top of the fabric for two reasons. The first is again due to the fabrics requirement of sunlight to break it down. The second is that if mulch, dirt, or tall grass is allowed to accumulate on top of the fabric, weed seed can germinate and send roots though the material. Weeds cannot grow from the bottom up through the fabric, but they can grow through the fabric from the top-down.