Remove weeds and grass around the base of your arborvitae, using a weeder to loosen them. Use your hands to pull them out of the ground. Place the weeds and grass into a garbage bag to discard them.
Turn on your garden hose. Place the hose on a gentle stream setting. Lay the hose down and allow the water to saturate the area thoroughly. Allow the hose to run for 10 minutes. This adds moisture to the soil surrounding your arborvitae.
Spread mulch around your arborvitae. Start 6 inches from the stem. Layer 2 to 3 inches of mulch around the base of your arborvitae.
Use a bow rake to spread the mulch evenly. Avoid piling mulch around the base of your arborvitae.
Place a fresh batch of mulch around your arborvitae, at least once a year. This adds minerals to the soil and promotes growth.