How to Plant Forsythia in Containers

Prepare containers for the forsythia. Since the plants are such rapid growers, it is best to select large containers that provide the plants room to grow a large root system. Forsythia does not need any special soil to grow, so you can use any potting mix or even soil dug up from your yard to fill the containers. Adding compost or peat moss to the soil provides additional nutrients that help forsythia grow, however, and can be mixed into soil at a 1-to-1 ratio.

Take a cutting from another forsythia plant to begin a new plant. According to Easy Balcony Gardening, the forsythia cutting should be taken between late spring and early fall and be a roughly 3- to 6-inch piece of branch from a healthy forsythia shrub.

Plant forsythia cuttings just deeply enough in the soil mix that the cuttings can stand up on their own. Water the plant to moisten the soil and move the containers to a location where the forsythia plants get at least partial sunlight during the day. If you can put them in a location that receives full sunlight for six to eight hours a day, the plants will thrive.

Keep forsythia moist at all times, but never let the plants stand in water. To encourage the growth of the plants, use a fertilizer once each year. Any rose or all-purpose fertilizer will do. When applying fertilizer, always follow the directions provided on the packaging.

Prune the forsythia plant to boost its health and to keep it the appropriate size. When pruning, cut away any dead, diseased or infested wood and remove up to one-third of healthy wood to stimulate the growth of new wood. With a container-grown forsythia, you can also trim all stems back to half of their length to keep the plant's size in check.