The popularity of black-eyed Susan flowers has increased due to the ease of growing these colorful perennials. The black-eyed Susan comes back every year, producing more blooms each time. This flower does reseed itself, but propagation by division is the easiest way to produce more plants. The bright color adds beauty when tucked around other plants in flowerbeds, but black-eyed Susans create a breathtaking sight when mass planted on their own.
Plant black-eyed Susans in a sunny location. These perennials love the full sun and will bloom prolifically throughout the growing season. The seeds will blow into nearby flowerbeds, so you may end up with more plants as the year progresses.
Water regularly during the growing season, making sure to let the soil dry between waterings. Black-eyed Susan is drought tolerant but does better with a thorough soaking at least once every week or two.
Divide larger plant clusters by digging them up and cutting through the root ball with a sharp knife. Start digging about 8 inches from the mother plant, and be sure to dig deep enough to get all the root hairs. Remove the root ball from the hole and simply cut straight through the middle of the black-eyed Susan cluster from top to bottom. Each section can be further divided if they are still good size. Generally, a nice size for replanting is just a little smaller than a soccer ball.
Remove spent blooms by cutting them off the plant with garden pruners or shears. This is called deadheading, which lets the black-eyed Susan concentrate on producing more flowers. Dry the dead blooms and save them in a container to plant in the spring.
Mulch the black-eyed Susan in late fall for protection during the cold winter months. Even though the plant is a perennial, certain areas reach very low temperatures that may damage the root system of the black-eyed Susan. Covering with mulch protects the plant for next year. In the spring, remove the mulch so young shoots can grow uninhibited.