Planting

• According to the National Gardening Association, rudbeckias grow best when planted in masses in a border or wildflower meadow. Look for a site that has full sun to light shade with well-drained soil. Plant the flowers in the spring. Prepare the garden bed by loosening the soil. Mix in 2 to 4 inches of compost. Dig a hole and then place the plant into the soil. Place the top of the root ball level with the soil surface. Fill in the hole with the rest of the soil and gently firm the soil. When planting additional rudbeckias nearby, space the plants approximately 2 to 3 feet apart form one another. The plants will eventually grow to about 2 to 6 feet tall, depending on the variety, and will start to bloom in the summer and fall.
  
  

Watering & Fertilizing

• Water the plant in the summer if there has been less than 1 inch of rainfall during the year. Also, apply a thin layer of compost and a 2-inch layer of mulch every spring. This will help the plant retain moisture as well as control weeds. Dayton Nurseries, a plant nursery in Norton, Ohio, recommends fertilizing rudbeckias every four months with a slow-release fertilizer, such as Osmocote, or fertilizing every couple weeks with Plant-tone or Miracle-Gro.
  
  

Pruning

• In spring, remove any dead foliage to help keep the plant healthy. After the first frost in late fall, cut the stems of the flower back to 1 or 2 inches above the soil line to protect the plant during the winter season.
  
  

Plant Division

• After growing for several years, perennial flowers can sometimes die back and start to produce fewer flowers. Therefore, it is best to divide rudbeckias every three to four years as new growth begins in the spring, according to the National Gardening Association. Plant division is a good way to keep your flowers healthy, and also helps control the size of your plant.