When to Plant Sea Holly

• Sea holly is grown from seeds and plant divisions. Because the seeds need a chilling period in order to sprout in the spring, they are planted in the fall in September or October. Plants or established seedlings can be planted in the fall or early spring as soon as the ground can be worked.
  
  

Planting Location

• Sea holly thrives in dry, warm locations. It requires well-drained soil to survive, so it must be planted where water does not stand after a rain. The long taproot helps it find moisture, so the soil must be sand or sandy loam to allow the taproot to penetrate the soil. A soil of hard clay will stunt the sea holly's growth or prevent the taproot's search for water. Other than needing a well-drained location, sea holly is tolerant of most other growing conditions. It can survive in full sun to part shade, which means it needs at least four hours of direct sun each day.
  
  

How to Plant

• Cover sea holly seeds very lightly with soil. Mark the location so you remember where they were planted. The germination time for sea holly seed may be 10 weeks or longer. You may not see new plants until very early spring.
  
  Be very careful when transplanting sea holly plants because damage to the taproot may kill the plant. If shopping for new plants, choose healthy, young, stocky plants rather than older, tall, stringy plants that may have a long taproot. The taproot of older plants may be curled at the bottom of the container.
  
  Plant sea holly at the same depth it was planted in the container. Add water around the plant after it is planted to settle the soil and remove any air pockets around the roots.
  
  

Sea Holly Care and Propagation

• Within its planting zone, sea holly is highly adaptable. Excess fertilizer creates soft, lush growth that is susceptible to insect damage and sunburn, so fertilize sparingly. Too much water can drown the plant, so water an established sea holly plant only when it shows drought stress.
  
  Sea holly can be propagated in the fall by gathering the dried seeds from the old flower heads or by division. To divide sea holly, look for new plantlets at the base of the plant, and carefully cut them away from the mother plant using a sharp garden tool, being careful not to damage the plantlet's developing root system.