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How to Grow a St. Johns Wart Plant

By Joyce Starr ; Updated September 21, 2017

St. John’s Wort (Hypericum) is in the family of Hypericaceae and is a perennial herb. St. John’s Wort is a hardy, woody shrub that can obtain a height of 3 to 4 feet. Its striking bright yellow flowers stand out among the summer foliage, with a multitude of pistils shooting from their centers. Novice gardener’s will find St. John’s Wort a colorful addition to their gardens and quite easy to grow.

Select an area in your garden that receives full sunlight to partial sun. St. John’s Wort performs best if planted in an area that receives at least four hours of direct sunlight each day.

Consider its soil requirements before planting. St. John’s Wort grows best in a sandy soil amended with an organic material such as compost or peat. It prefers to grow in an area that drains well, as it will not tolerate soggy conditions.

Consider the particular species size when selecting an area. Varieties such as Golden St. John’s Wort can reach a height and width of 3 to 4feet. Other varieties such as Hypericum Moseriamum grow 1 to 2 feet tall. The planting site should accommodate its maximum size.

Plant St. John’s Wort seeds in early spring, when frost has left your region. Plant the seeds ¼ inch deep within the soil. Sprinkle soil on top of them. Do not cover the seeds with a heavy amount of soil, or they may not germinate.

Water the planting area, keeping it moist but not flooded. Keep the soil moist until the seeds have germinated. Once the plants have started to establish themselves, you can cut back watering to two times per week. St. John’s Wort is relatively drought tolerant once established, but keeping the area moist will provide the best growth.

Fertilize the St. John’s Wort once per week with a 20-20-20 water-soluble fertilizer. This will keep the plant at its optimum level of health and it will produce more blooms. An annual application of organic compost will also benefit the plant.

Prune only to remove any dead wood or to control the plant’s size.


Things You Will Need

  • Compost
  • Peat
  • Water
  • Water soluble fertilizer


  • Dry the flowers and leaves and store them in an area that is cool and dry.
  • Flowers bloom from early summer through early fall.
  • St. John's Wort is relatively pest free.

About the Author


For over 25 years, Joyce Starr has owned businesses dealing with landscape & design, lawn maintenance, specialty herbs and a garden center. She holds certificates in landscape design and xeriscaping. Starr shares her passion for nature in her writing, publishing articles on horticulture, outdoor recreation, travel as well as business.