How to Grow St John’s Wort

How to grow St John's Wort - Hypericum perforatumAs we’ve recently begun to stock several ‘St John’s Wort’ species, we thought it would be a good idea to write up this guide covering the basics of how to grow St John’s Wort.

Native to parts of Asia and Europe, the flowering herbaceous perennial Hypericum perforatum is the “true” ‘St John’s Wort’, although the name is also often used to describe other related species. These include Hypericum hirsutum (‘Hairy St John’s Wort’) and Hypericum tetrapterum (‘Square-stalked St John’s Wort’). We’re currently able to offer healthy fresh seed of these three ‘St John’s Wort’ species, all of which should grow well under the method outlined here.

So, how to grow St John’s Wort? Well, most of the common Hypericum species are quite easy to grow from seed – whether you’re an experienced gardener or a total novice – provided that you are located in USDA Hardiness Zones 4-10 and keep the soil moist but not soaked. Read on to discover just how easy it is to start your own patch of this fascinating flower!

How to Grow St John’s Wort – Materials

  • Container or flowerbed
  • Disinfectant
  • Hypericum perforatum seeds (or related species)
  • Pruning shears
  • Water (tap water is fine)
  • Fertiliser (optional)
  • Garden trowel (optional)

How to Grow St John’s Wort – Method

  1. Prepare a container (or bed) of mildly acidic (pH 5.5 to pH 7) or neutral, moist yet well-drained soil (sand, clay, loam, rocky and sand are all fine) in full sun to partial shade.
  2. Sow seeds in autumn or spring (or plant seedlings or root cuttings in the spring).
  3. Cover them with a fine layer of soil and then lightly water. The soil must be kept moist but not sodden from now on.
  4. Once the perforatum seedlings are approximately five centimetres tall, thin them out into larger containers (or the ground). Space them at least fifty centimetres apart.
  5. From now on, water regularly to keep the soil moist but not waterlogged. Fertiliser may be applied sparingly to improve soil condition.
  6. Pruning will likely be required annually, which should be carried out in the early spring. To do this, disinfect the pruning shears and then carefully remove any crossing, dead or damaged stems. Note that trimming ‘St John’s Wort’ species in this way will usually prevent the plants from producing flowers that year.

Now you know how to grow St John’s Wort, browse the varieties we stock