If you’re interested in growing your own medicinal plants, St. John’s wort is a must-have for your garden.
Not only is this herbal ally exceptionally easy to grow, but it also has multiple uses. Read on to learn how to grow it, propagate it, and how to use it medicinally.
What is St. John’s Wort?

St. John’s wort (Hypericum spp.) is a herbaceous perennial flowering plant in the Hypericaceae family. This is also known as the St. John’s wort family and encompasses more than 700 species.
It got its common name from its association with St. John the Baptist.
Interestingly, the best time to harvest this plant is around that saint’s official day: June 24th (or thereabouts, depending on your location). In pre-Christian Celtic culture, it was associated with the sun and used in fertility and divination rituals.
In North America, it’s also colloquially known as “Klamath weed.” This is because it became an incredibly invasive species in California’s Klamath River region early last century. By the mid-1940s, it had taken over and two million acres spread across 30 northern California counties.
Although there are several hundred different medicinal species in this family, Hypericum perforatum is the most common. It’s also the one most often used in medicinal preparations.
Planting St. John’s Wort
This sweet little plant is remarkably hardy and grows in some pretty rough conditions. It prefers sandy soil that’s a bit acidic but can really grow just about anywhere.
I have it all over my property, from the sandy patches on the hillside to loamy areas beneath pine and spruce trees.
One of the easiest ways to propagate St. John’s wort is by planting seeds. Additionally, you can grow new plants from cuttings or divide roots from mature plants and transplant them. Since this is a perennial herb, it will keep coming back year after year once established.
To sow the seeds, rake the earth, scatter the seeds around, and cover with a light sprinkling of soil. Water well, but don’t soak them. Then be patient, because it takes at least three months for these babies to germinate. In fact, you may only see flowers the following year.
Alternatively, if you want to speed the growing process, start your seeds inside the house three months before you plan on transplanting them outdoors. They can be difficult to germinate indoors, so try soaking them for 12-24 hours before planting.
This plant doesn’t like to be over-watered. It prefers drier conditions and can wilt if you soak it too often. Keep the soil around young plants moist, but let that dry out a bit once they’ve matured.
Although St. John’s wort needs a fair bit of light to thrive, it does best in partial sun. This is because direct sunshine during the hottest part of the day can actually burn it.
In fact, this trait may be associated with its tendency to cause photosensitivity in people who take it long-term.
General Care and Feeding

This plant pretty much thrives on neglect. It doesn’t need to be fertilized unless your soil is incredibly depleted.
If you’re planting new seeds or transplanting seedlings, then work some compost into the soil before planting. Otherwise, offer your St. John’s wort plants a deep drink of good compost tea a few times during the growing season.
After you’ve harvested the plant’s aerial parts for medicinal preparations, prune the branches back a bit. This can help encourage a second flowering later in the summer.
Potential Problems and Solutions to Growing St. John’s Wort
This plant is ideal for attracting pollinators and only has one official pest: Chrysolina quadrigemima, also known as the “Klamathweed beetle.”
If you have livestock or outdoor herbivore pets, make sure that you don’t grow St. John’s wort anywhere near their grazing areas. It’s toxic to most grazing animals, especially to horses, rabbits, sheep, and goats. It can also poison dogs and cats, though they tend to avoid it.
Not only will this damage them internally, but it can also make them extremely sensitive to sunlight. Herbivorous animals that graze on St. John’s wort regularly can receive severe sunburns in addition to being poisoned by the plant.
Additionally, remember that this perennial herb is considered invasive for a reason. If you plant it right into your soil and allow it to establish itself, it can be tough to eradicate.
Are you hesitant about introducing non-native species to your region? Then grow your St. John’s wort in pots instead.
Harvesting and Storage
There are a couple of different ways to harvest this herb to use later. One is to snip the flowering heads off as soon as they appear. Then, place these in a hanging mesh drying rack or basket for a few weeks until they dry out completely.

Alternatively, harvest full branches and tie them together. Then stick their flowering ends into a brown paper bag. Tie this bag closed tightly around the stems, and hang it upside-down in a warm, dry room.
This allows the plant to dry out evenly, and the flower petals will drop into the bag once dried. That way, you don’t lose any precious medicinal components!
Once it’s all dried, transfer everything into a glass jar. Label it well with the harvesting date and species. Then store in a warm, dry location away from direct sunlight.
Medicinal Uses
This herb has been taken as a tea or tincture to combat depression for thousands of years. When used topically, it’s surprisingly good for speeding wound healing, alleviating pain from burns and scrapes, and rejuvenating the skin.
Studies show that St. John’s wort tea is remarkably effective at treating mild to moderate depression.
We’ll touch upon a full spread of medicinal preparations for this herb in a future article, including how to prepare and use tinctures and infusions made from it. For now, let’s focus on an easy infused oil recipe.
I received second-degree burns on my inner arms a few years ago, and St. John’s wort oil helped to speed healing exponentially.
It also alleviated pain during the healing process and prevented what could have been severe scarring. It also has high antibacterial properties, which helps to stave off potential infection in cuts and other wounds, as studies show.
St. John’s Wort Oil Recipe
This is one of the most basic, easiest herbal remedy recipes out there. You just need two ingredients and a bit of patience. Once it’s made, you’ll be able to use it for all manner of topical preparations.
Make sure to use fresh flowers rather than dried in order to get the full effect. I recommend letting them wilt on the counter or table for a couple of hours before using them, however. This allows any small insects that may be inside to escape before you immerse the blooms in oil.
Directions:
Wash and sterilize a glass jar, along with its lid.
Then, fill it 3/4 of the way full with fresh St. John’s wort flowers and buds. It’s okay if they’re not opened yet, or if the flowers are starting to wilt a little.
Next, fill the jar with the highest-quality extra-virgin olive oil you can find. You don’t need to fill it right up to the lid, but you can leave about 1/2 an inch of space up there. The key is to make sure the plant matter is completely covered, plus extra.
Close the lid, and place this oil in a sunny spot inside your home, like a windowsill. It needs to receive direct sunlight for several hours a day.
Let this sit in the sunshine like this for 3-4 weeks, and give it a bit of a twirl every couple of days. Just agitate the soil slightly—don’t shake it.
This oil is ready once it has turned into a gorgeous deep red hue. At that point, strain it into some clean, sterilized, amber or cobalt blue glass jars. Cap these and keep them in a dark cupboard until needed.
Daub this oil directly onto cuts, scrapes, wounds, rashes, and any other skin conditions you can think of. Alternatively, use this oil in topical, healing salves. For example, it combines well with comfrey, plantain, calendula, and arnica to alleviate pain and speed healing.