Gardening Trees, Shrubs & Vines Shrubs How to Plant and Grow St. John's Wort St. John’s wort is a pretty shrub with sunny, yellow blooms and year-round interest—but be prepared to manage its growth. By Viveka Neveln Viveka Neveln Viveka Neveln is the Garden Editor at BHG and a degreed horticulturist with broad gardening expertise earned over 3+ decades of practice and study. She has more than 20 years of experience writing and editing for both print and digital media. Learn about BHG's Editorial Process Updated on October 2, 2023 In This Article View All In This Article Where to Plant Planting Tips Care Pests and Problems Propagation Types Companion Plants FAQ Trending Videos Close this video player St. John's wort is a landscape workhorse that is a champion at providing food and shelter to wildlife—especially pollinators. The North American native offers bright yellow flowers in late June followed by reddish-brown fall berries and—when conditions are favorable—year-round green foliage. The shrub is easy to grow and a cinch to incorporate into almost any landscape. Since it is seldom browsed by deer and rabbits, St. John’s wort is also a great plant for landscapes plagued by these munching pests. St. John’s wort typically grows to about 3 feet tall and 2 feet wide and spreads rapidly via rhizomatous underground stems and shoots. For this reason, the plant is often found growing wild along roadsides, in grasslands, and in open woodland areas. In fact, its creeping growth habit has led to a few common names including goatweed, rosin weed, Klamath weed, Tipton weed, and devil’sscourge. It should also be noted that St. John’s wort is considered toxic to humans, dogs, cats, and horses. Use caution when planting the shrub in areas where pets and children play and wear gloves when handling or pruning the plant. St. John's Wort Overview Genus Name Hypericum spp. Common Name St. John's Wort Additional Common Names Goatweed, Klamath Weed, Tipton Weed, Devil's Scourge, Rosin Weed Plant Type Shrub Light Part Sun, Sun Height 1 to 3 feet Width 1 to 2 feet Flower Color Yellow Foliage Color Blue/Green Season Features Summer Bloom Special Features Attracts Birds, Cut Flowers, Low Maintenance Zones 3, 4, 5, 6, 7, 8, 9 Propagation Layering, Stem Cuttings Problem Solvers Deer Resistant, Drought Tolerant Where to Plant St. John's Wort There are almost 500 varieties of plants in the Hypericum genus, many of which grow beautifully in hard-to-plant areas. Common St. John’s wort (Hypericum perforatum) adds color and texture to entry gardens, foundation plantings, perennial beds, and mixed shrub borders. There are also low-growing, ground cover varieties of St. John’s wort that can be used in sloped gardens for erosion control. You can even find marsh-friendly types (like Hypericum elodes) that will grow happily alongside bogs, ponds, and streams. Most St. John’s wort varieties thrive in full sun to part shade and moist, well-drained soil, but are tolerant of a wide range of soil types. Shrubs growing in partly shaded sites may have fewer blossoms than shrubs planted in full sun. St. John’s wort spreads rapidly via underground rhizomes and is considered a noxious weed in a number of western states including Washington, Oregon, Colorado, Nevada, Wyoming, Utah, and Montana. Before planting it, consult with your local Natural Resources Conservation Service (NRCS) field office or cooperative gardening extension to see if the shrub is considered invasive or a classified as a threat to native habitats in your area. How and When to Plant St. John's Wort You can plant seedlings or nursery-grown St. John's wort in spring or early summer. To do so, dig a hole about the same size as the plant’s container, tease apart the plant’s roots, and place the plant in the center of the hole. Fill in around the roots and tamp down the soil firmly to remove air pockets. Blanket the soil around plants with a 2-inch-thick layer of mulch and water your St. John’s wort regularly during the first growing season to encourage an extensive root system. St. John's Wort Care Tips Plant St. John’s wort in the spring and you are sure to delight in its sunny summer flowers, autumn berries (on some species), and year-round evergreen foliage. The native North American plant requires little maintenance once established—but watch out for unwanted growth. Light St. John’s wort prefers partial shade conditions but offers the most blooms when grown in full sun. Too much shade can stunt its growth. Soil and Water St. John’s wort grows best in moist, well-drained soil, but tolerates almost any soil conditions including sandy, loamy, and clay soils. It is also not fussy about its soil pH and can grow well in acidic, neutral, and alkaline soils. That said, if you live in an especially wet climate, plant your St. John’s wort in well-draining, sandy soil to ward off root rot—a common issue for the shrub in rainy regions. St. John’s wort is drought tolerant once mature but may need supplemental watering while young. Water your baby shrubs regularly during the first growing season and reduce watering (or rely only on rainfall) in subsequent seasons. Temperature and Humidity The ideal temperature range for St. John’s wort is between 60 and 80 degrees. In hotter climates, the leaves of your St. John’s wort plant may begin to fade, turn yellow, or curl in the sun. You can prevent this by offering the plant shade from the harshest afternoon sun. If you live in an area with cold winters, your St. John’s wort plant will go dormant as temperatures dip below 40 degrees Fahrenheit. Stop watering your plant after the ground begins to freeze and make sure the soil is not waterlogged. If the soil is too wet when it freezes, you may lose the plant to root rot over the winter. Container-grown St. John’s wort plants can be moved to a cool garage or shed but should not be watered. St. John’s wort is not bothered by humidity, but if there is too much ambient moisture, root rot and other fungal diseases may develop. Fertilizer St. John’s wort plants do not require fertilization, but if planted in very poor soil may benefit from an application of organic mulch each spring or fall. Container-grown St. John’s wort plants may benefit from a once-monthly application of slow-release fertilizer (with a low concentration of nitrogen to phosphorus, and potassium) throughout the growing season. Why Are Nitrogen, Phosphorus, and Potassium in Plant Fertilizer? Pruning In some climates, the tips of St. John's wort branches die back in winter. This is not a cause for concern because St. John's wort will bloom on new growth. Simply shear the plants back to live wood in the spring and this hardy perennial will regrow. If you prune your St. John’s wort plants in early spring, they will produce a large crop of flowers in summer. Every three or four years, consider giving your St. John's wort plants a renewal pruning. This involves shearing the plant back to half its height and encourages dense, vibrant new growth. Renewal pruning also helps the plant retain a pleasing, rounded form. Potting and Repotting St. John’s wort is not finicky and can grow beautifully in containers—especially on sunny patios and porches. The size of container necessary depends on the variety, but should, nonetheless, have excellent drainage. For example, a single common St. John’s wort plant should fare well in a medium-sized container (12 to 15 inches) without needing to be transplanted for a while. If you live in an area with cold winters, avoid using terra-cotta containers as they may crack in icy temperatures. Fill your container partway with a good-quality, all-purpose potting mix and add the plant to the center of the pot. Add the rest of the soil and tamp it down firmly to secure the plant. Water your plant thoroughly and place it in an area with full to partial sun. As it grows, your container-grown plant may need extra water. Keep the soil evenly moist (but not wet) until the plant is established. Throughout the growing season, give your St. John’s wort plant a regular application of slow-release fertilizer (but choose a formula low in nitrogen). When winter arrives, consider moving your potted St. John’s wort to a protected area or wrapping the container in burlap to protect the roots from frost. If you need to repot your St. John’s wort, plan to do so after the active growth season. In late fall or early spring, prepare a new container and work the plant gently out of its old pot. Place the plant in its new container and fill the pot with fresh all-purpose potting mix. Water the plant thoroughly and place it back in its sunny location. St. John’s wort can also be grown indoors if it is given ample access to sunlight and is protected from heat sources (like radiators, space heaters, and vents). To prevent root rot, allow the soil of your plant to dry out between waterings and avoid letting water pool in the pot. Pests and Problems St. John’s wort has very few (if any) pest problems. However, in areas with wet winters (or if overwatered), it may struggle with root rot. If wet winters are a challenge in your area, be sure to plant your St. John's wort in well-drained, sandy soil. How to Propagate St. John's Wort The easiest way to propagate St. John’s wort is via seed. You can start them indoors 6 to 8 weeks before the last frost or direct sow them outdoors once the danger of frost has passed. To plant your seeds indoors, prepare a small container with good-quality potting mix and press the seeds gently into your soil, but do not cover them. St. John’s wort seeds need light to germinate. Keep your container in a warm place (about 60 degrees Fahrenheit) and your seeds should begin to germinate in about 10 to 20 days. After the seedlings are 2 to 3 inches long, they can be transplanted to larger containers or the ground outdoors. You can also propagate St. John’s wort via cuttings by selecting a 4- to 6-inch softwood stem from a healthy section of the plant and cutting the stem just above a leaf bud. Remove all the leaves from the lower section of the cutting and dip it into rooting hormone. You can then stick the stem into a grow pot filled with a mixture of perlite and compost. Water your cutting, place a plastic bag over the pot, and put the pot in a warm area to take root. Keep the soil evenly moist until rooting takes place in about 10 weeks. When the plant is sturdy, you can transplant your cutting to a new container or the soil outside. Types of St. John's Wort Common St. John’s Wort esemelwe / Getty Images Common St. John’s wort (Hypericum perforatum) is among the most prolific varieties found in North America—so much so that it is considered invasive in some states and provinces. It typically grows to about 3 feet high and 2 feet wide and features summer blooms, autumn berries, and deciduous, green foliage. Tutsan St. John's Wort Tutsan St. John’s wort (a.k.a., sweet amber or Hypericum androsaemum) features clusters of golden flowers, coppery-brown autumn berries, and oblong green to reddish-purple leaves. It grows best in zones 6-7. Without proper management, it can become invasive, but plant breeders have developed cultivars of Hypericum androsaemum that are genetically infertile, seedless, and non-invasive. 'Mystical Red' St. John's Wort ‘Mystical Red’ St. John’s wort (Hypericum x inodorum) is a semi-evergreen or deciduous cultivar with an upright growth habit that produces star-shaped yellow flowers in midsummer and bright red berries in the fall. It is hardy in zones 6-9 and typically grows to about 2 to 3 feet tall in full sun to partial shade. Marsh St. John's Wort Marsh St. John’s wort (Hypericum elodes), as the name implies, grows beautifully in marshlands, bog gardens, and near ponds in zones 7-9. It has evergreen foliage with small yellow flowers (from June through August) and is native to the wetlands of North America, Europe, and Asia. It fares better in wet soils than other hypericum species, but still prefers full sun to partial shade. 'Sunny Boulevard' St. John's Wort ‘Sunny Boulevard’ St. John’s wort (Hypericum kalmianum) is a tightly-branched deciduous shrub with a long bloom season (from June or July through September). It has a compact, mounding growth habit that typically stretches to no more than 2 or 3 feet tall. It is also among the most cold hardy of the hypericum varieties and can be grown in zones 4-7. Shrubby St. John's Wort weisschr / Getty Images Shrubby St. John’s wort (Hypericum prolificum) bears a lot of similarities to Hypericum perforatum and the two are often confused. Shrubby St. John’s wort has a rounded, compact growth habit (hence the common name) and often blooms with pom-pom clusters of yellow from June through August. Companion Plants for St. John's Wort Bee Balm Peter Krumhardt Like St. John’s wort, bee balm (sometimes called wild bergamot) attracts helpful pollinators and prefers at least 6 hours of full sun exposure each day. It blooms in vibrant shades of pink, red, white, and purple with aromatic leaves that have a citrusy-mint aroma when crushed. Bee balm s hardy in zones 3-9 and known for being deer-resistant and drought-tolerant. Black-Eyed Susan Perry L. Struse Whether in garden beds, window boxes, or small containers, gardeners love black-eyed Susans. It’s not surprising considering how easy they are to grow and the fact that they draw in beneficial pollinators (like bees, butterflies, and birds) while repelling deer and rabbits. Black-eyed Susans thrive in full sun and aren’t fussy about soil (as long as it is well-draining). They are hardy in zones 3-11. Joe Pye Weed Mike Jensen Its name may not sound elegant, but the perennial Joe Pye weed is a stunning statement piece in any garden. The shrub can grow as much as 8 feet tall and is often recommended to gardeners who want the look of a butterfly bush without the invasive tendencies. Like St. John’s wort, Joe Pye weed prefers full sun but enjoys a shady respite from the harshest summer sun. It is hardy in zones 3-10. Alpine Strawberry Peter Krumhardt If you are looking for a pretty, yet functional plant to grow in the understory of your taller St. John’s wort shrubs, consider wild (a.k.a., Alpine) strawberries. The perennial grows in mounds less than a foot tall and produces dainty white flowers followed by sweet, gumdrop-size berries from early summer to fall. Given their tidy growth habit, they are perfect for garden boxes or for lining a walkway and will grow best in full sun and rich, well-draining soil in zones 5-9. Frequently Asked Questions Is St. John's wort an annual or perennial? In the Hypericum genus, there are annual, perennial, and shrub species, but common St. John’s wort is a deciduous perennial shrub. That means the plant has both a bloom season and a hibernation season. It will lose its blooms at the end of the summer and will shed some (or all) of its leaves in the winter but regrow to full glory the following spring. Do all St. John's wort plants produce berries? No. Only some species produce the signature reddish-brown autumn berries. If you want to have a berry-producing shrub, look for varieties like tutsan St. John’s wort (a.k.a., sweet amber or Hypericum androsaemum) or common St. John’s wort (Hypericum perforatum). Why are my St. John's wort leaves turning yellow? There are a few factors that could lead to faded or yellowing leaves. It is not uncommon for leaves to fade during the hottest days of summer, especially if the plant is placed in an area without afternoon shade. Yellowing leaves can also be a sign of overwatering, underwatering, insufficient light, and nitrogen or iron deficiencies in the soil. How did St. John's wort get its name? The name “St. John” refers to the plant’s tendency to bloom around the time of the feast of St. John (the Baptist) in late June. The word “wort” comes from the Old English word wyrt and refers to a plant, root, herb, or vegetable. Was this page helpful? Thanks for your feedback! Tell us why! Other Submit Sources Better Homes & Gardens is committed to using high-quality, reputable sources—including peer-reviewed studies—to support the facts in our articles. Read about our editorial policies and standards to learn more about how we fact check our content for accuracy. St. John’s Wort. ASPCA Toxic and Non-Toxic Plants. Hypericum Perforatum. Common St. John’s Wort. North Carolina Extension Gardener-Plant Toolbox. Common St. Johnswort. Hypericum Perforatum. USDA Natural Resources Conservation Service Plant Fact Sheet.