From vibrant red hypericum blooms to the resilient hypericum calycinum, these plants bring charm to any garden. But what happens when issues like fungal infections, pest attacks, or hypericum diseases strike? Whether you're tending to hypericum hypericoides or managing hypericum anagalloides, we’ll guide you through the challenges and help you keep your plants thriving.

Hypericum Diseases and Care Tips

Hypericum hypericoides and similar species are prone to fungal issues like Botrytis and other hypericum diseases. Protect your plants by reducing humidity, avoiding condensation on leaves, and ensuring proper airflow. Learn effective treatments to keep your hypericum healthy year-round.

Foliage Damaged In Winter due to Windburn

A severe windburn may damage hypericum foliage during the winter, but these shrubs usually regenerate in the spring. Minimize damage by surrounding plants with protective material such as burlap or agricultural fleece. If this is an annual problem, move the plant to a more protected location.

Cottony Masses or Bumps on Twigs means Scale Insects

White, cottony masses or brownish bumps on hypericum stems clustered in crotches or close to buds are likely to be scale. These insects feed under protective shells. Female scale shells are gray and pear-shaped, and the male shells are smaller and narrower. The size of a pinhead, these pests sucks plant sap and secrete honeydew that, in turn, encourages sooty mold on the foliage and the branches. Scrape the pests off plant surfaces with a fingernail or a cotton swab dipped in rubbing alcohol.

Spray severely infested plants with a mixture of rubbing alcohol and insecticidal soap every three days for two weeks. Add one-teaspoon alcohol to a pint of ready to use commercial soap spray. To control heavy infestations, cut and burn affected branches. In late March or early April spray plants that have chronic scale problems with "superior" dormant oil, before growth starts. This will smoother over wintering scale.

For more information see file on Controlling Scale.

Plants Look Sickly because of Root Knot Nematodes

Nematodes are whitish, translucent, wormlike creatures 1/125 to 1/20 inch long--barely visible to the naked eye. Hypericums infested with nematodes look sickly, wilted, or stunted, and show yellowed or bronzed foliage. They decline slowly and die. When they are pulled up from the soil their root systems look poorly developed, even partially decayed. Roots have knots, or galls, on them. The effects of nematode activity are most apparent in hot weather, when limp plants do not seem to revive after the heat of the day has passed.

Control nematodes by adding lots of compost (especially leaf mold), if it is available, to the soil to encourage fungi that attack nematodes. Drench the soil near affected shrubs with dilute fish emulsion that is toxic, or repellant, to nematodes.

Powdery Spots on Leaf Undersides indicates Rust

A rust disease caused by a fungus causes pale areas to appear on upper hypericum leaf surfaces, with brownish powdery spots directly beneath. Remove infected leaves as soon as possible. Remove and destroy diseased plants and all nearby yard debris before growth starts in the spring. Treat the disease by spraying foliage periodically with wettable sulfur starting several weeks before the disease normally appears in the spring. Space plants widely apart for good ventilation, and avoid wetting foliage when watering.

For more information see file on Controlling Fungal Disease.

Leaves Covered With White Powder caused by Powdery Mildew

Powdery mildew caused by fungi attacks shrubs growing in shaded spots with little air circulation, especially in the southern states and the Pacific coast. Leaves are coated with a thin powdery deposit, later becoming discolored and dropping off. Spray foliage of affected shrubs thoroughly with wettable sulfur once or twice at weekly intervals starting as soon as the whitish fungus coating the leaves is visible. Collect and discard all aboveground yard and garden refuse in the fall to prevent contagion.

For more information see file on Controlling Fungal Disease.

Foliage Burned due to Dog Urine

Dog urine may discolor foliage and even kill branches of low growing plants along property borders. Spraying foliage with an anti transpirant gives some protection. Screen target plants or spray them with an aerosol pet repellant.

People also ask:

What are the adverse effects of Hypericum?

Hypericum, or St. John’s Wort, is generally safe but can cause side effects. Common issues include nausea, dizziness, fatigue, and photosensitivity, where skin becomes highly sensitive to sunlight. Rare but serious effects include serotonin syndrome when combined with certain medications. Hypericum may also interact with medications, reducing their effectiveness. Always consult a healthcare professional before use, especially if you are pregnant, breastfeeding, or on medications.

Why is my Hypericum dying?

Hypericum plants may die due to overwatering, leading to root rot, or underwatering, causing crispy, wilting leaves. Fungal diseases like rust and powdery mildew, pests such as aphids or spider mites, or poor drainage can also stress the plant. Ensure the plant has well-draining soil, proper light, and is watered correctly. Address fungal issues with fungicides and improve airflow around the plant. Adjust care based on symptoms for a healthy recovery.

Is Hypericum poisonous to humans?

Yes, Hypericum is mildly toxic to humans. Ingesting large amounts or coming into contact with its sap can cause nausea, skin rashes, and increased sensitivity to sunlight. Severe reactions, such as serotonin syndrome, may occur if combined with specific medications. Avoid ingestion and handle the plant carefully with gloves. If poisoning is suspected, seek medical attention immediately.

How long does Hypericum last?

Hypericum, as a perennial plant, can thrive for 3-5 years with proper care, and some species may last longer. In cut arrangements, Hypericum berries typically last up to 14 days, while flowers can remain fresh for up to 18 days with clean water and care. Outdoors, Hypericum blooms from late spring to early fall, and self-seeding ensures longevity in the garden even as individual plants age.