Aaron’s beard, Hypericum calycinum, is also known as St. Johnswort. Aaron’s beard is a woody perennial often used as ground covers. Find facts and info on growing and caring for Aaron’s beard.
Aaron’s Beard Facts and Info
This woody perennial grows rather fast and will spread rapidly. Aaron’s beard is grown in Zones 4-9 and will reach 24” high by 36” wide. It prefers partial to full shade making it an ideal plant for shady areas of your landscape that does not get much sun. It likes moderately fertile, moist, well-drained soil with a pH of 5.5-7.0.
Hypericum calycinum has bright yellow flowers with pronounced stamens that appear fro midsummer to midautumn. Evergreen leaves are dark green on top and lighter below. Plants are invasive and should be placed on banks, along fence lines, and other areas where they can ramble.
Care of Aaron’s Beard
Plants should be planted 36” apart in spring or fall. You can apply slow-release granular plant food at time of planting. Water the plants deeply when the soil becomes dry. In summer and winter, you can apply a 3” layer of vegetative mulch to help retain soil moisture. When the mulch decomposes, it will add organic matter back into your soil.
The plants can be cut back to the ground in spring to remove winter-tattered shoots and leaves. In the South plants often are affected badly by the heat and will drop their leaves in summer.
Propagation is done by division. Divide the plants in spring by digging around the root clump and lift. Be sure to use a spade that is sharp enough to penetrate through the root system. Reset portions that have healthy roots and top shoots, then water and mulch.
Pests and Diseases include scale, rust, and leaf spots.
Some species such as tutsan (H. androsaemum), have become commonly used in cut flower arrangements because of their ornamental seed capsules that change from greenish yellow to red and eventually to black.
Golden cup St. Johnswort (H. patulum) is an evergreen shrub that bears clusters of 2” yellow flowers in summer.
‘Hidcote’ and ‘Sungold’ are popular cultivars.
H Xmoseranum is a hybrid of Aaron’s beard and golden cup St. Johnswort. It has 3” yellow blooms.