The St. Johnsworts make up a large group of herbaceous and shrubby plants widely distributed over the northern hemisphere.
A number of the herbaceous kinds and some of the moderately hardy shrubs of the group have received considerable attention in plant catalogs, but the value of some of the hardy and ‘dependable woody. Species are rarely appreciated.
The best of these is golden St. Johns-wort, Hypericum frondosum, which develops into a roundish compact shrub 3’ or 4’ feet in height. It is native in the Southeast, from South Carolina and Tennesee to Texas. William Bartram, the famous son of a renowned father, was one of the first to notice this shrub.
The Philadelphia plant explorer found it growing on the stony banks of a creek west of the Flint River in southern Georgia in 1776. Bartram was much impressed with the habit and beauty of the plant, and he described it briefly in his journal.
Hypericums Yellow Flowers
Hypericums are easily recognized by their showy bright yellow flowers with five petals and a round tuft of golden stamens in the center. The leaves are covered with small translucent or opaque dots. These are most easily observed by scrutinizing the lower surface of a leaf against the sky or a light.
The beads are relatively evenly spaced but in no particular pattern. As in the case of similar glandular dots of other plants, they are connected with the production of certain oils, which have a part in the growth processes.
The leaves of golden St. Johnswort are oblong, from 1” to 3” inches long, and a distinctive metallic blue-green. Typically, they are spaced in twos on the branchlets, but occasionally, pairs of smaller leaves are arranged with the giant team at a node.
A distinctly formal effect is produced by this shrub’s dense and twiggy framework, which is enhanced by the picturesque habit often taken by mature specimens.
In this species, more titan than most others, there is a tendency to develop a single trunk, and the dense crown arises from the top of a single stem 6” to 18” inches high. Frequently the box becomes twisted and bent and may even rest horizontally on the ground.
This interesting effect is increased by the unusual reddish-coppery bark, which continually peels off in thin papery layers.
To all these virtues, golden St. Johns-worts add the beauty of showy flowers at a season when flowers are not abundant in shrub plantings. Individual bloom often measures 2” inches across, and at the center of the rich yellow petals is the showy puff of golden stamens.
Blooms After Summer
The flowers start soon after summer and continue for about two months if the weather favors them. Specimens growing in partial shade remain in bloom longer than others growing in full sun. All in all, the summer picture is very pleasing.
Small pear-shaped fruit capsules follow the golden shower of bloom, and these ripen in late summer, scattering hundreds of tiny seeds. The provident gardener will salvage some seedlings and plant them in some convenient corner.
These reserves can be substituted for the original plants or used in new plantings if the situation requires it. It is also very fortunate to have a small stock for plant exchanges with friends, as this shrub rarely fails to interest those who see it.
Golden St. Johnsworts are perfectly hardy and survive temperatures well below zero. Fahrenheit without injury.
However, it must be mentioned that individual plants in gardens are not long-lived in the usual sense, though a planting as a whole can be permanent so long as a small amount of attention is given to selecting the volunteers mentioned above for replacements.
It is reasonable to count on plants remaining in good condition and making an attractive feature in a garden planting for eight or ten years. Sooner or later, injury is likely to come from ice and snow. Or even from high winds due to the dense crown of large specimens.
Once injured, they seem to deteriorate gradually despite repairs and fertilization, and rather than retain plants past their prime, it is advisable in most cases to remove the old specimens and start with new ones saved for just this purpose.
Hypericums rarely meet with setbacks due to plant diseases or insect pests. It is interesting to surmise if the oils secreted in the tissues may not have a beneficial effect.
Some European species, less notable for decorative plantings than our native ones, have had impressive reputations for healing and curative properties. Still, these attributes are more or less discounted today.
Soil well-drained and still moderately moist is best for growing these St. Johnsworts. The particular soil type seems unnecessary so long as it is not heavy clay.
In dry situations, mulching with compost or leaves is beneficial in conserving the moisture necessary to develop good bloom and extend it through the summer. Plantings may be made at any time with good results, but the period of active growth in spring and early summer is scarcely advisable unless the plants are pruned hack severely.
44659 by Ben Blackburn