Jankaea

Family Gesneriaceae. It grows on the limestone cliffs of Thessaly (Greece) and on the legendary Mount Olympus.

Plant height 10 cm. Grayish-green leaves are gathered in large rosettes up to 10 cm in diameter. Flowers lavender. Unlike Ramonda and Haberlea, in the temperate zone it is less cold-hardy.

Location: in rock gardens these plants should be planted in slightly shaded spots, preferably east-facing. They look very good against a background of rounded gray or grayish-pink granite boulders.

Soil: made of equal parts turf and leaf mold, decomposed peat, small stones and crushed red brick. Plants are planted so that the lower rosette leaves touch the soil, and are watered. The soil beneath them is covered with thin flat fragments of granite. Plants do not need to be repotted for 4—7 years.

Care: In dry periods (especially in spring) watering is necessary. Before flowering a light dressing with potassium and phosphorus fertilizers may be applied. Nitrogen fertilizers should not be used, as plants may become overvigorous and fail to survive the winter. Sometimes they are severely damaged by cabbage and garden cutworms. Therefore, in spring, as a preventive measure, spraying is carried out with Decis or “Intavir”. When persistent cold arrives, the plants are covered with conifer branches.

Propagation: Like many gesneriads, Jankaea is propagated by daughter rosettes, spring leaf cuttings, and seeds. Offshoots are carefully separated from the parent plant without digging it up; cut sites are dusted with powdered charcoal. They are planted in a prepared spot, keeping about 10 cm between specimens.

In spring, for cuttings leaves with the longest petioles are cut with a razor. Cut sites are dusted with powdered charcoal. Cuttings are placed in a small cold frame in a mixture of equal parts coarse sand and decomposed peat. Leaves are buried to the full length of the petiole, positioned at an angle. The plantings are regularly watered. After 30—40 days roots appear and a miniature rosette forms. The old leaf is not removed until autumn. The following year the overwintered rosette can be transplanted to a new place.

Use: in collector rock gardens.