Passiflora PRINCEPS

Passiflora is very popular among flower growers due to its lack of caprice and rapid growth. It prefers bright lighting; however, during midday summer hours it is better to shade the plant from direct sunlight to avoid burns. On south-facing windows it exhibits maximum flowering, grows wonderfully on west and east windows, and on north-facing windowsills or in light shade it grows, but blooms very sparsely. It can be taken outdoors during the warm season. In the winter period, supplemental lighting with grow lights is desirable. It requires a constant flow of fresh air, but does not tolerate drafts. In the summer period, a comfortable temperature is 20–25 °C (68–77 °F); in heat exceeding 30 °C (86 °F), the plant quickly loses its ornamental value, yellows, dries out, and blooms very poorly. In winter during the dormancy period, it needs a cool rest at a temperature of 10–15 °C (50–59 °F); without providing such conditions, it may lose its leaves and even perish.

Watering must be systematic and abundant from early spring to late autumn. The soil should always be moist; waiting for it to dry out is unnecessary, and water stagnation in the saucer should not be permitted. In the winter period, watering is reduced to 3-4 times a month. In the summer period, it requires daily misting with soft water. It is important that during misting the plant does not receive direct sunlight to avoid burns, so it is better to carry out the procedure in the evening. A warm shower can also be very carefully arranged once every 7-10 days without damaging the fragile stems. With insufficient air humidity, the appearance of red spider mites and bud drop is possible.

During the spring-summer period of vigorous growth, Passiflora is fertilized every two weeks alternately with organic and mineral fertilizers for indoor flowering plants at half dosage. The optimal ratio of elements in the fertilizer is: 4 parts potassium, 2 parts nitrogen, and 1 part phosphorus. Before feeding, the soil is necessarily moistened. It is also recommended to apply foliar feeding once every month and a half. In winter and under conditions unfamiliar to the plant, it should not be fertilized.

Transplanting a young plant is carried out every year in spring, and a mature one once every 2-3 years. It is recommended to increase the container size only slightly, because the more room the roots are given, the longer and lusher the liana will be, but the sparser the flowering. A mixture of equal parts of turf soil, leaf mold, peat soil, and sand is used as soil. It is best to repot the plant into a new container using the container transfer method without disturbing the soil ball. Pruning is performed during repotting, watering is reduced, and misting is discontinued.

The shoots must be provided with a sturdy support and their growth direction corrected in a timely manner, as they grow quickly and lignify just as quickly. In the first year, Passiflora builds up main stems, forming the foundation of the future liana. Flowers appear only on young shoots; therefore, starting from 3 years of age, an annual spring pruning of young shoots at the base of the plant and 1/3 of secondary branches remaining from the previous year and bare is recommended. After flowering and fruiting, main branches are shortened by 3/4 of their length, and bare secondary branches are cut out completely. It is important not to prune down to the level of the main stem; leaving 4-5 cm (1.6-2 in) of the shoot is necessary. Pruning should be carried out gradually, in several steps; this way, die-off of a large number of small roots will not occur, and consequently the plant will not be subject to root rot and risk of death.