In the conservatory or greenhouse it is better to put a little heat around the roots of tender plants than to raise the air temperature, which only encourages the already stressed plants to photosynthesis, putting added strain on the root system and causing the leave to dehydrate and wither.
Passion flowers are easy to grow. They need a place with partial to full sun, and will adapt to most well-drained soils. During the growing period, the soil should be kept moist, but with good drainage, this will ensure a good flowering and growth. Beginning in late august, let them dry out a bit between two waterings but never completely. Apply a balanced fertilizer from early spring and then again 6 to 8 weeks later.
Passion flowers should be planted in early spring. They will benefit by the addition of compost into the planting hole. If grown in pots, use a loam-based potting soil and keep it slightly pot-bound. Passion vines tend to flower more freely when confined. Top dressing rather than repotting is sometimes advised and this should be done annually in spring. Repot Passion flowers every 2 years in late winter or early spring, always allowing the plant to recuperate for a week in a cool shady area before putting it back out in a sunny location. Prune Passion flower vines at about 15 cm from the soil level or to 6-8 buds, in early spring, and a few weeks prior to repotting. This should encourage flowering on the new growth.
Passion flowers can be propagated by softwood cuttings of fully mature wood in early summer. Cuttings will take 3 months or longer to root. They can also be grown from seed sown in spring. Seeds will germinate in a seed compost of any type, at 13-18 Celsius degrees (55-64 F). Germination may take up to a year. It is better to keep the young plants indoors until the following spring, and then plant them outside in their permanent place. You can also use the layering method in spring or autumn.
Passion flowers also make excellent container grown plants for indoor, grown in bright light, but never in full sun, is best suited to a sunny room or a greenhouse. Ideally, it should have 4 hours of bright, direct sunlight daily throughout the year. However, it may sun scorch in summer if placed too close to a south or west window. The plant may be taken outside during the summer.
Even they enjoy bright light, they prefer lower temperatures around 12.7-18.8 Celsius degrees, especially in winter. They will tolerate slightly warmer temperatures in summer but this may cause infestation with spider mites and will loose their attractive shape. Cooler temperatures in winter, around 10 Celsius degrees, will allow them a rest period.
Plants make rapid annual growth each year as this clings with tendrils, plants won’t damage brickwork or fences but they need suitable supports to grow on so it is better if possible to plant it next to a chain link fence or on a trellis. Passion flowers bloom from mid to late summer and after a warm summer it is possible to form large orange-yellow fruits. Those can be left on the plants for decoration. Even they are edible they do not have a special flavor.