There are also species in the plant species Passiflora that are hardy and can therefore simply remain outside in the winter. Below is a large part of the species that are hardy with a small description.
Blue Stripper
P. Blue Stripper is a hybrid made by Henk Wouters. He has P. Incarnata and P. Umbilicata crossed with each other, resulting in this beautiful deep blue flower. In addition, it is quite strong and can therefore tolerate some frost. Exact temperature is difficult to say, but the plant must be able to survive down to -8 degrees. This plant can therefore be planted in the garden, but certainly in the first winter still cover the roots and the rootstock a little.
Caerulea
Many a garden wall or fence is brightened up by the fresh flowers of the P. Caerulea, followed by orange fruits. In addition, the fresh green leaves are added, which gives almost no problems. P. Caerulea comes from Argentina and since the winters there are quite cold, it does well with us. That is why many hybrids (crossings) have been made with this species, in order to obtain more hardy varieties. They are still working on this and there will be more to come. You can give young plants a winter cover the first year. In the garden you can P. Caerulea pretty old words; 10-15 years is not a rarity.
Caerulea “Pierre Pomie”
This variant of the well-known blue P. Caerulea was found by the French passion flower enthusiast Pierre Pomie and fortunately has the same properties in terms of hardiness and flowering. Can simply overwinter in the ground in winter. Only cover the roots with organic material in its first year of life in hard frost. The leaf may show some yellowish spots, which is a characteristic and therefore not a disease.
Caerulea “Constance Elliot”
This is the white form of the well-known natural color P. Caerulea. If you can give it a place where it can grow well and is sheltered, it can certainly become quite old (15 years is not a rarity). It depends a bit on the spring how quickly it will grow and flower again after the winter. Furthermore, a plant that you hardly have to worry about. After the first year, you no longer need to apply winter protection. Temperature: -14 degrees C.
Ely
This is another somewhat older hybrid from Henk Wouters, with P. Caerulea as one of the parents. He has also acquired the winter hardiness characteristic of this, albeit to a slightly lesser extent. Is not such a striking appearance, but certainly nice to plant it in the garden, or by a P. Caerulea to grow. Minimum temperature: – 10 gr.
Incarnata
This is one of the oldest species in culture. That’s because it is so strong and because the green parts of the plant are said to have medicinal properties, which are said to have a calming effect. In addition, it is very beautiful and floriferous. This species will disappear completely above ground in winter, to make young shoots from the roots again after winter. Cover the plant a little during the winter the first year. Minimum temperature: -10 gr.
Incarnata Alba
P. Incarnata Alba is a passion flower that is ideal for planting in the garden against a fence or wall in the garden. It is rightfully one of the strongest passion flowers. In cold winters it will largely die off above the ground and then sprout from the roots again in the spring. Young plants that are outside for the first year are best covered at the roots with organic material (leaves, peat litter, straw). Remedies are extracted from the leaves of Incarnata that are said to have a calming effect. Is very bloom-friendly with beautiful bright white flowers.
Incense
It has been quite a few years since this beautiful hybrid came onto the market and is still very popular due to a number of positive characteristics. Beautiful bright and large flowers of about 10 cm and also reasonably frost resistant. Nevertheless, it is advisable to cover the base of the plant with organic material in the winter. It is a pity that the plant carries a latent virus, which can slow down the growth of the plant in some periods. Once the plant is growing well again, the leaves will also become greener and fresher. So don’t think it’s a lack of nutrition. Minimum temperature: -8 gr.
Naviculata
P. Naviculata has been renamed; namely P. Tucumanensis. This happens more often with botanical species, because on closer inspection the name is incorrect. A very nice strain for our climate, because the plant can tolerate quite a bit of frost. The plant can be planted against a wall or fence. The first year, if the root system has not yet developed in this way, cover some more with organic material, which is excellent for maintaining the structure of the soil underneath.
White Mirror
Nice strong hybrid made by Henk Wouters in 2007, which can tolerate some frost. So can be planted in the open ground, only cover at the base in severe and prolonged frost. Nice dark leaves and can grow into a large plant. Blooms fairly early and with numerous flowers that have a somewhat blue discoloration in the beginning, but become whiter under the influence of daylight with the typical blue ring. Certainly when the plant gets a bit older, it will be more and more floriferous.