How to grow Passion Flower

Passion flowers may look exotic,  but in fact they are easy to grow, and Passifola caerulea, commonly known as the Blue Passion Flower is hardy with an abundance of showy flowers in the summer. The Blue Passion flower requires little or no attention  and is  tagged green wheelbarrow.  The variety illustrated in the first image top left is variety P.caelea . This is the most popular variety grown in UK gardens and is sold widely on line and in garden centres. It is popular in part because of the practical reason that it is hardy ** H4 which means -5 to -10.  I have seen Passion flowers grow in colder, more exposed areas and it does seem to survive lower temperatures if it is planted with it's roots in well drained soil on the dry side.  

When Passion flowers are grown in a colder area they tend to lose most, if not all of its leaves in winter, and are therefore semi ever green in colder areas.  The colder and more exposed your garden, the more care will be needed in where to plant a Passion flower to afford it maxium shelter. In a reasonably sheltered spot, on well drained soil, a Passion flower plant should require no additional attention or care over winter. 

The most universally hardy, easy to grow and widely sold is the Blue passion flower. The less hardy varieties, such as  Passiflora caerulea 'Constance Elliott' P. violacea unless grown in a very sheltered part of the UK will need to be container grown and brought under glass over winter.

How to Grow Hardy Passionflower.

A good time to plant a Passion flower is early Autumn when the soil is still warm, and the autumn rains will water the plant until it is well established. Equally a Passion flower can be planted in spring or summer, in which case it will be necessary to check and ensure the plant has plenty of water until established, after which it will look after itself. An ideal planting place for Passion flower is a sightly sheltered spot, say on a fence next to patio and Passion flowers will survive most of our winters and the flowers are eye catching. It will grow in full sun and will tolerate some shade.  Passion flower will grow in any soil alkaline or acid and is will tolerate moist soil provided it is well drained.

Passion flower does not require pruning, but P.caerulea the most commonly grown can be vigorous, and can be pruned after flowering to keep to shape and within its allotted space and size. Passion flowers have tendrils, which means it is self supporting and will climb and twine. However, in common with many tendril plants it can get into a tangle and is best trained so the branches and flowers are spaced out. A trellis is ideal for a Passion flower to catch onto.  When first planted to get the passion flower to grow into a good shape take 3-5 strong stems and train them with at least 2 stems running laterally. If you need to prune it do so after flowering, which will be early Autumn time cutting back to a neat framework of buds. If a Passion flower becomes over grown you can cut back harder, it's vigorous and will grow back but as commonly the case when cutting back hard, flowering maybe reduced the following year.

An additional advantage is that Passion flowers are attractive to wildlife as well. Follow this link for more about wildlife friendly plants

Passion flowers require little or no maintenance and if grown in ideal conditions can be vigorous, up to 8-12 meters and so it needs to be planted in a largish spot. Although it is said passion flowers will grow in a container, and by necessity the more tender varieties have to be container grown,  I think the common blue variety is too vigorous and better in the ground unless there is no alternative. Mention is also made of growing passion flowers in a conservatory. My experience of conservatories is that in the summer they reach very high temperatures which makes it a hostile environment for most plants. (An exception are Pelargoniums which tolerate conservatory conditions very well, but are the exception unless your conservatory is very well ventilated, cooled and with a good amount of shade.) The average very hot conservatory will bake most plants.

Passiflora caerulea 'Constance Elliott'  is hardy to H4 illustrated top centre, which is happier in a more sheltered spot and a little more tender than the blue variety.  It has lovely white flowers which have the additional benefit of being scented. It will need winter protection.

The third image on the right, P.violacea is more tender still and will only withstand temperatures down to 1.C and will need glass or greenhouse protection over winter.

The latin name for Passion flower, is Passiflora, so called after the Passion of Christ.  It is said that the stigmas and anthers represent the nails on the cross and the wounds. 

There are lots of attractive climbing plants to choose from for your garden. For more  information, images and growing advice about climbing plants. 

Green wheelbarrow means easy to grow

Most garden centres in UK offer P. caerulea for sale, illustrated top left,  a very good variety with the RHS Award of garden merit which is always a reliable indicator and a green wheelbarrow showing it is easy to grow

RHS award of Garden Merit