Will seed-sown passion flowers come true?
Q
Will passion flowers come true from seed and what are the best ones for a sheltered West Midlands garden?
Johnny Wall, via email A
The only seeds that will come true to type are those of species Passiflora such as P. caerulea. Named cultivars will not come true and may not produce any offspring that even much resemble the parent plant.
By the laws of genetics, if one purebred plant crosses with another purebred plant, half the offspring will be a mix of the two gene pools, a quarter will resemble one parent and a quarter will resemble the other. However, any seed-grown plant cannot definitely be regarded as being pure bred, so will already be a genetic mix.
Species plants have strong and stable characteristics that are passed down from generation to generation, but many cultivars are genetic oddities (arising from chance mutations) and their genes are not stable. These are likely to revert to something in their history rather than being passed down.
The Royal Horticultural Society has produced an excellent advice page about growing Passiflora (visit
rhs.org.uk/advice/profile?PID=295).
Your best bet is to look for varieties of P. incarnata and P. caerulea. There don’t appear to be any named cultivars of P. incarnata, but the species is rather stunning and possibly needs no improvement! The RHS Plant Finder lists cultivars of P. caerulea ‘Rubra’, ‘Clear Sky’, ‘Pierre Pomié’ and ‘Chinensis’.
Cross Common Nursery in Cornwall stocks a good section of plants. You can contact them by calling ✆ 01326 290722/290668 or visiting
crosscommonnursery.co.uk.