The history of Passion flower hybrids
The earliest known Passion flower hybrids were created in the early 19th century. Since that time hundreds of hybrids of these fabulous flowers have been created, of which sadly many have been lost over the years. Few are hardy however and fewer still are polyploid, Polyploidy means having more than the usual two sets of paired chromosomes. It is one of Nature’s ways of speedily adapting to environmental change. Our advanced breeding techniques are now starting to produce polyploid Passion flowers with three or even four sets of chromosomes per cell. This gives easy to care for plants with increased vigour and larger, stronger flowers which often stay open for several days.
Riverside® Hybrids have the following advantages for both nurseries and home gardeners:-
All the selected Riverside® hybrids are free-flowering, producing flowers at every node over a period of many months, often May-November.
The solidity of the striking polyploid flowers lends itself to more intense colours that stand out strongly against other plants around them.
All Riverside® Hybrids compare favourably with Passiflora caerulea, producing bigger, stronger longer lasting flowers.
Hardiness is approximate but these should survive occasional dips down to -8°C, 18°F or USDA zone 8b.
Some relevant articles both by and about Myles Stewart irvine & the Riverside® Hybrids:
‘Pure Passion’ Plant Profile
Myles Stewart Irvine, Riverside® Passiflora breeder,
by Philip Clayton
The Garden (RHS) Volume 135 Part 9 September 2010
Investigation of Passiflora hybrids using flow cytometry
L.A. King and M.S. Irvine
Passiflora (2010), 20(1):pp. 5-11