About the Riverside® Passiflora

Simply the best

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:-

Free flowering

All the selected Riverside® hybrids are free-flowering, producing flowers at every node over a period of many months, often May-November.

Riverside free flowering


The solidity of the striking polyploid flowers lends itself to more intense colours that stand out strongly against other plants around them.

Riverside striking colours

Size matters

All Riverside® Hybrids compare favourably with Passiflora caerulea, producing bigger, stronger longer lasting flowers.

Riverside size advantage


Hardiness is approximate but these should survive occasional dips down to -8°C, 18°F or USDA zone 8b.

Riverside hardy hybrids

‘Breeding hardy Passiflora by Myles Irvine, Riverside® Passiflora breeder.

The Plantsman (RHS) New Series Volume 9 Part 3 September 2010
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Passiflora RHS PLantsman

Passiflora Online Journal ISSN 2046-8180.

Ten issues to date, articles by academics and enthusiasts worldwide. Fabulous photo galleries. Publisher and Editor Myles Irvine, Riverside® Passiflora breeder.
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Passiflora Online Journal

‘Pure Passion’ Plant Profile

on Myles Irvine, Riverside® Passiflora breeder, by Philip Clayton
The Garden (RHS) Volume 135 Part 9 September 2010
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Pure Passion RHS The Garden

Investigation of Passiflora hybrids using flow cytometry

L.A. King and M.S. Irvine
Passiflora (2010), 20(1):pp. 5-11
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Passiflora hybrid cytometry