Sweet Peas and Dahlias were the two plants that attracted Keith to horticulture, when he was still a teenager in England. In that environment, breeding of Sweet Peas had become focused entirely on the development of exhibition cultivars which produce blooms with just four flowers, usually of a single colour, per stem and which flower in mid-summer.
Since coming to New Zealand forty years ago and becoming a Kiwi, Keith has developed many new forms of Sweet Pea. Some of these developments are revolutionary, as since 1699 when the Sweet Pea was introduced to cultivation, it had behaved as a pure species. All variation had occurred as a consequence of spontaneous genetic mutation. Many other garden plants owe their diversity to hybridisation between species within the same genus.
For several decades, Keith worked closely with Professor Brian Murray and a series of research students, at the University of Auckland, on the genus Lathyrus. In addition to gaining a much better understanding of the cytology of the genus and barriers that prevent hybridisation between species, a few interspecific hybrids were achieved. The most important of these was a cross between the Sweet Pea Lathyrus odoratus and L. belinensis, which was new to science and was named as recently as 1985. The introduction of different genes to the Sweet Pea has enabled new breeding directions to be explored. Some of these are being offered here for the first time.
Notwithstanding, from the very start of his breeding, Keith has sought to both develop new forms and to preserve types which seemed likely to be lost to cultivation. Although the original Sweet Pea
is bicoloured with a maroon standard petal and violet wing petals, by the 1960s, because of the dictates of exhibition, bicoloured Sweet Peas had almost disappeared.
By going back to ancestral cultivars, which he had helped to preserve, Keith was able to produce a range of bicoloured Sweet Peas, which have been sold, usually in mixtures under names such as Two Tone, Love Match and Melody Bicolour Mix. In this range the standard petal is darker than the wing petals.
From observing a cultivar of the culinary pea Pisum sativum, Keith had the idea to produce a reverse bicolour Sweet Pea. This was much more difficult to achieve than had been the case with the initial bicoloured series, but after about twenty years, the first reverse bicolour Sweet Pea, Leading Light, was made available. This year, as a result of the work with L. belinensis, the cultivar Erewhon is being made available, where the contrast between the pale standard petal and the dark wings is greatly enhanced.
Keith also worked with flaked Sweet Peas, which like the bicolours, were in danger of being lost. These have, for a number of years, been available in mixture as Streamers. Individual colours of improved form are in the pipeline.
Orange Sweet Peas have featured in efforts to produce a yellow Sweet Pea and, following demand from the public, who have seen these at shows like the Ellerslie International Flower Show, Solar Flare was offered for the first time this year, but is now sold out. Orange Sweet Peas are best grown under plastic or in light shade.
Scent is of course the essence of a Sweet Pea. The name refers to the sweet scent. Because, Keith has gone back to ancestral types, including the wild species itself, which are in general much more strongly scented than types bred for exhibition and the eye, rather than nose, most of his raisings have a good scent. However, High Scent, also sold as Brilliant Fragrance, is considered the benchmark against which other cultivars are judged.
In New Zealand it is possible to have Sweet Pea flowers over a long period by growing types that are suited to flowering during winter, spring and summer respectively.
Check out Lunar Sea and Equinox mixture.