Clematis montana 'Jenny Keay'

Clematis montana 'Jenny Keay' arose in 1991 as a chance seedling raised by New Zealand breeder Alister Keay, who named the variety after his wife in 1995. Its roughly 6 cm double to semi-double flowers show narrow, pointed sepals in white with a delicate pink tint, set off by pale green stamens – a refined flower shape that stands out from the simple flowers of most montana varieties.

'Jenny Keay' produces a single, abundant flush of flowers from May to June on the previous year's wood. It is a compact variety at around 200 cm – considerably more restrained than the often several-metres-tall growth of the wild species, which makes it appealing for smaller trellises, arbours or pergolas on house walls. It thrives in both full sun and partial shade and can be grown in any aspect.

The variety is reliably winter-hardy (zone 7, down to about -17.7 °C) and vigorous in growth. As it belongs to pruning group 1, cut 'Jenny Keay' back to about 75 cm right after flowering in June – this encourages strong new growth and a rich flush the following year. Since the flower buds sit on the previous year's wood, avoid a later, drastic cut-back.