New Zealand lavenders by Simon Charlesworth
'Lavender's blue dilly-dilly'... and pink, white, cerise, crimson, burgundy and yellow! The range of lavenders available to the gardener is mind boggling. Many of today's popular lavenders are the result of discoveries on nurseries. Nowhere more so than in New Zealand where lavenders are not indigenous. With their blazing hot summers and kinder winters, lavenders grow prolifically and hybridize promiscuously. The near-perfect climate gives rise to superb lush growth and splendid flowering, difficult to achieve during a growing season in the UK.
There has been a plethora of forms making their way to these shores, predominantly Lavandula stoechas
hybrids with flamboyant sterile bracts atop.
Some 40 or so have been gathered together at Downderry. The first of these 'Helmsdale' and 'Marshwood' were introduced in 1995 from a nursery on the south island of New Zealand. The former has a compact habit with burgundy flowers, the latter is taller and has the most enormous flowers with large dusky pink sterile bracts.
Others have followed including 'Pukehou' (1999) with magnificent broad pale purple sterile bracts, the short and prettily coloured 'Rocky Road' (2002) the luxuriant 'Regal Splendour' (2001) with its purple flowers and velvety purple-crimson bracts, Tickled Pink' (2002) with its mass of frilly pale pink sterile bracts and 'Ballerina' (2003) with white sterile bracts turning pale pink with age.
The species and subspecies that make up the parentage of the New Zealand L. stoechas
cultivars are native to the Mediterranean. Lavandula stoechas subsp. stoechas is found throughout the Mediterranean region, while L. stoechas subsp. pedunculata
and L. viridis
occur naturally in Spain and Portugal.
With the exception of a very few, all are crosses between L. stoechas subsp. stoechas
or L. stoechas subsp. pedunculata
with L. viridis
. The stocky L. stoechas subsp. stoechas
has no flower stem to speak of, while the pedunculata subspecies has a 20cm stem or peduncle. Both have smooth stems. Lavandulala viridis
has a hairy 10cm stem and yellow-green flower heads. The New Zealand hybrids invariably have hairy stems.
It is generally understood that L. stoechas subsp. stoechas
is always found on acid soil in the wild and L. stoechas subsp. pedunculata
always on alkaline soil. Which way L. viridis
swings the hybrids is more difficult to assess and is the subject of on-going trials.
Frost hardy as they are, surviving a temperature of -5°C and at a push -10°C in a very favourable position, they are not reliably tolerant of our wonderfully wet winters. It is therefore, best to grow them as specimens or in small groups of 3 or 5 or to grow them in pots, but not en masse.
The great advantage of growing stoechas lavenders is their remarkably long flowering season. Expect them to flower on-and-off from May to September. To keep plants under control halve the height after the first flowers are past their prime. Plants will then bush out and bud-up on side shoots. When subsequent flowers go over remove the flower and stem only, with possibly a very light prune to shape in September.
More recently L. angustifolia subsp. angustifolia
cultivars have arrived. 'Lavenite Petite' (2000) - short and mid-purple 'Crystal Lights' (2000) - very short and white 'Coconut Ice' (2000) - appropriately named with pink and white flowers and very short and most recently the staggeringly sumptuous 'Melissa Lilac' (2003) with powder purple flowers and incredibly vigorous and luxuriant growth.
Incredibly, many of the early cultivars from this country were taken out to New Zealand in the 1950s by a lady called Avice Hill. This has proven to be rather fortuitous, as after she migrated, lavender cultivars got into a terrible pickle in the UK with rampant mis-naming. It has only been possible to unravel the muddle by referring back to those plants taken to New Zealand all those years ago. Particularly ironic is that the cultivar called x intermedia
'Old English' which Avice purchased from a nursery in Seal near Sevenoaks in Kent, was one of those plants. We brought it back to Kent in 2000!
It was a wonderful opportunity to travel to New Zealand in January 2000 to see lavenders flowering when the time was available to observe them in some detail instead of squeezing in observations and assessments during a short and hectic season in the UK. Two collections that I had to visit were Virginia McNaughton's near Christchurch and Peter Carters' Ploughman's Garden and Nursery. Virginia is a botanist and everything was pristinely displayed in neat well-tended rows as one might expect from a scientist. It is she who has provided a home for the lavenders that came from England in the 1930s and who has also introduced cultivars from New Zealand, to the UK.
Peter's approach is quite different. His nursery and garden house a burgeoning profusion of lavenders. He has an intuitive sense of where the different cultivars are growing and a keen eye for spotting something a little different. It is a particular credit to both these individuals that there is such a rich diversity of lavenders to tap into.
Several of these imports have Plant Breeder's Rights attached to them and deservedly so. However, the clamour for 'new' plants among nurserymen and public alike has led to some dubious Plant Breeder's Rights applications, where distinctiveness of cultivars is in the minutiae and firmly in the 'splitting hairs' camp. This is the case with the majority of the other New Zealand cultivars and other cultivars we have in the collection.
It would be most advantageous to all concerned if more breeders or discoverers of potential new cultivars were to approach National Plant Collection holders for their expert opinion. These custodians of such a vast and accessible plant bank, with the detailed knowledge of their genus, enable a more thorough assessment of the nuances between cultivars than is often available elsewhere.
Article reproduced from Plant Heritage Volume 10 No.2 Autumn 2003