On the world stage, Bulgaria has overtaken Provence, in France, as the world’s biggest producer of lavender oil, but there is a growing industry in New Zealand, with high quality oil the hallmark. ‘Grosso’, the world’s top oil lavender, dominates. It is a hybrid of Lavandula angustifolia and L. latifolia, but two New Zealand-bred L. angustifolia cultivars, ‘Pacific Blue’ and ‘Avice Hill’, are now making their mark in the oil industry here. All three are suitable for garden use. L. stoechas oil is mainly produced overseas for use in air fresheners.
There are 39 lavender (Lavandula) species, most from the Mediterranean and northern Africa, which explains their tolerance of dry weather and preference for alkaline soils. All hate wet feet, so good drainage year-round is imperative.
Of the hundreds of cultivars, most derive from English (L. angustifolia), fringed L. dentata and French or Spanish lavender (L. stoechas), the latter with distinctive “ears” (coloured bracts) on top of the flower heads. Plants generally are hardy, with L. dentate withstanding extreme cold better than other species. Not for areas that have hard frosts, though, are the fernleaf lavender (L. pinnata) and its cultivars, including popular Aussie introduction ‘Sidonie’ with its 1m flower stems. This intolerance of chilly weather reflects L. pinnata’s homeland, the Canary Islands, where night-time winter temperatures rarely drop below 15°C. Another Canary Islands species, L. multifida is sometimes available, and it, like Allard’s lavender – a cross between L. dentata and L. latifolia – is also sensitive to the cold.
Humidity can be an issue for lavender. ‘Sidonie’ copes well, but lacks the familiar scent (she’s more mint than lavender). For traditional perfume, gardeners in humid places may prefer to grow the L. stoechas Ruffles series, compact (50-60cm) plants bred in Australia for greater tolerance of humid conditions. Look for ‘Sugarberry Ruffles’ (mauve/pink), ‘Raspberry Ruffles’ (pink), ‘Blueberry Ruffles’ (deep mauve/ purple), and ‘Boysenberry Ruffles’ (musky pink with white centres). As well as the familiar lavender in almost every species, flower colour includes violet, purple, plum, pink, green and white. Generally, the darker the flower colour, the better the scent. English lavender has the best perfume, without the camphor-like overtones of other species.
Lavenders make excellent standards for containers. ‘Grosso’ is useful for hedging of about 1m, while L. angustifolia ‘Hidcote’ and ‘Munstead’ are tops for dwarf (50-60cm) hedges.
As with all lavenders, prune after flowering to keep bushes from growing leggy. Old plants that have become straggly can be pruned hard to rejuvenate them, although it may mean a season with few flowers before they bounce back.
Picking a colour can be challenging, as there are so many choices. One of the deepest violets is ‘Foveaux Storm’, bred in Invercargill ‘Helmsdale’ is purple/plum, as is ‘Avonview’ ‘Purple King’ lives up to its name, while ‘Pukehou’ and ‘James Compton’ are popular, too and ‘Blue Prince’ is lavenderblue. Blue ‘Dilly Dilly’ is a L. x intermedia hybrid. The most dramatic pink has to be L. pedunculata ‘The Princess’, introduced in 2013, although the pink “ears” of ‘Jester’ and ‘Bella Rose’ are appealing. White L. stoechas cultivars like ‘White Queen’, ‘Snowman’ and Southland-bred ‘Lily’ tend to look greenish.
For a truer green bloom, hunt down L. viridis, a Moroccan native sometimes sold as yellow lavender. Some cultivars of L. stoechas have twotoned flowers. ‘Tiara’ is one of the best, with white bracts above the purple flowers Nelson-bred ‘Pat Leigh’ has lemon-yellow ears on purple flowers and ‘Lavender Green’ is green and white. L. angustifolia cultivars include purple ‘Blue Mountain’, ‘Hidcote’ and ‘Munstead’ grey-blue ‘Otago Haze’, pink ‘Rosea’ and white ‘Blue Mountain White’. Contradicting the old song, lavender is not always blue, dilly dilly, but worth a place in every garden.