Bridestowe Lavender Estate, Nabowla, Tasmania

Joan Head
Editor, The Lavender Bag

From The Lavender Bag 23 (May 2005)

I have always wanted to visit Tasmania and in particular this lavender estate, having heard much about the contribution of Tim Denny and his family to the development of superior lavender oil at Bridestowe.

Tasmania itself is a fascinating place. Twenty per cent of it is a World Heritage Area, containing the island's four largest national parks of mountains and forests. The varied coastal stretches range from inhospitably rugged and treacherous coastlines to gentle, scenic bays.

On the uphill part of the return journey, lithe young people passed us on their way down and mortifyingly overtook us on their way back up.

We stayed a few nights in the Lake St Clair wilderness, enjoying the bushwalking, the local wild life and a boat trip the length of the lake. Since we were within driving distance of the west coast, we decided to visit Queenstown and Strahan. What an experience! Approaching Queenstown, 40 k north of Strahan, we entered a totally different landscape. In the 1880s mining began on Mt Lyell, first for gold, then copper and silver. The hills were stripped of rainforest - by the 1920s three million tonnes of timber had been felled to feed the furnaces. Over the years, pollution from the copper smelters killed off any remaining vegetation, bush fires were fuelled by the sulphur-impregnated soil and dead stumps, and rain washed away the exposed topsoil, leaving bare, rocky hills and deep gullies. Copper smelting had ceased in 1969 and we saw the beginnings of scrub and small tree regrowth on the slopes. It remains a mining area - ten years ago, the company Copper Mines of Tasmania reopened the Mt Lyell mine and extracts about 8000 tons of ore-bearing rock each day. We drove on to Strahan, an area well-known for the Huon pine which in the early years of the colony was much sought after for boatbuilding because of the water-repellent qualities of its oily wood. Prized now by furniture makers and wood turners, Huon pine featured in the woodwork shop on the esplanade along with items carved or turned from sassafras and myrtle. In an area round the back of the shop was a container of off cuts, a dollar each.

The north east of the island has been deforested and has long been an agriculturally rich area, with vineyards, beef farms, dairy herds and market gardens of vegetables. It is said that any potatoes eaten in Australia almost certainly have been grown and processed in Tasmania, while the dairy farms produce butter and many of the cheeses. Softwood trees are also grown and harvested for the timber industry. It is in this area, near Nabowla, that Bridestowe Lavender Estate is to be found. Our visit was in the second week of January and harvesting had just begun, somewhat later than usual. There wasn't much to indicate the presence of the farm before we turned in to the gates, but from the car park at the top of the slope there is a breath-taking view of over a hundred acres of lavender in flower against a backdrop of mountains in the same shades of purple.

Tim Denny's father, C.K.Denny, had worked for F.S. Cleaver and Sons, the biggest producer of toilet soaps and perfumery in London. In 1911, after qualifying as an accountant, he was employed to straighten out the company's affairs. During his years there, he also became a highly skilled perfumer. Cleaver and Sons was sold to Unilever in 1921 and Denny decided to emigrate to Australia with his young family rather than accept the offer of managing the company for Unilever. He wanted to find a new source for lavender oil, knowing that the French industry could not satisfy the demand for fine lavender oil. Denny took with him seeds of Lavandula angustifolia collected in the French Alps.

He chose Tasmania as his eventual destination because it approximated in climate and soil conditions to the French Alps, being on the same relative latitude. There was also no native lavender to hybridise with the plants he was planning to grow from seed. In 1922, having acquired land in north east Tasmania, he sowed the first seeds and by 1924 had distilled oil, sending it to London for analysis. It was declared of good quality and camphor-free, "at least equal to a good French oil". More land was cleared of bush and a distillery was built in 1930. Denny began exporting his oil in 1935.

When the two sons returned home from war service the business continued to expand with the emphasis on mechanisation and more land was bought at Nabowla, a few miles away. This was managed from 1948 until 1990 by Tim Denny, who became well known through his writings about lavender growing and oil production. The estate now comprises 200 acres, 120 given over to lavender growing.

The original seed brought from the Alps produced several flower colours in all shades of blue and purple to pink and white. There was considerable variability too in vigour, form and longevity of the plants, as well as variations in quality and yield of oil. Over the years 487 genotypes were reduced to 13 cultivars, chosen for their vigour, superior oil, flower colour and for a spread of flowering - early, mid-season and late. Five strains have since been selected from those 13. David and Judy Roberts, the managers of the farm, told us that the darkest purple of these five is reserved for the cut flower trade. Joining the tour offered by the farm, we learned that none of the varieties is named, only within the business and these remain a closely guarded secret (in fact no lavenders are sold from the estate and lavenders on sale elsewhere as 'Bridestowe' do not originate here).

Lavandula angustifolia is the only species of lavender grown, presumably to keep the strains pure and prevent any hybridisation. We saw the distillation process but were asked not to take photographs. Sitting in the tearooms at the top of the slope, it was easy to pick out the different types of lavender. Planted in blocks of the same variety, some were paler in flower colour than others, some were just coming out of bud and others had reached full flower and were already being harvested.

As we strolled along the rows of lavender, we saw and heard many bees at work. Enormous (by our standards) hives stand at the end of the fields and honey is collected. We were told it doesn't taste of lavender!

By careful selection of lavender types, the farm is now able to produce five tonnes of lavender per hectare, instead of two tonnes, with a yield of 60 kg of superior oil per hectare, compared with 20 kg of average quality oil. In the early days, harvesting was done by hand, using the sickle, but by 1949, Tim Denny had designed the first effective lavender harvester. This was a complicated machine, prone to breakdown, but it reduced the time taken to complete the harvest. With a sickle, one man could harvest 300kg per day; with the machine, productivity was increased to one tonne per hour. Following further improvements to the harvester it now has only three moving parts, one man doing the job of 93 hand operators. The flowers are harvested direct into a steel cartridge on the machine which can now cut and deliver 2½ tonnes in an hour, packed and ready to distil.

Lavender does not compete with weeds therefore total weed control is essential. Weeding by hand used to take three man days per acre and this had to be done twice a year. Now small amounts of a weak herbicide are used to control the young weeds. At or before harvest six people hand weed the rows as well. The only predator is a small moth whose larvae attach to the young shoots in the spring, leading to defoliation and eventual death of the plants. No insecticides are needed as the local bird population keep the grubs under control.

I was interested in the propagation techniques- the adult bushes are divided and the slips planted out in winter using a machine. Planting follows the contours of the land, the curving rows maximising soil and water conservation. Newly planted lavender takes four years to reach the size for full production. Small quantities of an artificial fertiliser are used, allowing lime, potash, nitram and super phosphates to be returned to the soil. In addition, the waste products of the distilling process are returned to the fields. Bushes are pruned annually after flowering. If left to themselves they can become leggy after seven years or so. Pruning techniques ensure that the bushes now last as long as twenty flowering seasons. Rotational crops such as canola, peas, broad beans and barley or oats are grown for two years in overworked lavender patches. These areas show up as green patches in the lavender landscape.

After harvesting, a tractor takes the cartridge of cut flowers to the distillery. At the busiest time there is a shuttle of two tractors each taking a full cartridge away from the fields and returning with an empty one. At the distillery, the oil is extracted by steam distillation. Each cartridge has a wire mesh base and is inserted into the still with a steam-tight lid clamped on.

Steam is generated beneath the cartridge and passes through the flowers, causing oil to vaporise. The oil vapour together with the steam passes through a water-cooled condenser, reducing the vapours to a liquid state. The liquid then enters the separator where the oil flows to the top and pours out into a receiving vessel. The water runs away from the bottom of the separator and is discarded. Each cartridge holds a quarter of tonne of flowers and can be distilled in seven minutes, yielding three litres of oil per tonne.

This raw oil needs to mature for several years. It is put into stainless steel drums, the air expelled and replaced by an inert gas. Eighty-five per cent of the oil produced is exported to Europe, North America and other parts of Australia. Dried flower production supports cottage industries locally. For this, the flowers (those deep purple ones) are harvested at their best, spread out on a tarmac area, dried rapidly then vacuumed up. Apparently the dried lavender scent remains for ten years. Many of the products made from the dried lavender are on sale at the shop.

We spent a week in Tasmania and saw only a fraction of its beauties. It was certainly an eye-opener to me and we hope to explore more of the national parks next time. And we'll be returning to Nabowla.