Regarded as one of the most sought-after herbs due to its beautiful flowers, its alluring scent and its extensive uses, lavender is a crop with a lot of commercial potential.
Believed to originate from the Mediterranean, Middle East and India, most lavender is commercially grown in the Provence region of France, which has mild winters and warm, sunny summers which are ideal for lavender production.
While production costs are much higher in New Zealand when compared with countries like Bulgaria, which is one of the world’s largest producers, New Zealand has a niche market due to our unique combination of climate and soil and resulting high-quality oil.
World production of oil comes from a mix of three species.
- Lavendula angustifolia the narrow-leaved lavender. Commonly known as English lavender.
- Lavendula latifolia the broad-leaved lavender. Commonly known as spike lavender.
- Lavendula intermedia a cross between angustifolia and L. latifolia.
These selections are commonly known as lavandins. In general, lavandins selections are lower priced, but produce the most essential oil per kilogram of dry matter and account for about 80 percent of the oil produced worldwide. The rest tends to come from English lavender which is priced more highly, with only a small amount from the spike lavenders.
The oil is used as a disinfectant, an antiseptic, an anti-inflammatory and for aromatherapy. An infusion of lavender is claimed to soothe and heal insect bites, sunburn and small cuts, burns and inflammatory conditions and even acne. Lavender oils are also used for internal medical conditions, including indigestion and heartburn.
Lavender oil is said to soothe headaches, migraines and motion sickness when applied to the temples. It is frequently used as an aid to sleep and relaxation. Typically sold in small 5 or 10 ml bottles, retail prices range from $2.40/10 ml ($240 per litre) for lower-quality oil up to $10–20/10 ml ($1,000–2,000 per litre).
Dried lavender flowers are used extensively as fragrant herbal filler inside sachets – to freshen linens, wardrobes and drawers. As an air spray, it is used to freshen in practically any room. Dried lavender flowers have also become popular for use at weddings as decoration, gifts and as confetti for tossing over the newlyweds.
There is a huge range of lavender varieties. It is recommended that those interested in growing lavender commercially talk with local growers with similar climates before deciding on which species to pursue. Trial plantings are recommended, to help decide which varieties best suit the property.
You can expect to pay $1.50–2.50 for a lavender plant supplied in a 5-cm tube. Depending on the variety chosen, you will need to buy 6000 to 10,000 plants per hectare, depending on the variety chosen.
Once the ideal variety for the property has been selected, growing lavender is relatively straightforward. Plants are produced using semi-hardwood cuttings taken in either autumn or spring. Young plants should be placed in the field after the last spring frost. Irrigation and weed control are the two most important tasks as the crop develops.
Harvesting time will be late December/early January for the angustifolia varieties, and late January/early February for the lavandins (Grosso, Super etc.) but can vary from region to region and from year to year as climatic conditions determine when the crop is ready.
Manual harvesting requires intensive labour, however a mechanical harvester is a significant investment and is not really justified until there is a large area to harvest. There are herb harvesters available for purchase, and some growers have made their own versions.
Some people cut by hand using sickles, hedge trimmers or serrated-edged knives (scissors and secateurs tend to become seized up from the resin in the stems). It is important not to allow the cut lavender heads to fall onto the ground – they must be kept free of other vegetable matter as this may affect the oil when it is distilled with the lavender. Pruning of the bushes can be carried out straight after harvesting or left until there is more time available, as long as they are pruned before the first frosts set in.
It is preferable to distil on the same day as harvest, as the crop must be dry (even of dew) when harvested. It should be stored in conditions where it won’t sweat. Some people store lavender in jute wool fadges or cotton duvet covers. Others spread their lavender out on the floor of a shed so that the field heat can escape, until they can get it to the still. A still can be a major capital investment, and unless you intend to be a major producer, it is probably better to get access to someone who will contract distil the crop. At present, there are several stills available throughout the North and South Islands.
The ultimate aim of most lavender growers is to make an income from oil production, and that involves marketing. Some produce oil for use in their own added-value products for sale, and some sell to brokers as a commodity.
Most modern lavender plantings are machine harvested. The plant material is ready for harvesting when approximately 80 per cent of the individual florets have opened and some are starting to senesce. The oil content in the plant is highest at this stage.
The heads are then steam distilled to extract the oil. Not many growers have their own distillation unit. Cooperatives working together can share the distilling capacity or more commonly pay a larger grower to process the plant material.
After preparing the ground and planting, most work on a lavender block is done mechanically. This means requirements for a tractor, mower, spray unit, harvest machinery, bins, etc.
Larger-scale operations may require packing shed, distillation equipment, etc.
Site selection is crucial. Lavender prefers a well-drained soil with a pH level of 6–8. Plants will not tolerate water-logged soil conditions. Even though lavender is a low-growing plant, shelter from the wind is advisable. This will reduce the amount of damage to the plants and subsequent disease problems. Be careful with design to allow the plants to get the maximum amount of sunshine during the growing season.
Lavender is tolerant of cold winters providing the soil is free draining. However, late frosts in November and December can cause loss of flower buds that will affect crop output. All lavender species originate in the Mediterranean areas of Europe; however with plant breeding, varieties have been developed that will grow in nearly every climate.
The expense and labour involved in weed control is frequently underestimated, and crop yields can suffer badly. Some small growers have planted into weed mat and this has proven to be an excellent option for reducing the amount of herbicides and hand-weeding needed during the season. Although it is expensive initially, it pays for itself in the long term. Weed mat will also protect the roots of the young plants from rabbits who will otherwise have a field day after the planting out.
Water is essential during the establishment phase of a lavender block. It is also necessary when the crop is developing its flower heads in the period leading up to harvest. If the crop doesn’t receive irrigation or natural rainfall over this time, the oil yields can be significantly reduced.
No research is available for nitrogen leaching of lavender, but it is not considered to be high. Any land use change to lavender planned for the Lake Rotorua catchment would need to be modelled for nitrogen leaching.
Yields vary depending on location and variety. English lavender has been known to produce oil at about 1.0–1.5 ml of oil per kg of fresh flower (around 25 litres/ha) and lavendins have been known to produce oil at 10–25 ml per kg of fresh flower heads (around 140 litres/ha).
A wholesaling service is provided by Essential Oils of New Zealand. There is also the option of developing a brand and marketing directly to the end user.
Given the estimated production figures listed above, if English lavender retails at $10 per 10 ml bottle or $1000/litre, gross revenue would be $25,000 per hectare. For lavendins retailing at $2.40 per 10 ml bottle or $240/litre, gross revenue would be $31,600 per hectare.
NZ Lavender Growers Association
NZ Lavender Growers Association researches, develops and promotes high-quality New Zealand essential oil and associated products. The association works with growers to achieve a defined standard of NZ lavender oil and to continue with further research projects that will benefit the industry.
Growing and harvesting lavender: http://www.lavender.org.nz/all-about-lavender-plants-oil-harvesting
Lavender farms can be found at http://www.lavender.org.nz/new-zealand-lavender-trail.
‘Lavender Blue’, New Zealand Geographic (https://www.nzgeo.com/stories/lavender-blue/)