Three years ago Kirsty Harkness was prompted to start trialling hemp as an inter-row crop in three Blenheim vineyards. Today she is on the path to some highly positive results that may do much to elevate the crop as a valuable addition to other vineyards and orchards around New Zealand.
“When I became vineyard manager in 2010, I could not find earthworms in our soil. The bulldozers had not replaced the topsoil in many places when the vineyard was developed, and we realised we needed to start adding organic matter to build it back again,” she said.
A few thousand cubic metres of compost later, she had mastered the tricky art of brewing a good blend, combining components including waste grape skins from Marlborough wineries, saw dust, molasses and lime. Other trials had included mussel shells – plentiful but rejected after proving to be a smelly failure in one batch.
“The soil samples we took were very encouraging, but I also wanted to look at some other crops we could plant within the vineyard that would contribute to our sustainability and profitability,” she said.
Other organic vineyards in Marlborough incorporate plantings of blue borage, phacelia, red clover and buckwheat – all strong flowering plants that draw bees.
“But it wasn’t until I looked at hemp as not only a way of breathing life back into the soil, but also as a potential secondary revenue source that I really got excited,” she said.
The appeal of hemp was that it does not require spray treatments and has a taproot that can extend a metre down into the soil, extracting nutrients and moisture that are pulled to the surface, to the benefit of surrounding plants.
“And bees particularly like it, the pollen provides an exceptional food source for hives,” she said.
With co-funding from the Government R&D agency Callaghan Innovation, she was able to establish hemp did not have a negative impact on the primary crop, grapes. Its positive contribution also comes from being an “in-situ” compost source.
“Hemp has a significant level of biomass as a crop,” she said.
“Once it is mulched in the vineyard, it takes about nine months to break down, with that mass adding significantly to the level of organic matter, without the fuel and energy required to bring in compost from elsewhere.”
She recounts how the trail had to be paused until it was determined by scientists that the miniscule level of cannabinoids within the plant would not be absorbed into the vines then the grapes, and ultimately deliver an unintended, enhanced vintage.
“But cannabinoids are not water soluble, so we were able to prove to the Ministry of Health and MPI they could not be absorbed into our wine – unfortunately,” she said.
The research on hemp as a mulch compost is due to be published in a leading North American viticulture magazine next year.
Meantime, just as it has proven positive for the soil, Harkness is also demonstrating the positive effect the plant can have for humans.
She had been casting around for products to help ease her allergies to skincare products.
“I had found hemp seed oil was good for my skin, but it smelled pretty disgusting when it oxidised,” she said.
She partnered with essential oils blending expert Gabrielle Zander and between them they found the dehulled hemp seeds could deliver the oil’s benefits when blended with other active and more pleasant smelling oils.
These added active oils also work as natural preservatives and stop the hemp oil from oxidising.
“We have a Whanganui company that can dehull the seeds and create us a beautiful golden coloured oil,” she said.
Working with Auckland-based lab company Shieling Laboratories, they have developed the ideal blend of hemp, jojoba seed, sweet almond, squalene and grape seed oils for their first skincare product under the recently launched Hark & Zander brand. This product is capable of being both a moisturiser and cleanser.
“We are intending to release one new product each month next year, with 15 products in the range, through retail and online,” she said.
Exports are in the pipeline, with the brand trademarked in China, Australia, United States, Europe and United Kingdom.
Harkness sees the brand riding a surge in global interest in New Zealand at present.
“There is a significant segment of the global cosmetic market for which natural and sustainably sourced skincare products are prized, and being able to source these from New Zealand provides us with a significant advantage,” she said,
As a member of the NZ Hemp Board, she has seen interest in hemp grow quickly, with NZ hectares increasing tenfold from 200ha to 2000ha in only three years.
However, she is conscious one of the bigger barriers to its use both in orchards and as an extract is the confusion with recreational cannabis.
“Hemp is a variety of the cannabis sativa plant species, but it is grown for industrial uses, containing negligible amounts of the psychoactive compound THC.
“For NZ to take full advantage of the billion dollar export potential, we are going to need to work to grow mainstream acceptance of a product first used for industrial purposes thousands of years ago,” she said.
