Marlborough hydroponic lettuce operation Thymebank has expanded its lettuce-growing capacity with the addition of two greenhouses.
Owner Martyn Birch said the increased capacity would enable Thymebank to meet the growing needs of Marlborough and continue to expand its market throughout the country.
The 600-square-metre addition takes Thymebank's total hydroponic area to 6000sqm, set on 2.9 hectares on Hammerichs Rd near Blenheim.
The company produces up to 20,000 lettuces a week for supermarkets and restaurants in Marlborough, which take 35 per cent of the produce, and Dunedin, Wellington and Palmerston North.
"To secure customers you have to be able to supply year round, not just in summer when everything is growing well," Mr Birch said.
"We actively seek customers during winter when every square inch of growing space is full as possible."
In summer, production dropped back to about 60 per cent of capacity, because everything grew bigger and matured in half the time it took in winter.
This gave them the opportunity to spread plant turnover and keep up to date with maintenance, he said.
Mr Birch hires 10 staff and will be looking at taking on more as production increases.
Since taking over Thymebank in 2005, the former Royal New Zealand Navy physical education instructor said there had been "continual growth" in demand for a good quality, year-round supply of lettuce, salad greens and herbs.
The popularity of reality TV shows such as MasterChef and an increase of people seeking healthy diets had fuelled that demand, he said.
"We've expanded by about 50 per cent in the seven years since I took over. We saw the growth in the industry, the population is growing and people always need to eat."
To grow the same number of lettuces outside would require 20 hectares of land and 20 times the amount of water, making hydroponics an environmentally friendly option, he said.