Green vegetables and hydroponics combine nicely when consumers are close but productive land is scarce

Green vegetables are best produced close to where people live. But nature often needs a little help to make it happen. That is where glasshouses and hydroponics come into play. It is a combination that allows green vegetables to be grown throughout the year in most parts of New Zealand while still being aligned to nature.

Some of my readers will know that I am a fan for the mountains of the Otago Lakes District. Also, for more than 50 years I have been a skier, becoming even more enthusiastic as the years go by, with skiing now providing both joy and adrenaline for a retired mountaineer.

Each year I spend time in the Wakatipu Basin skiing across and down the slopes from daybreak. But not every day is a skiing day, and one recent such morning I spent time with Erika Colby, one half of the Erika and Andrew Colby team at Crystal Gardens. 

Erika and Andrew grow premium lettuces for Queenstown and across to Wanaka using their own hydroponic recipes. They have been building up their experience and expertise for close on 30 years. When they started, hydroponics was still in its infancy.

The essence of hydroponics is that plants get the moisture and essential minerals from gently flowing water. There is no need for soil. Plants start their life in a support bed of tiny water-absorbent rock particles such as vermiculite and quickly burrow to the water below with its carefully mixed supply of nutrients.

Lettuce varieties at Crystal Gardens. Photo: Annette Woodford

Hydroponics is a system that works well for quick-growing green leafy vegetables, but it is not the way to grow crops high in energy density such as potatoes, carrots or onions.

One of the reasons hydroponics works so well for green leafy vegetables is that the leaves have a low energy density.  The plants have no high-energy-storage organs at this stage of their lives, and so they can be grown at high density, and within a hydroponics system are easily transplanted as they grow. Give them a mix of water and essential minerals, plus sunshine and moderate warmth, then keep them away from pests, and they will look after themselves.

Of course, in practice it is never quite that easy. Glasshouses are fundamental to maintaining the correct range of temperature and humidity. The Wakatipu basin is renowned for its high sunshine hours which is a big help.

One of the challenges of this season has been estimating demand for green vegetables. It was easy to figure out that there would be no overseas tourists, but Queenstown and Wanaka are very much alive with locals. The school holidays were crazy up at the ski-fields. Also, Queenstown is still very much a construction town with many hundreds of trades people working flat out. As one local said to me, there are hundreds of builders, building houses for builders to live in. There are also more hotels and shopping centre still being built. But can it go on?

Riding the chairlifts early in the morning on First Tracks provides great opportunities to talk to the locals. This is the time that the locals are up there, together with the serious racers, while most of the short-term tourists are still rubbing the sleep from their eyes.

First Tracks is not a time for beginners. The snow can be very firm and people are skiing fast. It costs extra to be out at this time, but as an add-on to a season-pass, it is a great investment for the enthusiasts. In contrast, tourists can easily spend more than a season’s First Tracks add-on in a single day with meals, accommodation, transport and lifts.

One of my fellow travellers on the chair this year was a builder from the Waikato who, 18 months ago, bought a Queenstown service station. He reckons that business is down, but he is surviving, and it’s great to be able to pop up the hill for those early morning runs. He plans to stay.

Sometimes I ride with a hotel room-attendant who zooms up and down the slopes each day at a great speed before heading off to work mid-afternoon. Another of my chair-mates was a former financial analyst from Sydney who bought a Lake Hayes property at the time of the GFC back in 2009. He reckons that the Wakatipu Basin is his home for life, and where his bones will be buried.

Last year I chaired with a Queensland surf-shop owner who commutes each winter to the Wakatipu Basin. This year with COVID he is missing. But there is a Japanese couple who come here every year, including this year, having done their quarantine back in June.

There are diverse accents to be heard, including a man from Seattle who now dabbles as a ski instructor on the days he is not child-minding while his American wife works as a speech therapist. There are also Brazilians and Argentinians. There are also folk from England, including a yachtie couple who made it in before COVID and are now hunkering down.

Ski-field regulars are a polyglot type. They are different from the short-term visitors. To a large extent they are people who have decided there has to be more to life than going to the office each day. Some are rich and others live from hand to mouth. These early morning regulars have only one thing in common and it is the joy they get from carving down the slopes before the crowds arrive.

 Returning to those lettuces, the genuine outdoor types also tend to be keen on nutrition. So, it all helps in creating a good market for a wide range of lettuce varieties.

Urban folk often think that the future of New Zealand agriculture can be based on vegetables. But it does not work that way because export opportunities are very limited. Also, green vegetables, although important for health, are about 95 percent water. They don’t travel well.

However, growing green vegetables close to consumers is a great way to undertake local production in areas where productive land is limited. The great thing about hydroponics when applied to green vegetables is that it is a technically efficient production system, based on controlled application of water and the necessary nutrients, together with sunlight and a controlled environment. It is a great example of where science, the environment and hard work can come together. 

As for my own Wakatipu Basin adventures, they have come to a temporary end. On my most recent day upon the mountain, something went astray and I awoke to find myself together with a now battered helmet in the Coronet Medical Centre, being prepped for a visit to the hospital. While skiing steep and somewhat fast, it seems I may have hit what skiers refer to as a lump of ‘elephant snot’, or alternatively I may have hit a frozen lump known as a ‘death cookie’ sitting frozen in amongst the glistening snow. It can happen. But all is well that ends well, and I will be back next season.

*Keith Woodford was Professor of Farm Management and Agribusiness at Lincoln University for 15 years through to 2015. He is now Principal Consultant at AgriFood Systems Ltd. His articles are archived at http://keithwoodford.wordpress.com. You can contact him directly here.