Gavin Wollsey of Tapora checking his avocado crop, Northland, New Zealand - Photo Theresa Sjoquist

Avocado growing in NZ – a brief look at an avocado orchard in Northland, New Zealand, and the growing conditions, pollination, pollinisers, and harvesting.

Gavin Woolsey and his wife, Trish have cultivated more than 4,000 avocado trees in a small corner of northern New Zealand which provides the precise growing conditions ideal for the green fruit. Tapora is situated on the edge of Kaipara Harbour and has its own microclimate with warm winds and plenty of sunshine. Because of its proximity to the harbour the orchard is growing in the best possible medium of free draining sandy soil which avocado trees thrive on.

Originally dairy farmers, the couple, with their family, decided to switch to avocado growing when they realised that it would be impossible to purchase any adjoining land to increase the size of their farm. Initially planting 50 avocados one season and 60 the next on a nearby acreage which already had an established orchard of 300 trees, the Woolseys also began planting trees around their house and now have three hectares under canopy.

They were able to produce a commercial crop from grafted trees in four years.

Avocado Tree Growth

Avocados also do well on volcanic soil which provides good drainage. They suffer under frost conditions which can easily kill very young trees but if trees are going to die, it is generally in their first year. Avocado foliage will grow at a rate of 500mm, both out and up, every year and will sustain this level of growth with very little need for water. In conditions where water becomes short the trees bear only as much fruit as they can hold. When fruit is left on the trees, especially under dry conditions, they will begin to flower and produce even more fruit.

Avocado Pollination and Pollinisers

Trish says, “In Tapora spring starts just a bit earlier than elsewhere. Avocados which generally begin to flower around September, bloom in successive stages,” she says, “at least four or five of them. That means there are four or five opportunities for pollination to occur, although the process is complicated by the nature of the flowers which open one day as female and the next as a male.

Avocado flowers, Avocado orchard, Tapora, New Zealand - Photo Theresa Sjoquist

Avocado flowers, Avocado orchard, Tapora, New Zealand – Photo Theresa Sjoquist

“To facilitate pollination in an orchard which is fickle because of the changing gender of the flowers, we use pollinisers to help cross-pollinate. These are other avocado varieties which bloom with intense clusters of flowers and the bees go straight to these ones first. After that, they work their way through the rest of the orchard. Polliniser varieties include Ettinger, Zutano and Fuerte and these trees are planted as part of the orchard, spaced every eight or nine of the main crop variety trees. As the canopy becomes larger, we will need to bring in more bees. They are usually brought in for ten weeks with between six and ten hives per hectare.

“Temperature changes during the pollination stage which relies on warm temperatures, can mean that pollination doesn’t occur, and we’ll have to wait for the next flowering stage.”

Avocado Harvesting

“Normally avocado fruit In Tapora, is able to be picked for harvest from mid-July but the trees will hold the fruit until mid-March without detriment so the Woolseys leave their fruit on the tree until export markets are ready to receive them. More than 80% of the crop is destined for Australia, Japan, and Korea. Just over 10% is taken up by the domestic market and around 6% is used for oil extraction.

Keeping an eye on the fruit development, Woolsey avocado orchard, Tapora, New Zealand - Photo Theresa Sjoquist

Keeping an eye on the fruit development, Woolsey avocado orchard, Tapora, New Zealand – Photo Theresa Sjoquist

Harvesting is a finicky business with the correct pick leaving a 5mm nodule on the fruit to forestall bleeding. With Asia developing as a super market for avocados a new product is being trialed. Fruit is peeled and packaged in plastic, sealed, and then pressurised. The product makes use of slightly damaged fruit, conserving all the good parts.

Source: Theresa Sjoquist interview with Trish & Gavin Woolsey – September 2010

©Theresa Sjoquist