Cranberry Harvesting on the West Coast

how to grow cranberries

Wild Ruby Cranberry

While whitebaiting in Hokitika last winter, I came across an intriguing pamphlet for a local cranberry farm and decided to plan another trip down the coast to catch some cranberries, (easier than whitebait). I’m picking that like me, most New Zealanders wouldn’t know much about the fresh version of this well known American import. Cranberry juice, dried cranberries and cranberry jelly are the limit of my knowledge.

The first thing I learnt when I called to arrange a visit is that cranberries are an autumnal fruit. In New Zealand they’re harvested from mid April through until mid June. The American autumn harvest coincides with a raft of high days and holidays, which may be one reason why the cranberry has become such a culinary institution there. Thanksgiving turkey without cranberry sauce would be like new spuds without mint.

how to grow cranberries

So in early May, I headed south and spent a beautiful sunny afternoon harvesting with Stephen and Dianne Sheaf at “Wild Ruby Cranberries“, just south of Greymouth. While we worked, they shared their story. They started out planting in 2007 and eight years later I got the feeling that I was standing there with New Zealand’s foremost experts on the cultivation of true American cranberries.

Not that they would class themselves as that. Their expertise is not the “read it in a book” type. It is expertise gained through doing. In the early years they did rely on advice from other New Zealand growers but as they worked with the plants, they learnt what actually worked for them on the ground, rather than what worked on paper – sometimes at great cost to their patience and wallet.

fresh cranberries

Doing anything new always has its challenges and cranberry growing is pretty new to New Zealand. But Dianne and Stephen are certainly doing something right. A visit to the farm from the senior technical advisor to Ocean Spray, the main American cranberry consumer brand, gave them hope that they were on the right track. He had never seen cranberries of such a deep red hue and large size in North America.

If New Zealand could supply high quality fresh cranberries for the American market in their off-season it could be a valuable export crop. However there are still a few technical issues to overcome. The cranberry likes a certain soil acidity with a ph of between 4.5 – 5.5 and growing temperatures lower than 25°C. They don’t like rich soils and nitrate fertilisers, which tend to promote runner growth at the expense of fruiting.

Contrary to popular belief, they don’t like wet feet. The crop is flooded for ease of harvesting in the US because the hollow berries float to the top and can be easily skimmed off their thin stems. But during the growing season the plants are kept damp and are grown in quite free draining sandy soils.

how to grow cranberries

Wild Ruby cranberry farm is planted on an ancient coastal swamp made by a filled in lagoon. It has a thick layer of silt over pure gravel. Stephen and Dianne cleared the gorse and painstakingly prepared the land with 10 cm of sawdust on top of the silt, then a top coat of sand before planting out 100,000 cranberry plants at 23 cm apart.

They have planted several varieties for successive cropping and to evaluate which performs best. Bergman is early and ripens around March. Pilgrim ripens from mid-April and Stevens is about 2 weeks later. Of the three, Pilgrim has been the most prolific performer and forms the bulk of the 1.54 tons harvested this season. These are true American cranberries, not to be confused with the plant that has been marketed as the “NZ Cranberry”. This is actually a Chilean guava with a tiny fruit and a bushy growth habit, very nice but completely different to true cranberries as you can see below.

fresh cranberries

The plantings started fruiting within 3 years and have been relatively pest free. The lovely matted carpet is a favourite place for ducks to park their bums in the sun but they don’t seem to eat the berries. Rabbits don’t stay long because any burrow they dig fills with water. Weeds seem to be the main enemy, and after a few years of painstaking hand weeding, Dianne reluctantly resorted to an annual application of spray, but far enough out from fruit set so that the crop is spray free.

Cranberry plants are long-lived, which is a good thing if you’ve got to plant 100,000 per hectare, and once established a bed will go on fruiting for many years. The plants knit together forming a low-growing, dense web of thin branches coated in small leaves. It is like walking on a thick spongy carpet. Wild Ruby cranberry farm borders a quiet country road, and after a few years of driving past the farm, one of the locals remarked to Stephen that “they’re not growing very fast are they”.

cranberry plants nz

And as far as crops go they are indeed pretty compact. No climbing ladders, staking or netting is required. But getting a harvest from this paddock of shag-pile is far from effortless. The first challenge is the runners. For some reason NZ cranberries are good at sending out runners, long runners that need to be pruned off each season. Fruit is borne on short upright stalks and the more of these you can encourage the better. Runners just run and don’t produce fruit so they have to come off. Stephen invented and built a lethal looking, pruning machine of rotating blades that goes through the bed, winding up the runners and decapitating them.

The next challenge is harvesting. Again Stephen and Dianne have a machine for the job. It looks a bit like the heavy reel mower I used to run along behind to mow my Granddads lawns. And it does work on the same principle, lifting and cutting the berries, sending them up a little conveyor into a sack at the back.

cranberry growing nz

Next the berries have to be sorted to remove the foliage from the crop using baskets and frames in a two stage process. In good weather this is done down in the beds and then the harvested cranberries are taken up to the shed for washing, drying and packing.

how to grow cranberries

So can you grow them at home? Is it feasible to have your own little cranberry patch?  Yes you could if you had the right conditions.  But if you don’t I’d recommend buying some during the season from Wild Ruby. The fresh berries keep well in the fridge for up to 12 weeks and they also freeze very well.

They are a definite seasonal delicacy and one that comes at a good time of year when all the other berry treats have shut up shop. They are a culinary berry though and in the next blog I’ll show you the fun I had with them in my kitchen when I got them home.

how to grow cranberries

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8 comments

  1. Cheryl Lichtwark

    Wait for the next instalment, and thank you for giving a good insight to cranberries.

    1. Thanks Cheryl, they’re fascinating little fruit for sure. I’m enjoying cooking with them.

  2. These look like a great idea for putting as the groundcover in a forest garden – particularly as it looks like they tolerate you walking on them? I have one large patch of ground and some smaller areas that would be idea, if I can find some suitable plants.

    1. Hi Sophie-Lee, yes they would make a good ground cover but I think they might need some sun so not sure about the forest garden idea.

  3. Is there any change of being able to tell where I can get hold of some fresh cranberries as i wont to make some christmas pies that need 300grams of fresh and 30 grams of dried , thanks Roy Rieid

    1. Hello Roy, that sounds nice – this time of year you might get fresh frozen ones but no fresh ones grown in NZ – not sure if anyone is importing fresh ones – give Diane a call at Wild Ruby.

  4. Hi, Would cranberries grow in Amberley?

    1. Yes most certainly Lorraine – they would do well I imagine – perhaps a bit of water over the growing season might be required.

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