Darragh McCullough: Why I’m investing in polytunnels and others should think about it too

It’s all about polytunnels.

Admittedly, this may be of no interest to farmers that only grow cereals and grass, but hear me out.

It’s on my mind because we started erecting two more polytunnels last week.

Until three years ago, I had never grown as much as a weed under cover before. But I knew that if I wanted to broaden the range of flowers that we offer, tunnels or glasshouses were the next step.

A modern high-bay glasshouse costs anything north of €1m per hectare to build, and even the most basic versions will cost €500,000 per hectare.

Polytunnels aren’t new technology, but their relative cost, and the appetite for more exotic produce has made them a seriously profitable option for farmers.

If you are erecting them on a scale, you can erect them for about €100,000 per hectare.

They can’t be heated or controlled with the same precision as a glasshouse, but we had daytime temperatures over 20C in them during the sunny days in March.

It means that you have plants bursting out of their seams during the shoulders of the year when there isn’t a hope of getting anything out of the fields.

We’re cropping Alliums and Iris in the tunnels that won’t be ready for harvesting outdoors for another month.

But flowers are only the tip of the iceberg. McNally’s Family farm in north County Dublin is a classic example, with an amazing range of chilli peppers and mexican-type green tomatoes and salad leaves being pumped out of their ‘cold’ tunnels without any artificial heat right into December.

I was determined to minimise the investment in my first tunnel, scouring the locality for a old secondhand tunnel and putting it up ourselves, only calling in a pro for the final day of battening on the plastic cover to get it ‘drum-tight’ as those in-the-know like to say.

It still cost about €5,000 when all the costs were added in, but I finished up with a very respectable 40m long, 6m wide tunnel. I went with a quite high 4.4m structure, which generated a lot of debate over how exposed it would be since there is no trees or hedges protecting it from heavy winds.

But I wanted a big air-mass in the tunnel to reduce the flux in temperatures, and provide a healthier growing space for the plants.

I also have a 1m high mesh along the sides, with additional plastic panels that we can nail on the outside to cover up these vents during the winter months.

While the Spanish tunnel is the cheapest version of polytunnel, I opted for a fixed plastic cover since I reckoned that we wouldn’t bother stripping off the plastic every winter. That call triggered another series of heated exchanges about tunnels being blown off over the Irish sea during every storm, but three winters later, it is still standing without any airborne incidents to report.

What I’ve learned in the interim is that there is 40pc funding available for these types of structures from the Department of Agriculture’s Horticultural grant scheme, including your own labour.

So even if the new tunnel ends up costing me €8,000 for example, it works out cheaper than the secondhand version.

In most cases, planning permission isn’t required. And it doesn’t really matter how good your soil is because you can build up raised beds, or grow in crates instead.

I was impressed to learn that D-Plant, who supplied me the tunnels, have 20,000 members on their Irish Polytunnels Facebook page.

Membership has ballooned from less than 2,000 prior to Covid presumably because the general public have also cottoned on to the world of possibility that these structures open up.

For commercial growers, revenues of €100,000/ac for an acre of well managed polytunnels are achievable, and should clear the cost of the tunnel within a couple of years.

That beats the pants off any land investment I’ve ever seen.

Darragh McCullough runs a mixed farm enterprise in Meath www.elmgrovefarm.ie

Online Editors