Figuring out how to do agroforestry in Ireland

by Siobhán Lavelle

January 2022

I forgot who had given me her number. Having made my way to the small town of Kilrush in Co. Clare, I walked and hitched up a hill overlooking the sea, battered by the wind, to what I hoped was the right place.

The area in front of the house was dense with the skeletons of trees, it being early January. I could still hear the ferocious wind, but all was still in here. I looked around and saw the site was surrounded by thick belts of large trees. This was a cosy little micro-climate. I knocked on the front door and waited a while, receiving no answer.

It was then that I began to pay attention to the soft sound of branches snapping, which could have been an animal grazing. I walked a little way into the wooded area and soon saw the bright colours of a woolly jumper that must have belonged to a human.

I had found her, Astrid Adler, the owner of Ireland’s oldest food forest, breaking up branches for firewood. She is completely self-sufficient in firewood and almost self-sufficient in food, tending 1.5 acres alone, part-time.

‘I’m shocked at how close these trees are planted,’ I told her. I had studied horticulture at the National Botanic Gardens and plant spacing was a law you didn’t break. More recently, I’d been reading about forest gardening and putting it into practice on a very small scale. This involved deprogramming from my conventional education – combining plants with beneficial relationships instead of planting blocks of one type of plant, mixing trees with vegetables and herbs and not disturbing the ground to remove every weed. Still, spacing seemed like a sticking point.

‘You can plant them as close as you like,’ she assured me ‘if they get too squashed, you just cut them back, then you get more firewood and mulching materials, so where’s the problem?’ After three hours in Astrid’s garden, I had heard so many surprising nuggets like this that when I returned to my hostel, I spent an hour writing everything down before I forgot it.

Four months later, my trajectory sped up by the arrival of the pandemic. I was fortunate to find myself living in Coole Eco Community in County Offaly with ample space to practice agroforestry principles.

I had fun finding beneficial combinations of plants, informed by what I had read, what I had observed in the small systems I had created in the corners of community gardens in Dublin and what I had learned from Astrid.

At the end of my first growing season, acutely aware of how much I still had to learn, I set about interviewing various agroforestry practitioners around the country. I visited Suzie Cahn’s site and Hazel Nairn and Davi Leon’s farm, both in County Wicklow. I absorbed much valuable advice from these kind people.

Again, at Hazel and Davi’s, I was shown trees planted much closer together than the conventional standard would allow. This time, the trees were in agroforestry strips – a more organised version of a food forest, capable of being scaled up for commercial production.

I applied a lot of what I had learned to my own garden. Upon Suzie’s advice, I planted lots of mint on the forest garden floor to fill in any gaps in which grass might come up. I created an agroforestry strip, mimicking what I had seen in Hazel and Davi’s – long, narrow beds containing both fruit trees and vegetable crops.

As the fruit trees grow up, there will be less and less space for vegetables, but the vegetables provide ground cover and add valuable sugars to the soil, services that are especially needed while the trees are young. As Davi pointed out, in the wild, trees don’t come up in bare soil but through a carpet of green, forest floor vegetation. Annual vegetables can fill the roll that quick growing, annual forest floor plants fill in preparing the soil.

Towards the end of my second growing season, Coole Eco Community was fortunate enough to be offered funding from the Healthy Offaly initiative to run some workshops.

I jumped at the opportunity to invite Astrid to Coole to help us to improve our agroforestry systems while simultaneously sharing her knowledge with a group of people. Astrid had doubts about whether she had enough to teach or the ability to teach it. I knew these doubts were unfounded and she soon agreed enthusiastically to deliver two weekend workshops.

When she saw our forest garden and agroforestry strips, her first thoughts were ‘not enough trees’. I had tried to recreate what I had seen at her place and at Hazel and Davi’s but had still been too cautious about spacing. The mental block I had was very strong. I would think about planting things as close as they had done but something in me said ‘no, that couldn’t be right, I must have remembered it wrong.’

Astrid instructed us to plant at least 2 ‘feeder’ trees for every fruit or nut tree. Cherry, hawthorn and elder (wild fruit trees) were the best feeders for domesticated fruit trees such as apple and pear. Wild hazel, horse chestnut and oak were appropriate feeders for cultivated nut trees such as hazel, walnut and sweet chestnut. In addition to this, lots of willow cuttings were stuck in everywhere.

The one place I thought things were going wrong in the garden was the location Astrid was most happy with. There were wild cherries sprouting up close to apple trees and I had been worried about the apple trees having too much competition from them. Astrid looked at this and rejoiced, saying ‘this shows the wisdom nature has – it has created an agroforestry system without our help.’

Most of these feeder trees would not be let to grow to full size. They would be ‘chopped and dropped’ to feed the crop trees. They are vigorous trees that can mine nutrients from deeper down in the soil. They can share these nutrients with the hungrier and less vigorous fruit and nut trees in the form of the leaves they drop in autumn and the branches we cut off and apply as a mulch.

Basically, instead of bringing in compost and woodchips – work that can be backbreaking and expensive as well as having a carbon footprint – we are growing our own fertility and mulch right where it’s needed. As well as slow-release fertiliser, the mulch holds moisture in, prevents grass from growing and promotes the growth of beneficial fungi.

Some of the feeder trees will be allowed to grow to full height, especially the oak. With these, we will instead remove side branches to stop them encroaching on the crop trees. This way, the agroforestry system will have some height – more space for carbon storage, biodiversity and more beauty.

I had read and watched countless examples of chop-and-drop in action but always in warmer climates with very different, faster growing plants. There are no books or videos about how to adapt these methods in Irish conditions. UK research has been helpful but not extensive enough and still in a slightly different climate. It took the experiments of people like Astrid Adler and her years of experience to develop systems that are tried and tested in our cool, damp, dark climate. One key difference is that we need to plant more feeder trees because they grow slower.

We now have three 38-metre-long agroforestry strips set up, as well as a small forest garden adapted from an existing orchard. We will hopefully be harvesting apples, pears, raspberries, blackcurrants, gooseberries, rosehips and a mix of vegetables and herbs from these systems in 2022 as well as grazing chickens and growing commercial scale potatoes in the alleys between the strips.

In coming years, we look forward to harvesting cherries, hazelnuts, walnuts and sweet chestnuts – these trees are slower to produce.

We plan to continue to expand our agroforestry and to experiment with different systems, including those that can be integrated with grazing cattle. We hope to have Astrid back each year to mentor us and offer workshops to the public. I look forward to seeing the farm fill up with trees. As well as the countless benefits agroforestry provides to the environment, crops and livestock and to the farmer’s pocket, it is much more beautiful and interesting to be working amongst the trees than in a flat, windswept field. This reason alone would be enough for me.