Coppicing Hazels: Insights from Nine Hazels Farm

Sanna & Paul Mairet of Nine Hazels Farm

Climate Land Leaders Paul and Sanna Mairet of Nine Hazels Farm grow 12 acres of hybrid hazelnut, a cross between the European hazelnut and the native American species. As a perennial crop, hazelnuts have an extensive root system, which increases water infiltration, soil organic matter and carbon sequestration – and the shrubs provide shelter and nutrition for wildlife. Humans also enjoy the nuts and oil and have a long tradition of creating functional and artistic forms with the wood.

Paul with “a mess of sticks” AKA coppiced hazel

With support from a Minnesota Department of Agriculture Sustainable Agriculture Demonstration Grant, Paul and Sanna are researching coppicing – cutting back the shrub to promote new growth – and the market for the wood harvested in the process.

Says Paul: “According to a limited amount of research, old hazels that aren’t producing many nuts should regrow and resume peak nut production within three years of coppicing. In Europe especially, hazels are coppiced as often as every 7 years because they are focused on harvesting the wood for crafts. We’re working to see if hybrid hazels can be used similarly to European hazel, rejuvenating our grove and creating sustainable crafts through that process.”

Paul shared some successes and challenges from the 2023 season. Here’s his account:

It will be a few years before we see the extent to which coppicing improves hazelnut yields, but the vigorous regrowth (nearly 5 feet in one season!) shows that this practice is beneficial on some level. On average, about half of the stems we removed were dead. These stems were broken up and left to decompose around the base of the plant. The live rods were measured, compared to UK standards for crafting with European hazel, and used to make crafts.

This practice also benefits the ecosystem as a whole. As the hazel canopy is removed and returns over several seasons, this results in varying space and light in the area around the plant, which allows a wider diversity of plants to accompany the hazel. The wider diversity of plants encourages biodiversity in fauna as well. This diversity includes other perennials. To improve the overall genetics present in our hazel grove’s pollen, we could remove hazels that produce smaller and fewer nuts. We were initially wary of the idea of removing perennials from the ecosystem, but if they can naturally be replaced by a diversity of other beneficial perennials, that accomplishes two goals in one activity!

As an example, see the photo with the regrowing hazel with echinacea taking advantage of light access at the base and a young slippery elm waiting to be the main tree in the space if the hazel proves to be a lower performer in terms of nut production. Maybe all of the plants can get along, too – a naturally forming guild of edible and medicinal plants!

First shoots resprouting from a coppiced hazel

Coppiced hazel resprouts a little further along

Fuller hazel regrowth in late August with echinacea at the base and slippery elm to the left

The main challenge is the time it takes to accomplish this work! We devote significant time to coppicing and invasive species removal. On average, it’s taking me about 20 minutes to coppice a hazel. I am doing this carefully by hand with loppers to ensure healthy stools and avoid fossil fuel consumption. Colleagues have reported that you can run a forestry mulcher over hazels and they will regrow. For invasives, we ideally want to remove them without the use of herbicides. I am also cutting them with loppers but leaving a foot or so of stem, so that I can easily keep track of them and remove the new growth when they inevitably resprout. Time will tell us if this is effective or if we will have to change our strategy to keep buckthorn, wild grape, siberian elm, white mulberry, and more at bay.

Another challenge is that some of these invasive plants have beneficial properties: the only trees large enough to provide shade in our future chicken habitat and current vegetable/herb garden are siberian elm trees that the previous owner allowed to mature. The white mulberry trees have edible berries and rot resistant wood that could make for good fence posts. We are working to plant other shade trees, but it will be many years before they grow big enough to provide meaningful shade. We will also experiment with coppicing the mulberry and see how many years it takes to produce berries again. It might be possible to harvest it for its useful wood regularly enough to keep it from spreading via bird transported berries.

Hazel coppice in the center with dead branches on the right, ~2 foot tall buckthorn stem to the left, and a tiny (hard to spot!) conifer left of the buckthorn that we might allow to fill the space if the hazel later appears to be a lower performer in terms of nut production

Close-up of the tiny conifer (we have mature white pine, jack pine, and white spruce nearby)

Bumblebee enjoying wildflower pollen deep in the hazel grove. You can imagine how these flowers will explode when we coppice this hazel and let the sun in!