The shrub layer in a forest garden is one that is sometimes neglected in design. Those new to forest gardening often focus on the trees, then their attention leaps to the herbaceous layer. If they do think about the shrub layer at all, initially, people’s minds tend to leap to typical fruit bushes like gooseberries and currants.
But the shrub layer in a forest garden has more to do than just provide berries. Do not underestimate the important role that shrubs can play in a forest garden or woodland garden system.
One function that they fulfil in my climate is as nitrogen fixers. Here, there are a few trees – alder, laburnum… that fix nitrogen. (And I do have a laburnum in a different part of the garden.) But in a smaller forest garden like mine, the deciduous nitrogen fixing shrubs like Elaeagnus are crucial.
Beyond nitrogen fixation, shrubs also provide a range of other yields and services. Shrubs around the edges of my walled forest garden are well-used by birds, for nesting and shelter. Small mammals also hide out in the shade and shelter they provide. These dense and vegetated spaces between the canopy and the herbaceous layer are great for wildlife.
Shrubs shelter and shade other plants too. Commonly used in wind break hedgerows, they can also benefit lower tier forest garden plants with the microclimates they create. Not only can they create areas of deeper shade, they can also create warmer and more humid areas that might benefit plants growing nearby.
Remember, shrubs are also sequestering carbon – just like the trees. As long-lived woody perennials, they can often play an important role in combatting climate change in your garden.
If you would like some help to create a forest garden where you live, please do get in touch to discuss your requirements.