Plant List: Understory Plants for Temperate Climate Edible Forest Gardens
Edible forest gardens are designed around layers. This includes canopies, shrub layers, herbaceous perennials and ground covers. Often the lower levels are not easily distinguishable, so we group the herbaceous perennials and ground covers into the one group of understory plants. Generally, the understory includes plants that grow to a maximum height of less than one metre. This understory layer may consist of one strongly growing herbaceous perennial layer, but more often it will be two or three layers of vegetation. Often it is the amount of light filtering down to the ground level that determines the density of vegetation growing there. As the understory layer can be subjected to heavy shade, many of the ground cover species are selected for their shade tolerance.
Plants in the understory ideally perform more than one function, and may be beneficial for medicinal uses, nitrogen fixation, mineral accumulation, beneficial insect attraction, repelling or confusing pest insects, wildlife habitat, protecting the soil, as a living mulch to out compete and suppress weeds, or to retain soil moisture. They can often be aesthetic and sometimes (but not always) edible!
Edible forest gardens are constantly evolving. As the canopy trees grow, the microclimate and soil conditions change. The biggest change is the shade and sunlight received at ground level. Due to the complexity of these changes, it can be very difficult to design the understory layer with high levels of predictable outcomes. Instead the focus when designing the understory plants should be on increasing species and variety diversity to increase the resilience of the ecosystem. Nature will then take the pallet of plants included in the ecosystem and in time will find its own balance. Included here is a list of understory plants that I often include in edible forest gardens.