There is a kindergarten in Tauranga, New Zealand, that really cares about the health of it’s children. They are keen on putting in a self-regulating food forest or forest garden, that will provide a variety of nutrient-dense and organically grown, fruit, nuts, berries, vegetables and herbs all year round, without the high maintenance and inputs of a conventional orchard.
A ‘food forest’ is exactly like the name implies – a forest of food, and it should mimic a natural forest which has various ‘layers’ and is self-regulating, but the difference being, most of the plants within the food forest produce food or useful materials for us!
A key component of creating a food forest or forest garden, is to include all seven layers of a natural forest ecosystem.
- ‘Canopy layer’ consisting of the original mature fruit trees.
- ‘Low-tree layer’ of smaller nut and fruit trees on dwarfing root stocks.
- ‘Shrub layer’ of fruit bushes such as currants and berries.
- ‘Herbaceous layer’ of perennial vegetables and herbs.
- ‘Rhizosphere’ or ‘underground’ dimension of plants grown for their roots and tubers.
- ‘Ground cover layer’ of edible plants that spread horizontally.
- ‘Vertical layer’ of vines and climbers.
Generally they are perennial plants, and by including all layers there is less opportunity for undesirable ‘weeds’ to get established. We must include maximum diversity and maximum interconnections. Each plant plays a different function within the food forest, and supports the other plants whether it is through providing shade, providing mulch through leaf drop, breaking up compacted soil with a deep tap-root, ‘mining’ minerals from deeper in the soil or fixing nitrogen from the air and making it available to other plants. One thing is for sure – it is a regenerative, soil fertility building system.
Kay Baxter from the Koanga Institute, New Zealand’s Permaculture Research Institute recently held a workshop around the country – “Design Your Own Forest Garden”. The workshop was based around an amazing little booklet by the same name that draws on Kay’s extensive gardening experience, and information relevant to New Zealand’s climate, gleaned from various forest garden textbooks.
Through a series of charts and tables, the booklet takes you through a step-by-step process of how to design your backyard forest garden and can be summarised by:
- Measure and analyse the area for wet and dry spots, cold and prevailing winds, sun path, soil pH etc
- Choose no more than 50% of the total forest garden area to be taken up by the mature fruit tree canopy. Select the fruit trees you want taking into account canopy size, fruiting times (to get fruit all year round), rootstock for the right soil conditions, and climatic factors such as wind and sun.
- The fruit trees need nitrogen to grow bigger, so nitrogen fixing legume trees are planted around each fruit tree. For heavy feeding fruit trees such as citrus and apples, 80% of their total canopy area needs to be planted as the canopy area of nitrogen fixing trees such as tree lucerne or tagasaste (Chamaecytisus palmensis).
- To supply the potassium needs of each fruit tree, 1 comfrey plant should be planted for every square metre of canopy area. For example, a 30m2 peach tree should have 30 comfrey plants around the north-facing dripline. As well as supplying the tree’s potassium needs, the comfrey makes an impenetrable border to invasive grasses.
- The rest of the space should be filled with ground covers, small shrubs, and vines of the specific guilds to make up the seven layers. Guilds are a group of plants, animals, insects and fungi that have co-evolved together in the same regions and climates, and act like companions.
In New Zealand we can divide our main fruit and nut trees into the following guilds:
- Temperate Guild
- Mediterrannean Guild
- Citrus/ Loquat Guild
- Feijoa Guild
- Subtropical Guild
Each of these guilds are suited to a certain set of climatic and soil conditions, and when choosing plants for each guild a good guide is to choose the conditions the plants like best and group these plants together, whilst trying to fill each layer and role in the food forest.
The Koanga institute have created a database of suitable forest garden plants for New Zealand- an amazing resource for those of us wanting to design a forest garden. It is constantly evolving and can be downloaded here as a spreadsheet file:-
We have designed the Kindergarten food forest using this method and permaculture principles, and will be blogging about the design and the rationale behind it in our next blog post, “Kindergarten Food Forest Design Part 2. The Design”.