Perennials

By perennials, I mean perennial herbaceous plants that do not have the appearance of being woody. The boundaries are fluid.

Often you will have one or more layers of plants below the shrub level in a forest garden. Perennials with many functions can also be used here. Many ground covers and mineral collectors also produce food. Fiber plants can be used in a hedge.

Design of the perennial layer in the forest garden

There are an enormous number of different varieties that can be used to cover the bottom layer of a forest garden. You can use a combination of herbaceous perennials that die down to the root every winter, evergreens, creeping perennials, bulbs, low shrubs and creeping shrubs. Naturally, you want fruit or vegetable perennials, but there are perennials with many other important functions.

You need plants (dead or alive) that cover the soil for as much of the year as possible. This protects against the soil becoming dehydrated and the rain digging up the soil. This is important to ensure that as many earthworms and other beneficial insects as possible maintain the soil. Plants in this layer can be mineral collectors. Plants with deep roots pull up minerals that other plants don't have access to, which they can access when the mineral collectors die.

Where light levels are not too low, nitrogen binders can also be used in this layer, enriching the soil for other plants.

Plants in this layer can be very attractive to beneficial insects, which are the mainstay of pest control in the forest garden. Several aromatic plants release high doses of aromatic oils during the growing season. One theory is that this improves the health of surrounding plants. The fact is that these oils are anti-bacterial and anti-fungal.

By having a thick plant cover over the soil, you have a relatively effective defense against weeds.

Less work

With perennials and perennial vegetables, you don't have to work with the soil every year. Turning the soil is very labor-intensive. When the soil is not turned/plowed, new weed seeds are not dug up and brought to life. Weeding therefore becomes less and less laborious over time.

Better for the soil

Soil structure is preserved when the soil is left undisturbed. This is beneficial for everything that grows in it. The amount of humus builds up, the nutrient content is not flushed out as quickly, and the soil is not as prone to drought while it drains heavy rainfall better. In a naturally developed system, it is mainly perennials that dominate the soil.

Longer harvest season

Short-lived crops are highly seasonal. In the Nordic climate, this usually means from late spring to early winter. Perennials can offer crops almost all year round, especially in early spring there is a wide range of perennials that provide edible crops.

More nutritious food

Most perennials contain more nutrients than annuals and short-lived vegetables. This is naturally because they have a better developed and larger root system. They utilize the soil more efficiently and therefore absorb more nutrients from the soil.