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Perennial Plants in Permaculture Systems

Perennial plants are plants that live over multiple years. These plants will not have to be resown or replaced each year but can survive in your garden for longer. Trees, shrubs and herbaceous perennials are great for carbon sequestration, and make up the heart of most sustainable growing systems.

Choosing the right plants is crucial within any permaculture system, and perennial plants are typically among the most important.

Many home-growers will focus in annual crop cultivation. But in permaculture, we can see the benefits that can be derived from including a large proportion of perennial plants within our landscape designs, and working with nature in holistic ways to achieve our personal and broader goals.

What are Perennial Plants?

If you are unfamiliar with the term, a perennial plant is simply one that has a lifecycle that continues over a number of years.

Unlike annuals, which grow and die in a single season, and biennials, which grow one year then produce seed and die the next, perennials are any plants that remain alive over several years – and often a lot longer.

Perennials include woody plants like trees and shrubs, and also a wide range of herbaceous perennials that don't have permanent woody frameworks above the ground. These often die back in winter in temperate climates before springing back to live the following spring.

Why Choose Perennial Plants?

There are many reasons why it is such a good idea to grow plenty of perennial plants on your property. We should grow perennial plants:

  • For a low-maintenance system.
  • For carbon sequestration.
  • For healthy soil and long-term fertility.
  • For wildlife-friendly spaces.
  • For natural abundance.

Let's dig a little deeper and look as these reasons to choose perennial plants in a little more depth.

For a Low-Maintenance System

From a human-centric point of view, perennial systems are great because once established, they typically take far less work to maintain.

First and foremost, when you plant perennials, you do not have to think about sowing seed or replanting each year. Perennial plants will remain to grow in a garden or other growing system for a number of years.

A well-designed perennial system such as a food forest or another largely perennial system is also easier to maintain because all the elements are carefully chosen to aid one another, and to contribute to the ecological function of the system as a whole.

With such systems, we can rely on nature to do a lot of the work, so as gardeners or farmers, our work is less intensive as a result. The symbiosis between plant species, and also the wildlife attracted by such a system, show us clearly that we humans are not the only gardeners at work. Wildlife attraction aids with pollination, and also with organic pest control, again lightening our workload on a farm or in a garden.

For Carbon Sequestration

Sustainable growing and food production means looking at how, within a site, we can not only meet our own immediate needs but also help in tackling broader, and even global issues.

Many of the world's problems can be solved in a garden and on farms adopting the right approaches can turn an enterprise into part of global solutions rather than part of global problems.

Mitigating our climate crisis involves significant emissions reductions. But it can also involve some key land-based solutions. Growing plenty of perennial plants can increase the potential for carbon sequestration on a tract of land.

Trees are of course crucial carbon sinks. Though planting trees is certainly not the be-all and end-all when it comes to tackling our climate crisis, carbon farming and carbon gardening can bring us closer to a solution and help us understand how effective and efficient use of land can help us limit Anthropocene global warming.

Trees, shrubs and herbaceous perennials, especially those with deep, woody roots, are all important in a design that maximises carbon sequestration in plants and within the soil. Layered perennial planting schemes, especially those that also meet human needs, are crucial for permanence within systems.

For Healthy Soil and Long-Term Fertility

Perennial planting can also help us to naturally ensure healthy soil and long-term fertility. The careful choice and placement of trees, shrubs and other perennial plants helps us to create ecologically functioning ecosystems that can stand the test of time and, crucially, are closed-loop systems which once established, require no external inputs from us to maintain.

A healthy perennial system is cyclical, with growth, decay, death and rebirth. Deciduous trees and shrubs drop their leaves, which decompose on the soil surface creating a rich humus in which both soil-life and plant life can thrive. Perennials can also often be chopped and dropped to feed the system over time.

With perennial plants in place, a living root is maintained in the soil at all times. Erosion and degradation of the soil ecosystem do not occur in such systems as often does in annual cultivation.

For Wildlife-Friendly Spaces

Perennial plants can also be essential in creating wildlife-friendly spaces, since plants that endure over a number of years provide habitat, shelter, food and more for many, many species.

While annual gardens or crop fields can attract some beneficial wildlife too, layered perennial systems are unrivalled when it comes to their rich biodiversity. And of course, this is something we should value in its own right, and not just for the benefits it confers to us.

For Natural Abundance

When it does come to benefits to us, perennial planting can also confer a more natural abundance. Perennial systems can be designed that can produce prodigious amounts of food, and other resources for human beings.

Fruit trees and nut trees, trees with edible leaves, fruiting shrubs, perennial vegetables, herbs and spices, edible flowers, seeds, roots and tubers... there are numerous yield-producing plants that can be included, depending on the climate and local conditions, within a perennial planting scheme.

The foods we can grow go far beyond the basics of potatoes, peas, beans, onions, carrots and cabbages, or tomatoes, peppers, squash and corn, for example, that many might be more used to growing as annuals on their farms or in their gardens.

Changes to what we eat and our food producing systems can help us create a fairer and greener world. Embracing edible perennials that grow in our areas is one great way to begin along that journey to a more sustainable and food-secure future.

Trees in Permaculture Systems

When many people think of perennials, they may not include trees and shrubs in this category. But these are technically perennial plants too – and are often particularly long-lived.

For Ecological Function and Long-Term Fertility

Trees are of course an important part of many permaculture systems and are often the first species established in a design. They are often keystone plant species and ecosystem engineers that shape the environment around them in a range of ways, often supporting a range of other plant and animal species.

Permaculture reforestation and afforestation can involve simply removing causes of deforestation and letting nature take the reigns. But it also often involves a holistic, design-based approach which involves mimicking the stages of the evolution of a naturally forming forest – while using human intervention to enable the process to continue, and in certain instances, to short-cut this process.

Pioneer tree species are crucial in establishment and in restoration of tree-based ecosystems. These trees are easily able to colonise land. These often include nitrogen-fixing species. These trees pave the way for future planting and increasing biodiversity on a site over time.

Native trees are often crucial to initial establishment of sustainable systems – carefully chosen species suited to the environment on a given site. These include those found in natural tree-based ecosystems within the same bioregion and specific area.

In permaculture, we often also mimic natural forests and woodland systems to create food producing spaces – forest gardens, or other agroforestry systems such as silvo-arable or silvo-pasture schemes. Productive trees, along with nitrogen-fixers, are typically the first plant type to be considered and planted within such systems.

Trees are also utilised in permaculture design for riparian systems, for wind-breaks or shelter belts, and for other specific environmental instances such as planting on steep slopes for soil stabilisation and to help with issues of runoff and erosion. Trees often drop their leaves to feed the soil within permaculture systems over time.

For Wildlife Benefit and Attraction

Native trees in particular are also often crucial in establishing strong biodiversity in wildlife within a permaculture design.

Trees such as oaks, for example, are known to support an astounding biodiversity in their branches, trunks and root systems.

And just five fruit trees in blossom can provide pollinators with as much nectar as an acre of meadow, as well as providing for wildlife with their fruits (or nuts, or leaves), as well as for us.

For Human Yields

Trees can also often be very important plants for yields within a permaculture system. Of course, there are fruit trees, nut trees and trees with edible leaves that can be abundant sources of food within a range of different climate zones and environments.

Trees can also provide a range of non-edible yields, giving us fuels, crafting materials, gums, resins, saps and many more resources.

Shrubs in Permaculture Systems

Shrubs are also perennial plants, enduring in place over a number of years.

For Ecological Function and Long-Term Fertility

Shrubs, like trees, can also be pioneers, and many useful and important nitrogen fixers fall into this plant category. Shrubs fill ecosystem niches below trees in the layered planting of a food forest, and can also be used in permaculture designs in other ways for ecological function and long-term fertility.

Shrubs might be used, like certain trees, for riparian planting, for planting on slope, and for wind-break planting – such as in a windbreak hedgerow.

For Wildlife Benefit and Attraction

Naturally, shrubs within a landscape or in a garden or farm design, as stand-alone species or in integrated forest garden or hedgerow systems, are also very important for the attraction of wildlife into the system. Providing shelter, cover and protection for many species, dense shrubs and hedgerows can be spaces for many species to hide.

Flowering shrubs draw in the pollinators too, and leaves of many shrubs provide food for animals in an area. And shrubs that produce berries or nuts are often feasts for native birds, mammals and other wildlife.

Selecting native shrub species can also be important in making a permaculture property as biodiverse as possible.

For Human Yields

Berry-producing shrubs, fruiting hedgerow plants, shrubs that produce nuts, and fruiting canes are all often crucial food producing plants with permaculture designs.

Shrubs can, like trees, also provide other non-edible yields such as wood for fuel or crafting, dyes, and other natural resources.

Herbaceous Perennials and Sub-Shrubs in Permaculture Systems

Non-woody perennial plants (herbaceous perennials) or plants with a minimal woody structure above the soil (sub-shrubs) can also live over a number of years. Some will live much longer than others, but all perennials within this category can be useful in several ways.

For Ecological Function and Long-Term Fertility

In a food forest design, these plants make up the layers below shrubs and trees. Usually these are grouped into taller herbaceous perennials and sub-shrubs, and groundcover plants when it comes to talking about the layers of a food forest.

But perennials of this kind can not only be included within a food forest design, but also in other planting schemes, such as edible and ornamental (edimental) beds and borders in a park or garden, or within dedicated perennial vegetable beds or perennial herb gardens, such as herb spirals, for example.

Like trees and shrubs, these perennial plants can also feed the system – either naturally dropping their leaves or dying back for a dormant period, or through our intervention in chopping and dropping organic material onto the soil as mulch.

This category of perennial plants also includes nitrogen-fixing species, and dynamic accumulators, often deep rooted, that are particularly good at gathering and storing certain nutrients.

Deep rooted perennials can be particularly useful for carbon sequestration as well as for gathering nutrients from deeper layers of the soil. They can also help to stabilize soil, reduce compaction and prevent erosion.

Ground-cover perennials help us further in preventing runoff and erosion. They keep bare soil covered, and a living root in the soil, reduce moisture loss from the soil and suppress weed growth to a degree.

Spring bulbs are a specific perennial that can suppress the ingress of grass or weeds into tree guilds or forest garden planting areas. These spring ephemerals also catch and store water and nutrients early in the year, and provide a nectar source for pollinators early in the year.

For Wildlife Benefit and Attraction

Numerous flowering plants within this category of perennial plants obviously attract pollinators, and insects beneficial in pest control in an organic growing system. The huge diversity within these layers of planting on a farm or in a garden provide habitat and resources for many species throughout the year.

For Human Yields

Fruit and nut trees and berry bushes are of course very familiar perennial food sources for most. But other non-woody perennial food sources are often much less well known.

Many will also be familiar with the many perennial herbs that can be grown for culinary or medicinal use, or for other uses. And most will also be familiar with perennials like strawberries and rhubarb, and perennial vegetables like asparagus and artichokes perhaps.

But there are a huge list of perennial herbs,vegetables and edible flowers that might be considered for inclusion in permaculture planting schemes, and embracing perennial edibles native to or suitable for growth in your area is a wonderful way to grow your own in a lower-maintenance and more sustainable way.