Plants Used as Building Material

Numerous plants can be grown to provide us with building materials. There are a wealth of options, and identifying plants that we might grow on our own properties for a sustainable home and garden can help us to reshape the ways we live in profoundly positive ways.

Why Use Plants as Building Material?

Choosing natural materials to construct our homes, and to build useful structures in our gardens is a sustainable and eco-friendly choice. In certain instances, we may even be able to grow and source the materials we need on our own properties, to reduce the need to input any additional materials from elsewhere.

Construction with modern, intensively produced materials often comes at a huge cost in terms of emissions, energy use, water use and degradation of the natural environment. Using natural, plant-based materials in building allows us to reduce our negative impact, and can allow anything we build to sit more lightly on the land.

Plant Uses in Sustainable Construction

Numerous different plants can provide materials that can be used in sustainable construction projects, to make homes that function for us while also caring for our planet.

Plants used in construction can be those that are the primary building structure – creating the framework or walls of a building. They can be plants that provide fibres for use in composite natural materials to coat, render or plaster walls. They might be used to create a waterproof roof structure, or in a range of other ways within a building project.

Trees for Timber

One of the most important categories of plants used as building materials are of course trees that are used to produce timber for construction.

Timber can be a sustainable building material. Of course, how sustainable it is depends where the timber came from and the system from which it came.

Timber from truly sustainably managed systems can be a great building material, while timber taken from non-sustainable systems is of course a major problem – leading to deforestation and ecosystem degradation, as well as high emissions.

When we grow trees for our own construction projects, we can have full control over the system, and ensure that timber is not causing a reduction in tree cover. We can select native tree species and those suited to growth where we live, and minimise the carbon emissions associated with bringing timber for a project from far away. And we can carefully select the species we choose based on the needs and characteristics of our site and project.

Bamboo

Bamboo is another sustainable plant derived building material to consider. Bamboo can be used to form the structure of a home, or in creating many different elements within a home, from the walls, to the flooring, to fixtures and fittings...

Bamboo is a perennial plant that grows extremely quickly, and on marginal lands not always suited to other growth. It is strong, and resistant, while also being versatile and flexible.

Straw

Another important category of plant that can provide material for construction projects is straw. The dried stalks of cereal grains and other plants, straw can be used in construction in various different ways.

Straw can be used, baled, or compressed into straw blocks, to create straw bale homes, or as the infill for the walls of a timber framed building as insulation.

Straw can also be used to mix with clay and sand, or soil, for use in cob, wattle and daub, or adobe buildings. And can also be mixed with clay to create an internal clay plaster.

Straw is sometimes also used as a thatching plant (see below)

Thatching Plants

Straw is one of many plant-derived materials that can be used to make a thatched roof structure, and sometimes even walls. This is a traditional building technique that can use a range of different plants – often sedges, reeds, rushes or palm leaves, though many different plants are used for thatching around the world.

Used since pre-historic times, the technique fell out of favour in some areas, but there has been a resurgence of interest in thatching in some developed nations as interest in sustainable construction has grown.

Hemp

Hemp is one plant increasingly used in sustainable construction. It has a range of applications that make it of great interest to those interested in eco-friendly building materials. Best known as the plant that produces cannabis, Cannabis sativa is also prized as a fibre plant.

Today, it is used to make hempcrete (a more eco-friendly alternative to concrete), in hemp-lime construction and hemp-lime panels, for insulation within buildings, internal plasters, and more.

Other Plant Fibres

Other plants can also be used for their plant fibres within sustainable construction, both when it comes to basic building, and interior fit-out. They can potentially be used in ways similar to straws and hemp mentioned above, and also in ropes and lashings to secure elements of a structure.

Turf & Living Roofs

Turf construction is a traditional method that was used in some areas, where turfs of grass were laid upside down to form walls in areas where trees were scarce.

Today, turf roofs are becoming more popular, as people recognise the benefits that they can provide.

Increasingly, living plants as well as plant materials are being used in sustainable construction – most notably in the form of living roofs. Not only turf but also a range of other plants like sedums are being used to form these living roof structures.

Plants Used for Building in a Garden

As well as using plants as a building material for homes and other buildings, plants can also be used in a range of different building projects in a garden.

Exploring the different ways that we might use plants to construct garden features as well as buildings helps us understand how we can make full use of natural resources at our disposal, and cut consumption when it comes to creating and maintaining our outside spaces.

Living Plant Structures

The first thing to remember is that (as with living roofs) plants do not necessarily have to be harvested to be used in construction. They can potentially be used to build garden features while they are also in active growth.

Numerous trees and shrubs can be trained to form living fences, bed edging, arches, tunnels, arbours, play dens or gazebo-like structures in a garden.

One common example of this are willows, which can relatively easily be trained to form a number of different structures.

But many other trees, including useful fruit tree species, might also be trained into living structures in a garden.

Step-over apple trees, to name just one example, might be trained to form edging along the edge of a kitchen garden. And pleached or fan-trained trees might form barriers in place of fencing between one area of a garden and another.

Building Garden Features With Natural Wood

There are many different ways that you can use natural wood from your garden (coppiced or pruned material from trees and shrubs you grow) to create different things in your garden. For example, you might make:

• Fences in a range of different types, including log walls, picket fences, and wattle fences, with pliable natural branches woven in and out between upright stakes.
• Log retaining walls or structure for terracing on a sloping site.
• Pathways or rustic boardwalks
• Bed edging for raised beds, again, in a range of different styles.
• Material to fill and increase height in a raised bed (as in hugelkultur beds).
• Trellises and other support structures.
• Frames for growing tunnels/ row covers/ cloches.
• Benches or other seating.
• Children's play areas or dens.
• Garden artworks (for fun and aesthetic appeal).

Of course, these are just a few of the many things that you might be able to do with material from woody plants growing in your garden.

Building Garden Features With Bamboo

Bamboo can also be used to create a wide range of garden features. Again, as with woody branches of any kind, bamboo canes are of course also used for fences, pathways and boardwalks, bed edging, trellises and other support, frameworks for undercover growing spaces and kids' dens.

Hollow bamboo canes can also be used to create pipes for watering systems, or planting areas for a hydroponic system or aquaponic system in place of plastic pipes.

Smaller bamboo canes cut into short sections are also great for use within a 'bee hotel' or 'bug hotel' for your garden. Stacked together, they can help you create habitat for a wide range of wildlife species in your garden.

Building Garden Features With Straw

We spoke above about how the straw of various cereals and grasses can be used in baled or blocked form as a construction material, and also how straw is mixed with soils, sands and clays to make cob, daub or adobe.

Both straw bales as building blocks and also straw as a binding material in construction can also come in handy in a garden, just as much as in the construction of a home.

The same techniques that might be used on a full-sized building might also be used for a garden shed, summerhouse, chicken coop, greenhouse, or a range of other smaller structures in a garden.

Straw bales can also be used for bed edging, or even as the structure for a no dig bed itself. Straw bale gardening is a technique in which straw bales are topped with compost and planted up, serving as raised beds as the material slowly breaks down.

Straw can also be useful in a garden for its insulating properties, and might be used in the creation of hot composting systems, or in a hot bed filled with compost that gently warms plants from below as the material breaks down.

Uses for Natural Plant Fibres in a Garden

When building in a garden with plant derived materials like wood or bamboo, perhaps, you may also require something to hold structures together. And that is where a natural rope or garden twine may come in.

A number of garden grown plants can be used relatively easily to make a rustic twine for garden use. Personally, I use stinging nettles growing in my garden, harvested in summer, to make a twine that I have used for numerous different projects around my property.

Learning which plants can be used for plant fibres for rope/ twine or to use in other ways as a building material is one more great way to reduce garden costs, make your efforts more eco-friendly and sustainable, and avoid the consumption of damaging and harmful products (like a plastic twine, for example).

If you make your own twine/ binding material for garden structures, as well as selecting a natural primary material for your project, you can make sure that theentire thing is made from plants growing in your garden.

There are many inspiring projects that you might take on in your garden to make use of plants used as building material.

Often, the only limit to what can be achieved is your own imagination. Looking around your garden you will typically often find that you have more resources already available in your garden for your garden projects than you may have imagined.

By educating ourselves about the numerous uses of plants that grow in our areas, we can often make use of them in new and interesting ways, and create and maintain beautiful and productive gardens without relying on external inputs and making the most of existing resources.