Introduction to Firescaping in Zones

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Image by Matthias Fischer from PixabayImage by Matthias Fischer from PixabayDid you know that Africa is known as “the fire continent” as more of Africa burns each year than any other continent on Earth? Being “fire-wise” should therefore be a priority, and is vital to protect your home and suburb against wildfires. In this article you will learn how to easily implement precautionary steps which will drastically reduce the threat that wildfires pose to your family and your home. Read more below about firescaping your garden.

If you select the correct plants, you can still create a beautiful, but more importantly, fire resistant garden. Keep posted, as I will soon be publishing lists of suitable groundcovers, shrubs and trees recommended for firescaping.

South African’s are well aware of the threat of wildfires, which often result in considerable financial loss and even human fatalities. In September 2023 it was reported that due to the recent wildfires in many parts of South Africa, at least 1.2 million hectares of land was affected by ongoing fires in the provinces, with the Free State, North West and Limpopo being among the hardest hit. Nearly 200 animals had to be euthanized in the aftermath, and it was estimated that farmers lost at least 1 billion Rand’s worth in crops and livestock during August and September. 

The 2021 Table Mountain fire, also known as the Rhodes Memorial fire was a major fire that started in and around Table Mountain National Park, and the neighbourhoods of Newlands, Rosebank, Mowbray and Rondebosch. It was reportedly started by a vagrant and quickly spread through old pine trees and debris, generating its own wind while spreading towards the university campus and city. Students at the University of Cape Town were evacuated and official warnings were issued for hikers in the Newlands Forest area of Table Mountain National Park to also evacuate. The blaze destroyed the restaurant at Rhodes Memorial, and the M3 road was also closed, due to the fire jumping the road and spreading to the other side.

Wildfires swept through many parts of the Garden Route in June of 2017, and Knysna and its surrounding areas were absolutely devastated, with thousands of people having to be evacuated. The aftermath revealed that over 1,000 structures were totally destroyed, 500 houses were damaged, and because critical infrastructure like power lines were either damaged or destroyed, local businesses were unable to operate. In 2018, it is estimated that the George/Outeniqua fire destroyed 90,000 hectares, an area four times the size of the 2017 Knysna fires which saw 22,000 hectares razed.

Fire is one of the oldest issues in the ecology of Africa’s vegetation, and in the days before human populations reached their present high levels, fires were started mainly by lightning. However, today most fires are started by humans, either accidentally or deliberately. Something as simple as a negligent driver throwing the butt of a cigarette on the side of the road can result in a wildfire.

Aspects of the vital role natural wildfires play in our ecosystems remains contentious, and its use in ecosystem management also continues to be debated. Ecologists understand that fires are a natural and integral part of the ecology of most African ecosystems, and that many plant species are ‘fire-dependent’, relying on fires to complete their life cycles, and would become extinct without them.

Many plants in fire-prone areas are able to sprout after fire, either from below-ground roots or bulbs, or from epicormic buds which lie dormant and are protected underneath thick bark. Some plants like Proteas hold their annual production of seeds in ‘fire-proof’ flowers, and when the plants are killed in fires, the seeds are released and germinate when the next rains arrive.

For such species fires are essential, and without fire the seeds cannot germinate, as the seeds are stimulated to germinate by the chemical cocktails contained in smoke. Some plants may have even evolved properties that make them more prone to burning by producing lots of dead material, and highly flammable oil content in their leaves.

Africa has the largest area of savannas in the world, and 6 to 8 million years ago, fire due to lightning strikes was a significant factor determining the evolution of these grasslands, because fire promotes the growth of grasses, and also prevents the development of dense woodlands and forests. In savannas, the balance between grasses and trees is maintained by fire, and it has been clearly demonstrated that the exclusion of fires for long periods leads to the elimination of grasses and an increasing dominance of trees and shrubs. In simple terms - without fire our African ecosystems would look totally different.

In South Africa fires are a natural feature of many of our ecosystems, and in the dry season they occur regularly in fynbos shrub-lands, grasslands, and savannas across the country. Such vegetation does not normally burn in the wet season when the plants are green, but in the dry season all that is needed is a source of ignition for devastating fires to occur. Lightning provides ample sources of ignition, as do humans, so frequent veld fires are inevitable.

Now more than ever, South Africans need to build a culture of fire-wise communities. ‘Building Fire-Wise Communities’ is a concept originally developed in the United States, and has since been adapted and implemented in South Africa. The Fire-Wise approach is not a solo mission for home owners, but rather emphasises the responsibility communities have in designing a safe community. It also promotes effective emergency responses to fires, and emphasises the responsibility individual home owners have regarding safer home construction and design, as well as fire-wise landscaping and maintenance.

People that live where fires are a real danger can do many things to protect their property, and although firescaping won't guarantee the safety of your property, it will certainly decrease the risk.

Firescaping involves landscaping in ways that will reduce the probability of a fire catching and spreading through an area. It is vital to have a survivable space around your infrastructure, and creating this safe space involves modifying your property’s layout, hard landscaping materials and plantings, to reduce the risk of your home catching alight during a wildfire.

Fires always happen when three necessary elements come together: sufficient fuel of the right kind; warm, dry weather, and a source of ignition.

The first step is to assess the vulnerability of your property, as well as that of your neighbours. If it is close to a forest or thickets of vegetation, it is at risk, and if it is sited at the top of a hill, or where it is subjected to strong winds, this will make it even more vulnerable. The amount of fuel, the strength and direction of the wind, and the lie of the land, make a huge difference to the intensity of fire, and what it burns. On the whole, the steeper the slope the faster a fire moves so houses on steeper land need wider buffer zones.

Even if you were to remove all vegetation from around your property and pave or plant lawn in the entire area, your home could still catch fire from burning embers carried on the wind. A windbreak of trees or a belt of green vegetation that is not highly flammable is more effective at stopping or slowing down a fire.

A simple test to gauge the fire vulnerability of the trees and shrubs in your garden is to build a small fire and throw a small sample of both green and dried foliage from each tree and shrub into the fire to see how much it flares up. Consider removing plants with foliage which flares fiercely.

In areas prone to wildfires you should never use flammable materials in the garden like wooden fencing and trellising. Steel trellising and brick and stone walls are better as they help slow down a fire. Also, never apply organic mulches like bark chips unless they can be kept moist, as dry mulch is a fire hazard. Rather use gravel, pebbles, concrete pavers, and succulent groundcovers.

Make sure that you have access to water to put out spot fires or wet your roof. Keep gutters free of debris, and install a sprinkler system that will saturate your roof, house and garden if a fire threatens your property, and check it regularly to ensure that it works properly. If you can, also link your sprinkler system to an alternative water source like a swimming pool or large water tank, and purchase a strong diesel pump to ensure you will be covered should the electricity be off at that critical time or the municipal water pressure is too low.

A fire-fighting vehicle has to have easy access to your property and home to effectively fight a fire, so keep certain pathways or stretches of lawn open and free of anything that could block access to driveways, gates, or pathways.

Should the power go down, have some means of communicating with each other in the community, and if you have a battery operated radio you can monitor the news. Keep a fire-fighting kit on hand, and if a fire does close in, shut all windows and doors, and if you have to escape, do so shielding yourself with a wet blanket.

Garden in zones

There is no such thing as a fire proof plant, but there are ‘fire retardant’ and ‘fire resistant’ plants, and with the ‘Building Fire-Wise Communities’ concept developed in the United States, they recommend dividing the garden into planting zones. This planting method is designed to slow down a fire, and most importantly to create a safe zone around your home. And it’s really quite simple!

The garden is divided into three planting zones:

A fire resistant “Buffer Zone” on the perimeter of the property.

The “Garden or Medium-Resistance Zone”.

A 3m wide “Low Resistance Zone” which is closest to the home.

The perimeter or buffer zone

The first but most important step in firescaping your garden is to create a fire resistant buffer zone on the perimeter of your property, because this is the furthest away from the home, and your first line of defence. If your property borders a forest or thickets of vegetation, is sited at the top of a hill, or is subjected to strong winds, do regular inspections of the perimeter and remove all dead or dying plant material which could fuel a fire. If this space encroaches into your neighbours’ properties, then it makes sense to work together to create a joint survivable space and hazard reduction plan.

Cut down or spray all alien, invasive plants, including Australian Acacias like Blackwood’s, Port Jackson and Rooikrans; as well as Pines, Cypresses and Eucalyptus/Gum Trees, which contain high levels of resin or oils in their leaves and will just explode into flames in a fire.

Click on highlighted text to see Google Images of the plants mentioned.

Our indigenous thorn trees (Vachellia, previously called Acacias) ooze thick sap that dries in globs, making them highly flammable and also likely to explode in a fire. Most plants with fine or small, thin leaves, also often accumulate lots of dead leaves or wood inside the plant which will catch alight quite easily, so remove Australian Bottlebrushes, Melaleucas and Conifers, and especially those growing in the buffer zone, as these plants burn even hotter and fiercer than our indigenous fynbos, which also catches alight quite easily, especially after weeks and weeks of no rain and drying winds.

For large properties or farms, fire breaks are made by utilising sand or gravel roads, or by conventional burning of breaks. If you live in the city or suburbs your buffer zone will be determined by the size of your property, but to be effective should be at least 5m away from the house.

On large properties fire buffer zones are sometimes cleared and planted with sweeping lawns and sprinkler systems, but in our hot and dry climate, during times of drought when large expanses of lawn cannot be watered, this could turn into a fire hazard. Therefore, although there is really no such thing as a totally fire resistant plant, many people opt to plant them exclusively on the perimeters of their property.

There are some core reasons why you should plant fire retardant trees around our home to make it safer.  A windbreak of trees gives protection for a distance of roughly twenty five times the height of the trees, and trees have the added benefit of slowing the wind and catching embers. Fire retardant trees are also a physical barrier to the heat blast coming through, acting as a green shield in front of your home, and some trees will actually stop the fire from moving through because the amount of moisture in the leaf tissue of the plant is enough to stop the fire.

For example, a row of our indigenous Milkwood trees (Sideroxylon inerme) with their thick, leathery, evergreen leaves, and dense, low crown, can stop a fire dead in its tracks, and people with homes situated on mountains where fires frequently occur, are recommended to plant a row as both a fire and windbreak in the buffer zone.

Members can click here to read more about Sideroxylon inerme

A great plant for smaller properties is the Sand Olive, and studies done by the Commonwealth Scientific and Industrial Research Organisation (CSIRO), who tested and listed the ignitability of Australian plants, listed the Sand Olive, (Dodonea) on List 1, as ‘plants backed by scientific evidence for overwhelming use as a fire break’. 

Members can click here to read more about the Sand Olive

Unless you are planting a hedge or windbreak, its best to keep the buffer zone more open. Fire-resistant trees must be widely spaced so that regular maintenance can easily be carried out, and to ensure easy access in the event of a fire. As the trees grow, trim up the lower branches to reduce flammable material close to the ground, and don’t plant shrubs close their stems as these can create a ‘fire-ladder’ effect. Remove dead leaf litter under and around trees and hedges regularly.

If you plant a hedge, try to use plants that will re-sprout after a fire, and which do not accumulate a large quantity of dead material inside the plant. For this reason, Proteas would not be a good hedging or screening plant for the buffer zone.

Good hedging or screening plants for the perimeter buffer zone, which will re-sprout if burnt and appear on various firescaping lists, include our indigenous Karee trees: Rooikaree, Mosilabele (Searsia lancea); Glossy Currant, Blinktaaibos, inHlokoshiyane (Searsia lucida);  White Karee, Witkaree, mosilabele, Garas (Searsia pendulina); and (Searsia chirindensis). These trees are also useful soil stabilisers, and increase the soil penetration of rainwater, reducing erosion and raising the ground water table.

Members can click here to read more about Searsia lancea

Members can click here to read more about Searsia lucida

Members can click here to read more about Searsia pendulina

Members can click here to read more about Searsia chirindensis

If you don't have space for a windbreak of trees, a belt of suitable, evergreen, low-growing vegetation will also offer protection. Many of the plants used in this zone are succulent and do not need copious amounts of water, but to keep them at their fire-resistant peak, try to water during long dry spells.

A selection of succulent groundcovers and other fleshy-leaved groundcovers will temper down a fire by catching the embers from advancing flames. There are many indigenous succulents you could use like:  Ice Plant (Delosperma): Hottentots Fig, Kaapsevy (Carpobrotus); Tree Houseleek (Aeonium); and Rock Rose (Echeveria elegans), and although they can be used in any of the garden zones, they are especially good for the buffer zone as these drought tolerant plants are also used as part of xeriscaping – a landscaping method that reduces or eliminates the need for supplemental water from irrigation.

Members can click here to read more about Carpobrotus

Members can click here to read more about Delosperma

Members can click here to read more about Aeonium

Members can click here to read more about Echeveria

Many exotic garden plants are also known to be fire resistant, and Common yarrow is highly rated in numerous firescaping plant lists  as having low ignitability, and is used as a fire barrier, created by replacing highly flammable vegetation with species that are less likely to burn and which can help prevent ignition or slow down the spread of the fire.

Members can click here to read more about Achillea

The Commonwealth Scientific and Industrial Research Organisation (CSIRO) tested and listed the ignitability of Australian plants, and they listed Fairy Fan-flower (Scaevola aemula) on List 2, as Australian plants that regularly appear on many lists as fire retardant plants. This prostrate and spreading little evergreen makes a wonderful groundcover and edging plant for all types of gardens.

Members can click here to read more about Scaevola

Planting a selection of evergreen shrubs like aloes for their fleshy, moisture-retaining leaves, will slow down a fire. The African Aloe, Soap Aloe, Bontaalwyn (Aloe maculata) is an excellent fire-retardant succulent for areas prone to wild fires, and because it spreads via suckers is a good choice for a groundcover in the buffer zone. The Spekboom, isiDondwane (Portulacaria afra) is also highly recommended for firescaping. The taller forms make a wonderful hedge or windbreak, and the dwarf forms make excellent groundcovers or low growing shrubs or hedges.

Members can click here to read more about Aloe maculata

Members can click here to read more about the Spekboom

Planting a belt of these fire resistant plants in the buffer zone, at least 50cm but preferably 1m or more wide, should stop or at least drastically slow down most grass fires. Another plus is that because they are drought resistant, they are useful to use for holiday houses that are left unattended and un-watered for long periods.

Even if your property hasn’t experienced a fire yet it advisable to use small plants that will re-sprout after a fire in the buffer zone. And when it comes to fire breaks, Agapanthus remains one of the most popular plants, as their foliage slows down a fire, and their underground roots and tubers survive fires and help prevent the soil from being blown or washed away when there is little other vegetation around after a fire. And as soon as the rains return they will re-sprout. In Australia, farmers have used Agapanthus as fire breaks for over one hundred years, and they have proved their resilience, sparing many farms and homes from wildfires. Wild Garlic (Tulbaghia) is also highly recommended for the buffer zone.

Members can click here to read more about Agapanthus 

Members can click here to read more about Tulbaghia

If space allows it is most beneficial to leave and ‘island bed’ between the buffer zone and the garden or medium resistance zone. This part is often a stretch of lawn but could also be a gravel or flagstone pathway. This free-standing strip in the garden acts as a mini firebreak between the buffer zone and the garden zone.

The garden or medium resistance zone

The garden or medium resistance zone lies between the buffer zone and the inner band, or low resistance zone closest to the home. It is possible to plant a garden here using fire-resistant trees, tall and short shrubs, and groundcovers. The trick is to space your bigger plants more widely apart so that they don’t touch once the plant has matured, as this prevents a dense thicket of shrubbery that could support a very hot fire.

Only non-flammable hard-landscaping materials should be used, like flagstone walkways, brick patios, stone retaining walls, gravel and other inorganic mulches.  Avoid timber decking, wooden pergolas and archways, and organic mulches like bark chips.

In this zone more shrubs and trees with fleshy, moisture-retaining leaves are used, and if space permits, these are also planted in ‘islands beds’ which are surrounded by lawn or non-flammable pathways. These ‘island beds’ will slow down the fire further and help to shield your home from the intense heat that can shatter windows. Ideally, island beds should be three to five meters apart.

Although Fynbos species can burn fiercely, they can be used in this zone if they are planted in ‘island beds’, but remember to space tall and short shrubs in a way that, once the plants are mature, they will not form a dense thicket of foliage which can provide fuel for a very hot fire.

In the garden, or medium resistance zone trees are usually planted individually in ‘island beds’ and shrubs are not planted close to the trunks, as these can act as ‘fire-ladders’, helping flames climb from the ground up into the canopy. Remove the lower branches of trees up to about shoulder height, or twice the height of surrounding vegetation, and to prevent flames from spreading along the ground, always keep the areas under trees and shrubs clear of all dead and decaying wood, fallen and dead branches, and large clumps of dry grasses.

The low resistance zone

This zone is closest to the home and should ideally be a 3m belt around the house. Excessive vegetation adds fuel to a flame, so the plants nearest your home should be widely spaced and low-growing. Avoid large masses. Instead, plant in small clusters using a wide variety of species.

Keep this area free from dry plant litter, and trees or large shrubs that are flammable, and especially those with branches that touch or overhang your home. Trees, climbers, and medium or large shrubs planted directly up against buildings can act as ‘ladders’ for a fire. If you simply must grow climbers on the house, make sure they are supported by metal trellises or pergolas, and clean out any dead twigs and leaves regularly.

Only non-flammable hard-landscaping materials should be used, like flagstone walkways, brick patios, stone retaining walls, gravel and other inorganic mulches.  Avoid timber decking, wooden pergolas and archways, and organic mulches. However, if you already have, or want wooden decking, use fire-resistant wood or wood treated with a fire retardant for decking, and keep the areas underneath clear of vegetation. It is also important to remove debris regularly from gutters, and to keep your garden free of dead plant material.

This zone of the garden closest to the home should consist of well-irrigated, fire resistant small shrubs and low-growing ground-covers, and if you have a lawn, try to keep it well-watered, and mow regularly to prevent a build of dry grass called “thatch”.

There are many popular garden plants that are suitable for planting in this zone, like roses and flowering perennials, herb and vegetables.

Try to water this garden zone regularly during the dry season to keep the moisture content of the plants high. Make sure that you have access to water to put out spot fires or wet your roof. Keep gutters free of debris, and install a sprinkler system that will saturate your roof, house and garden if a fire threatens your property.

Most importantly, remember that a fire-fighting vehicle has to have easy access to your property and home to effectively fight a fire, so keep certain pathways or stretches of lawn open and free of anything that could block access to driveways, gates, or pathways.

Although a lot of research has been done on the fire resistance of many garden plants, the science of firescaping is still in its infancy and a lot of studies still need to be done on this subject. There are thousands of fire resistant plant lists available online, some of which are compiled simply by observing which garden plants have survived fierce wildfires, and which seemed to fuel the fires.

The plants mentioned in this article come from information available in South Africa, and worldwide, but especially from fire prone regions of Australia and California, as they grow many of the same garden plants as we do in South Africa.

The purpose of this article is to provide homeowners with guidance on ways to landscape their property with fire resistant plants to help reduce losses from wildfire damage. It contains suggestions and recommendations, and is intended to serve only as a guide. If you live in a high fire zone it is recommended that you do your own research and seek advice from garden centres and locals in your area before making your final decision.

Keep posted, as I will soon be publishing lists of suitable groundcovers, shrubs and trees recommended for firescaping.