How to firescape your garden

LIFESTYLE NEWS - Fire has become the new norm, not only in our part of the world but also globally.

Due to global warming we can expect drier, hotter summers and winters with less than average rainfall.

In Knysna, many properties were destroyed in 2017, possibly because the vegetation around the homes was dense and high, acting as perfect receptacles for flying embers.

Alien invasive species, some plants such as palms, bottlebrush, conifers, pines and highly combustible fynbos species all contributed to the destruction of neighbourhoods.

Living in areas which are fire prone should influence homeowners and garden designers to look afresh at plant choice and garden layout.

Property owners should reassess the landscape around their properties, how to create barriers in order to ward off wildfires, and how to embrace "zone" planting. Research has shown that 90% of the time, homes are destroyed by ignited embers and not by a wall of flames: we need to rethink the traditional "foundation planting" of trees and shrubs up against a house, designed to blend structures with nature for maximum curb appeal.

Defensible spaces

Pathways
The practical aspect of fire-safe landscaping should include meadows and defensible spaces. The idea is to create an airy, open "defensible" space around your home and plant nothing that touches the structure or looms above it.

Surround your house with walkways or paths, keep them clean of dried leaves, and plant drifts of fire retardant plants. Although lawns are water guzzlers and require high maintenance, they should not be ruled out completely as they create a perfect barrier.

Any garden needs trees, but they should not be planted closer than 3.5m from structures, and preferably not in groups as they create "fire ladders" that help flames spread from one plant to another.

Trees with high resin or oil content such as conifers, pines, eucalyptus, bottlebrush, and citrus should really be avoided; also palms as their fibrous bark and shaggy dead fronds ignite easily, creating fierce fires and showers of flying embers. Vines framing your entrance and other highly combustible vegetation near your home also serve as easy fuel for wind-borne embers.

Succulent garden
Whether or not a plant will catch alight, keep a fire going or propel a fire is determined by its physical characteristics. Fire-retardant plants are directly related to the amount of stored moisture and fuel, eg. succulents (high moisture content and therefore fire-retardant) versus pine (high resin content which is highly combustible).

Flammable plants and fire-retardant plants have certain characteristics. Get to know their characteristics in order to choose the right plants for the right place if you are going to embark on establishing this new concept of gardening.

Plant characteristics

Needle and blade-like leaves are more flammable than broadleaf plants.
Evergreen plants are more flammable than deciduous plants.
Plants that produce a low amount of litter are less flammable than those that produce a lot of litter.
High moisture content in leaves or stems are less flammable than fine or thin leaves.
Plants with sap that looks more like milky water are less flammable than plants with thick, gummy or resinous sap.
Plants with fragrant and aromatic qualities are more flammable than plants without it.
Silver or grey-green leaves have a high mineral and ash content, less flammable that those without. However, some plants, such as the highly ignitable indigenous fragrant salvia or blombos do not follow this rule.
Hairy plants are more flammable than hairless species.

All plants may catch fire, however the ability of any of these plants to retard or resist depends on their condition. Moribund, diseased, and water-stressed plants are more flammable than properly cared for plants. The essence is good housekeeping and good landscape maintenance, which is essential for fire safety, not plant selection alone.

Knysna as seen from Pledge Nature Reserve just after the 2017 fires. Photos: Supplied