On the grounds of Rahamim, there is a fig tree that has made its home in the soil right next to the wall of the heritage building. There is concern that this tree is going to cause damage to the foundations of the building. This is a fair fear. Fig trees have quite a reputation of roots causing damage to buildings. In a staff meeting it was suggested to apply some Roundup on the tree to kill it – and then there will be no further problems. This has raised many ethical discussions. With Earth being our main focus and ministry, how can we be good custodians of Earth as well as getting along with the human community and all of the expectations that comes with humans? And what is wrong with using Roundup anyway?

Roundup is a broad-spectrum herbicide. Its purpose is to kill any and all plants that it makes contact with – what we generally call “weeds”. A weed is understood to be any plant growing in the wrong place.

What are weeds?

Weeds are a human construct. All weeds have a function in Earth trying to heal and cover the soil. There are all sorts of plants that we deem to be weeds. Dandelions, cathead, onion weed, blackberry, willow, asparagus fern, thistles – to name but a few. The list is incredibly comprehensive. We all have them in our little patches of Earth.

What are the weeds doing?

All ecosystems are working towards a climax species – which in most cases is a tree and the supporting shrubs, bushes and grasses that support the community of life. Where does the journey start? Bare soil is the beginning of the journey. Every time we disturb or till the soil, we are recreating this origin of the journey. Nature is incredibly fragile in this state. Earlier on this year we saw the result of bare soil in the centre of Australia. The wind picked it up and dumped it across the Eastern states and into the ocean. The only way for nature to protect this soil is to cover it.

The first species that would grow in bare soil is moss or lichen. Small leaves that cool and moisten the soil and make the right conditions for the next species. This would usually be a broad leaf weed that has a light seed that is dispersed by the wind. Enter the dandelion, or a similar habitat of weed with a tap root that opens the soil up for aeration and water infiltration, leaves that spread out over and cover the earth, creating moisture, moderated temperature and the right conditions for the next species. Grasses follow, then bracken, woody weeds and then small shrubs, fast growing soft wood trees, and then the hardwood species – we have reached the climax.

At each stage of plant succession the soil has also developed to support the community of plants – involving a complex web of life in the soil that includes micro and macro life forms, fungi and bacteria that live in harmony with the plants that now exist.

What do we do about weeds?

Each time Roundup or glyphosate is used it takes the soil back to the beginning of its journey. The same weeds will return year after year. Rather than using glyphosate, the best way to deal with weeds is to change the conditions for the weed either by taking the succession forwards or backwards. The conditions for blackberry will change if there are more trees growing up and over the plant and therefore less sun accessing the plant. The shade will reduce the amount of photosynthesising the plant can do, and thus reducing the amount of sugars in the roots. A plant will only grow if it is able to photosynthesise.

To deal with our rogue fig tree, we will be cutting back as many leaves as possible until the sugars in the roots are all used up and the tree’s energy is exhausted. It will also be necessary to plant other shrubs nearby to crowd out the tree and to stop the light getting to any leaves that are left behind.