by Martin Lines
Is it time to take a fresh look at the plants we normally call ‘weeds’? Technically, a ‘weed’ is any plant growing in a location where it isn’t wanted by humans. There’s no botanical classification for a weed, it’s a human-defined term rather than a scientific plant family or species.
Any plant – even a valuable crop, a prized flower, or a beautiful native wildflower – becomes a weed if it grows where it interferes with human goals or outcompetes desired plants. Farmers’ tolerance for weeds in their fields varies hugely; we have those that are on the mower as soon as they possibly can to trim up any non-farmed area to make everything look neat and tidy. Weeds seen within a crop are targeted as enemy number one with all chemical or mechanical means needed to remove them.
And then we have the farmers who have a high tolerance for weeds, and encourage the additional diversity in and around their farms, who understand the benefits they bring outweigh the importance of neatness. We even have farmers who sow different plants together so nobody knows which is the weed and which isn’t!
Weeds can teach us about soil health, ecological balance and farm resilience. It’s often the weeds that thrive in challenging conditions – they act as nature’s diagnostic tool, telling us what’s happening beneath the surface.
Compacted soil often contains plants with deep taproots like dandelions, that tell us the ground is hard, dry, and lacks oxygen. Their roots help to break up this tight earth over time. High fertility areas of soil often have thick patches of stinging nettles, indicating that the soil is very rich in nitrogen and potassium. These are often seen where old manure or compost heaps have been.
On disturbed or bare earth, the very quick arrival of weeds shows nature’s urgent need to prevent erosion and cover the soil. Allowing these plants to spring up gives you a good indication of the type of seed-bank you have in your soil, and therefore what challenges you may face later in the year. Removing a seed-bank by allowing germination before planting a cash crop can certainly make life easier in the long run.
We must learn to see the ecological value of weeds, and rethink this dated assumption that these plants are nuisances to eradicate, because we didn’t put them there. Weeds do an incredible amount to support the wider environment, and therefore our farmland and the crops within it.
Weeds are food for wildlife – many provide essential early nectar for bees, butterflies and other pollinators, before more domesticated or garden flowers appear. Providing a diversity of plants for pollinators can certainly support successful reproductive cycles, bridge ‘hungry gaps’, and even help mitigate weather impacts like this summer’s drought.
Unfortunately, many don’t understand the value of unmanaged, weedy areas for pollinators and other insects that we rely on to pollinate our crops and help manage pests, and therefore aren’t reaping the benefits of their ‘free’ support.
Our older generations valued the human use of many of these common yard plants like dandelions, clover, and purslane – after all, they are fully edible and packed with vitamins and minerals. And it’s not just the live plant that’s beneficial – the minerals they contain nourish the soil when they break down, their decaying roots feeding soil microorganisms and creating tunnels for earthworms. Some innovative farmers are even using weeds to make ‘free’ fertiliser teas and brews to add to their soil.
It would be imprudent to rush to remove a free resource from our farms before we fully understand how they can support monitoring, forecasting, and the wider ecosystem that our businesses rely upon.
This article was taken from the latest issue of CPM. Read the article in full here.
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