The weeds are back - did you notice? It doesn’t take much rain for them to start growing again, having sneakily fooled us by lying dormant underground during the heat of the summer, just waiting for a chance to return to the surface.

Nettle invasion

I have nettles where I didn’t have nettles last year, and I thought that young, tender nettles wouldn’t sting. How wrong was I - having the welts to prove it. They are armed and loaded, delivering a potent, itching/burning sensation from the microscopic, hollow hairs in their leaves and stems that inject histamine and formic acid into the skin, even through thin gloves. They have an extensive network of spreading underground stems called rhizomes, and though they seem shallow-rooted, they can spread far, making them hard to eradicate.

Dandelions are another persistent weed, looking innocent with its bright yellow flowers, jagged leaves and hollow stems with milky sap, and cute ‘puffball’ seed heads. Now here’s a thing. As kids, we used to say that if you got the sap on your hands, you would wet the bed. Unlikely, I know, but this probably originated from an old wives’ tale taken from the plant's actual French name, ‘pissenlit’, which literally means ‘wet the bed’! This links the flower to urination and the need to pee, and the plant is rich in potassium and actually can act as a natural diuretic, giving the old myth a touch of reality.

Defensive plans

I think nearly all plants have a defensive plan to fight back; they all seem to have spikes or stinging things to stop you annihilating them. Even the most placid of things, roses, with their delicate velvety blooms that in themselves don’t last long - have thorns strategically placed along their stems. These are to prevent things from eating them, and others use those spikes as grippers to help them climb upwards to push past other plants to get to more light and space. My favourite is bougainvillaeas. Looking pretty almost year-round, languishing over walls and fences everywhere in Portugal - but thorns a-plenty. I almost got a second ear piercing by one recently, while struggling to tame it from taking over, like a viciously armed Triffid.

Cacti

And cacti are another one with defences. The prickly pear, for instance, has needles like hypodermics, and even their fruits are covered in tiny, irritating, hair-like spines, called glochids. The prickles, needles or thorns on any plant are for deterring grazers and to make them harder to consume, while also serving to reduce or preserve water or to give shade. Some little devils have hidden hooks, looking furry until you touch them, when you find out they aren’t soft at all, and the hooks are probably the hardest to get out of your skin – glochids again.

Credits: Unsplash; Author: thomas-verbruggen;

Self-Preservation

But when you think about it, plants don’t have the ability to flee predators, so some self-defence is necessary, and it’s just their personal survival instincts kicking in.

You might see futuristic movies in which the human race has long since been eradicated, and buildings are almost consumed by plants, they are just taking back. And look at derelict buildings even today – there is often a healthy sapling inside it, trying to ‘take over.’ Plants will reclaim spaces, and will cover roads, buildings and farmland. Given the chance, Nature would probably reclaim the Earth, leading to a greener planet.

Anyway, my garden is fighting back. The signs are all there – the weeds grow fast, they steal water and light, and hang on as hard as they can to their space. But I read that vinegar might help kill them off. Not the stuff you put on your fish and chips, but one of the herbicidal varieties that have 20% or 30% acetic acid, and in general, it’s said to be effective because it more completely kills young leaves and growing points. Unfortunately, it's non-selective and kills any plant, so take care, but will work well on cracks or driveways, just requiring repeat applications for deep-rooted perennials. Adding dish soap helps it stick, while salt boosts effectiveness but can harm the soil long-term.