If you have a garden, there are certain things you look forward to welcoming in the summertime. Barbecues? Butterflies? Blossoms? Check, check, and check.
But just like the best parts of your garden, some weeds also flourish in the hotter months. Goosegrass, chickweed, and more thrive in the summer – so it’s a shame gardeners are being warned to put the weedkillers down during hotter months.
Iowa State University says that there’s an “increased risk of crop injury” when you use herbicides in the heatwave, putting your entire garden – not just weeds – at risk.
So, what’s going on here – and what can you use instead?
Heat makes some plants delicate, including the ones you want to keep
Anyone who saw so much as a strand of that frazzled, hay-brown grass in last year’s heatwave will know how damaging too much sun can be to your garden.
But even if your grass looks healthy, it’s likely been weakened by the current heatwave.
Matt Adams, founder of The Relentless Gardener, told Country Living that “it’s best to avoid using any weed killer during the heatwave, as it’s another unnecessary stress for your healthy grass to fight off.“
The dehydrated strands will struggle to stand up against harsh chemicals, and it might be one stressor too much for your grass’ already-tired metabolism.
So for now, you might want to put the weedkiller to one side – you could risk your entire lawn.
Despite your plants being weaker in the heat, herbicides are less easily-absorbed
Just because your weedkillers are more damaging to desirable plants in the summer, that doesn’t mean that they’ll even touch the sides of your weed population.
Adams told Country Living that “As the heat takes over, plant growth slows down and the leaves dry out, reducing the amount of herbicide that weeds can absorb – so even if you want to remove weeds, chances are they’re not budging until after the sun anyway.“
Iowa State University adds that “Weeds growing under hot, dry conditions are often difficult to control because of the development of a thicker waxy cuticle, which serves as a barrier for herbicide absorption. Such conditions can also reduce herbicide movement inside the plant.“
So basically, using weedkiller in the summer heat damages your lawn without actually tackling the issue you’re worrying about – OK, OK, I’ll back off the Roundup.
So, what can I do instead?
There’s no denying that weeds can be really annoying, and it can be hard to deal with a load of unwanted garden guests when you’ve spent ages on your beautifully-designed lawn.
Thankfully, it turns out weedkillers aren’t the only way to banish the unwanted plants.
The Royal Horticultural Society recommends a few alternative options, such as manual removal with a hoe or weeding knife.
They also suggest applying mulch or bark, edging boards, or other physical barriers around the base of your beloved blooms to smother any weeds.
And there’s a range of anti-weed fabrics, like mulch film, plastic sheeting, and cardboard, which you can use to banish any pestilent plants.
In fact, even outside of a heatwave, the Royal Horticultural Society says that it’s best to avoid chemical weedkillers when you can.
“The RHS believes that avoiding pests, diseases and weeds by good practice in cultivation methods, garden hygiene and encouraging or introducing natural enemies, should be the first line of control. If chemical controls are used, they should be used only in a minimal and highly targeted manner,” they say.
Tempting as it might be to pour chemicals over the first sign of an enemy sprout, try to resist until the winter – or consider ditching your weedkiller dependence overall. Your garden will be grateful.