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If you’ve ever stepped outside to find your newly planted flower bed overturned or your vegetable garden ravaged, you can relate to my frustration. From inquisitive foxes to hungry squirrels, garden mammals wreaking havoc on your carefully nurtured plants can challenge the patience of any gardener.
This is why garden centers are filled with all sorts of deterrents, from motion-activated ultrasound devices to intimidating steel traps and even bags of dried lion dung to safeguard your precious plants. But what if a simpler, more affordable, and gentler solution lies within your spice rack: chili powder? Is this popular gardening hack truly effective?
The concept is straightforward. Like humans, garden mammals respond to capsaicin, the spicy component found in chili peppers. When it binds to receptors in your mouth and skin, it elicits the familiar burning sensation, making you steer clear of the treated area.
You may wonder why chili pepper plants are adorned with bright, attractive fruits filled with aromatic compounds, while this unpalatable molecule is part of the mix. That’s because birds lack these specific receptors. They are immune to capsaicin. Researchers suggest that chili pepper plants have evolved to produce capsaicin as a selective deterrent to keep mammals from damaging chili seeds during digestion, while allowing birds, which help disperse the seeds, to consume them without issue.
Capsaicin is so effective that it is added to birdseed to prevent squirrels from consuming it. It also deters rats and mice from raiding poultry feed, having effects on rodents that consume and destroy wildflower seeds and nests of rare ground-nesting birds.
For larger animals such as deer and badgers, the results appear less definitive. A 2005 UK field trial revealed that European badgers favored food without capsaicin but couldn’t entirely avoid it over time, nor did they learn to steer clear of it like they do with other deterrents. Given that badgers are known to dig up and consume wasp and ant nests, it’s not surprising that a little chili pepper doesn’t phase them too much, considering.
Now, regarding the complexities. These trials can be hard to compare due to the varying forms of capsaicin utilized, including pure chili powder, chemical coatings, or purified extracts. Moreover, capsaicin is not water-soluble, meaning it doesn’t wash away easily with rain. However, it biodegrades readily, so multiple applications may be necessary, especially for those with low tolerance to its effects. Recurrent exposure can increase sensitivity.
The bottom line? Chili powder serves as a safe, natural, and cost-effective method to deter mammals from your garden. By employing the hottest types of chili powder and rotating them, you can avoid habituation and apply them as needed, while keeping the rest for culinary uses.
James Wong is a botanist and science writer with a keen focus on food crops, conservation, and the environment. Educated at the Royal Botanic Gardens in Kew, London, he hosts over 500 houseplants in his compact apartment. You can follow him on X and Instagram @botanygeek.
These articles will be published weekly at:
newscientist.com/maker
Source: www.newscientist.com
