Slugs and other garden destroying pests might be a part of our natural world, but that doesn't mean you have to tolerate them being a natural part of your garden. These tips will keep your plants pest-free without harsh chemicals.
Better living through chemistry has given us off-the-shelf and factory-manufactured solutions for any problem you can imagine. Many people, however, want to forgo using harsh chemicals in their yards and gardens to avoid unnecessary chemical exposure. This guide highlights a variety of ways you can keep your landscaping lush and your gardens unmolested by pests without having to spread toxic paste on anything or use a sprayer that requires a canister mask to use safely. We'll start with the easiest solutions that you can apply now — even if you're a renter — and move onto the more time-consuming solutions that require more advanced planning. For the sake of readability we'll be referring to the space you're working on as a "garden" for the rest of the article, but all of these methods work equally as well on landscaping in general. Photo by cygnus921.
Passive Additions to Your Garden's Defences
There are three primary groups that want to wreck shop in your garden: mammals (like rabbits), insects (like tomato worms) and gastropods (like garden snails and slugs). You can find heavy artillery for dealing with all three groups on the shelves of your local home and garden store, but before you bust out the poisons and the neurotoxins, let's take a look at cheap and non-toxic ways to deter pests. Photo by dubydub2009.
Even if you're not particularly worried about exposing yourself to harsh yard chemicals and you have no pets or small children, you've still got at least one great reason for trying natural deterrents first: Poisoning the lower end of the food chain like the slugs and the insects in your yard will keep them away, but it will also deter natural predators like other insects and birds from visiting your yard. Basically you'll end up ensuring a cycle wherein you have to keep applying chemicals to deal with the problem because you've driven away the element of nature that was actually helping you.
Bring on the Coffee: Coffee grounds are a great addition to your garden. They add nitrogen to the soil, they increase the acidity for acid loving plants, and, best of all, a wide range of creatures can't stand coffee grounds. Slugs hate coffee, cats hate coffee. What's that you say? You hate coffee and have no coffee grounds to work with? Stop by your local Starbucks and ask. They have a policy of giving away their mountains of spent grounds for patrons to use for composting and other projects. Photo by Steve Snodgrass.
Bait, Trap and Deter the Slugs: Slugs are, in my humble opinion, the most annoying of garden pests. They're the veritable ninjas of plant destruction. Unless you're looking for them — and carefully — it's rare to see slugs at all, yet every night they descend upon your garden and chew the crap out of everything. You can deal with slugs a variety of ways depending on your adversity to killing them or merely redirecting them to your neighbour's yard.
Coffee grounds, as mentioned above, will deter slugs to a degree. Even more effective, and radically longer lasting, is copper. Slugs and snails hate copper. You can use copper in a variety of forms to keep them away. To keep slugs from crawling up into your potted plants you can put decorative copper tape around the body of the container. You can shield plants on the ground by buying rolls of thin copper sheeting and making rings around the plants you want to protect — when you're done it'll look like all your plants are castles in the centre of little copper fortresses. Alternatively you can buy pot scrubbies made of copper mesh — snip the tie in the centre of the scrubbie and then uncoil the copper mesh into a long tube to wrap around your plants. If you're building copper mesh barriers for lots of plants it will likely end up being more economical to just buy a commercial roll of copper gardening mesh.
If your attempts to deter slugs are a failure, you'll have to start trapping them. Slugs are, as one would imagine, as dumb as they look. You can make an effective slug trap with little more than an orange rind or a shallow container and some grape juice or beer. Save the half-rinds from citrus fruits like grape fruit and oranges and place them about your garden. Slugs will flock to the rind. Come morning you can throw the rind in the trash or put it on top of your compost pile to dry them out in the sun and mix them into your compost. You can also put saucers of grape juice or beer around the garden. The slugs will dive in and drown. Photo by Sustainable Echo.
Repel Insects with Organic Sprays: There are an abundance of organic recipes online for insect-repelling plant sprays. The majority of them have common ingredients like garlic cloves, hot pepper and sometimes the essential oil extract of either or both. Mixtures of the two work great for repelling everything from bugs to bunnies. This step-by-step guide will help you make a potent garlic/pepper mix for your plants.
Deterring the Big Pests
If slugs are the most annoying little pests, adorable yet destructive creates like rabbits and are the most annoying big pests. A few rabbits can reduce a thriving garden patch to waste or a hearty stand of hostas to nubs in a matter of days. Unlike the simple orange-rind traps you use for slugs, you have to be a little trickier with larger pests. Photo by wwarby.
If you can afford it and it's feasible to do so, putting up a fence is the only fool-proof way to keep animals out of your garden. Barring building a rabbit-proof fence, the most effective deterrent for large pests is to scare the hell out of them. You can spray plants with nasty tasting substances like the garlic/pepper spray above, but that's not as effective or far reaching as introducing the scent of predators.
Apply Bloodmeal Liberally: Bloodmeal is a byproduct of meat-packing plants. Its dried and flaked blood and animals strongly dislike the smell of it. Prey animals like rabbits and deer are spooked by the smell of blood, even old dried blood. Bloodmeal is also extremely high in nitrogen and a great additive for your garden. Sprinkle it around your plants and in your garden beds. Take care, however, not to sprinkle the powder directly on the plants. The high nitrogen content can burn the leaves.
Introduce Strong Scents: If you have a strong aversion to spreading bloodmeal all over your yard, you can also introduce other strong scents, like bars of scented soap, cheap perfume and other strong smells. A neighbour of mine has kept her beautiful hosta beds unmolested for years now using Irish Spring soap on stakes throughout the garden.
Bring in the Predators: You won't literally invite predators — your neighbours wouldn't approve of your use of coyotes as garden patrol — but you do want their scent. For about $US30 you can purchase fox and coyote urine. Fox urine is great for repelling small animals like rabbits, squirrels and skunks. Coyote urine is great for bigger pests like deer, raccoons and opossums. You use it by putting a few drops around the perimeter of your garden and plants. A $US30 bottle will last you all season even with a fairly large yard as those few drops usually linger for a week or two barring a heavy rain storm. If you're curious, no, human urine doesn't work very well. Photo by mikebaird.
Scare 'em Off With Water: Scarecrow sprinklers look like regular lawn sprinklers, except they have a battery-powered motion sensor. Anything that gets in the path of the sensor gets a sudden and intense blast of water. I've never used one personally, but everyone I know that has one swears by them. They run $US50-$US75, but they're great for everything from squirrels to solicitors.
Plant Pest Resistant/Repellent Plants
This is by far the most long-term and expensive solution to pest problems. Some plants are more resistant to attack by pests than others whether due to bad taste, tough fibres, thorns or other natural deterrents. We can't provide a blueprint for your yard, but we can provide some suggestions and point you in the right direction. There are two schools of thought when it comes to using deterrent plants. The first school is focused on planting the deterrent plants as the main course in your landscaping and gardening adventures — selecting plants right from the start that keep the deer away and the bugs off. The second school is focused on companion planting. Instead of giving up on the plants you love but aren't particularly resistant to pests, you instead plant your garden in pairings where naturally repellent plants are located near more vulnerable plants. A common pairing in gardens is tomato plants with oregano and basil. Not only are oregano and basil great for tons of tomato-based recipes when it comes time to harvest, but both plants are strongly-scented and great at repelling pests. Photo by The Marmot.
Your best bet is to check with your local nurseries, nature centres and university extension offices to see what plants grow best in your area and afford natural pest protection. Searching Google for local gardening guides and gardening groups can also be very fruitful. To get started check out some of these guides: Companion Plantings: The Natural Way to Garden, pest-deterrent herb pairings, pest-resistant ornamental plants.
Whether you're doing it for yourself, for the safety of your kids, or to keep your goofy golden retriever from eating toxic slug-killer, it's possible to radically reduce the number of pests in your garden without resorting to hosing your yard down with a soup of harsh chemicals and toxins. Have a favourite tip or trick we didn't highlight here? Let's hear about it in the comments. Since gardening tips are often region/climate specific, help out your fellow Lifehacker readers by noting where your tip has been effective.