Amy Draiss
The departure of the glory days of summer may leave many of us feeling out of sorts. Although fall can still be a life-affirming medley of color outside, we’ll inevitably be turning more of our attention indoors. Trouble is, with the seasonal shift and the drops in temperature, you’ll likely be aware of more activity associated with certain house guests you haven’t invited to join you indoors... Yes, I’m talking about spiders.
The phase from late August to October is known as spider season. For a lot of male spiders, this is prime mating season. Unfortunately, the combination of amorous arachnids and the cooler weather means many spiders are heading indoors on their quest for companionship. We all have our own ways of grappling with this unsettling upswing in spider pests. If you’re industrious, you can seal up gaps and cracks. If you’re more expressive, you might stand on a chair waving a newspaper – or lean uncertainly over a bath or wash basin with jam jars and glasses.
If none of that appeals, though, there is a simpler way – and that’s introducing plants that repel spiders. These plants work as nature’s deterrents, thanks to the fact that they emit particular smells and release chemicals that spiders find unpleasant, irksome, and ultimately off-putting. Grow these plants indoors, and you’ll have an organic and fragrant solution to the domestic problem associated with spider season. So put down that newspaper, and find out about some very welcome plants that can keep those pesky creepy-crawlies at bay.
Choosing Plants that Repel Spiders
You might not want to spend too long thinking about spiders (after all, even seeing one scuttling across the shag pile can be distressing!). Still, it’s helpful to understand a little bit about why certain plants are so effective at repelling arachnids from your cosy warm interiors during spider season.
Put simply, spiders are very sensitive to smell – using tiny hairs and receptors called sensilla to pick up vital environmental cues. Their sensilla are acutely active during the mating season. But as well as being used to hone in on potential mates, these sensilla are primed to detect and respond to vibrations and smells, good and bad, and respond accordingly.
If you can position certain fragrant container plants in choice areas of the home, you create conditions that are a lot less hospitable for spiders. Aromatic fall flowers and plants that emit powerful fragrance will challenge and confuse any spider wishing to set up home with a prospective mate. Plant fragrances can overwhelm a spider’s receptors and interfere with their ability to pick out scent trails that are important to them.
Where you can keep these fragrances pumping out in a fresh and regular supply, in the form of specific healthy plants, spiders will be discouraged from sticking around and will head somewhere else. So read on to find out about some of the best plants to repel spiders. Some spider repellants are fragrant herbs, while others are classic scented ornamentals.
1. Chrysanthemums
The pairing of mums and autumn is as natural and harmonious as peanut butter and jelly. Growing chrysanthemums is a great way of boosting morale with high impact flowering ornamentals as high summer gives way to a more contemplative season in the gardening calendar. What you might not know is that container-based mums are also great news if you want to know how to get rid of spiders in the home. As spider repellant plants go, they don’t get more vibrant than these fall-friendly favorites.
Chrysanthemums emit a chemical called pyrethrin, which is actually toxic to spiders. This chemical is used in several bug repellents, such as the BASF PT PI Pressurized Contact Insecticide Spray from Amazon (which is convenient for targeted use). You may think mums have an innocuous (albeit pleasant) nutty, earthy smell, but while they are harmless to us, this chemical causes nerve overstimulation in spiders. It can interfere with coordination, disorient the spider, and even result in paralysis. So keeping mums is a colorful yet wickedly effective way of creating problems for wayward arachnids. Buy Chrysanthemum ‘Matchsticks’ from Burpee.
2. Rosemary
Several key plants that keep spiders away come from the herbal world – and one is rosemary. While many of us appreciate the complex olfactory notes, which add an intriguing element to culinary and aromatherapy applications, the same is not true for old spidey. Arachnids are overwhelmed by the intense herbaceous hit, particularly the camphor and eucalyptol. So place some container-based rosemary plants near windows and doorways to serve as a natural deterrent. Just make sure the spot you choose receives plenty of sunlight (at least six hours, and preferably more).
Particularly strong smelling varieties include ‘Chef’s Choice’, ‘Spice Island’ and ‘Tuscan Blue’ Rosemary, which you can buy from Walmart. As a fragrant extra, why not cut some sprigs of rosemary after propagation, hanging them over doorways? You can also use rosemary essential oils in diffusers and oil burners. A few drops of an oil like Siva Organics Rosemary Essential Oil from Amazon is highly concentrated and can go a long way if you are looking to intensify your levels of rosemary potency.
3. Eucalyptus
The delectably pungent eucalyptus is my personal favorite aromatic spider repellent – possibly because it’s one of my favorite smells in the universe. Just as well I’m not a spider, or else I’d be in big trouble. It might not seem like an obvious choice to grow these fragrant beauties indoors, and it’s true there are a few caveats. You’re better off with a compact variety if you’re growing eucalyptus in a container indoors. Think pretty gray-blue Eucalyptus cinerea ‘Silver Dollar’ if you’re willing to keep it well pruned, or scalloped E. gunnii ‘Silver Drop’ kept around 65-75°F (18-24°C).
Your potted eucalyptus needs to be positioned near a window to access eight hours of sun a day – ideally south facing and preferably a conservatory, where multi-directional light is possible. You also need to be willing to monitor water levels closely, ensuring that the pot is well draining to prevent the risk of root rot. Get this right, and eucalyptus can be a devastating spider foe, as well as a handsome aromatic houseplant. Loaded with eucalyptol, like rosemary, it will muddle a spider’s navigational abilities, mask scent trails, and leave them feeling discombobulated.
If you’re not overly confident you can keep a eucalyptus thriving indoors, here’s another idea – and this one, friends, is being deployed in my house! Keep your actual plant outdoors, like my ‘Baby Blue’ – but steal a few branches for cutting, and place them in killer positions to infuriate your spider guests. I have cuttings of eucalyptus regularly infusing their aromatic loveliness around the home – gorgeous for me, not so great for the arachnids. Grow your own ‘Baby Blue’ Eucalyptus, available as a live plant from Amazon, and as insurance, grab some Siva Organics Eucalyptus Essential Oil, also from Amazon, and pop a few drops in a diffuser.
4. Peppermint
It wouldn’t be right to advocate too heavily for the science behind peppermint as a spider deterrent, as opinion is genuinely divided. On an anecdotal basis, though, two active ingredients in peppermint – menthol and cineole – are believed to be repulsive and disorienting to spiders. I’ve been known to leave cotton balls soaked with peppermint nestled against doorways, or stuffed along uneven floorboards. And for as long as I’ve been growing herbs, I’ve resolved to keep at least a couple of pots of peppermint indoors at close quarters, wherever I feel it’s needed most.
The trick with peppermint is to maintain concentrated levels around potential spider spots. You may think peppermint is losing its intensity quickly when you sit near it. Remember, a spider is receiving the chemical information in a very different way. Still, you can enhance the impact by adding a few drops of peppermint oil to water and pure liquid soap like Castile soap from Amazon. Spray wherever you suspect there may be spider activity (and repeat every few days). It’s also worth placing a few peppermint leaves in select spots, such as near a window. Buy Bonnie Plants’ Peppermint in pots from Lowe’s. And for an instant hit you can add in ready-made form, try Mighty Mint Peppermint Oil Spray from Amazon, effective on spiders, roaches, ants and more.
5. Scented Pelargonium
Organic pest controls, as noted, can sometimes be received with a measure of skepticism – but if there’s one smell that seems to be broadly accepted as a problem for pests, it’s citronella. Famed for its reputation as a mosquito repellant, citronella is often used in outdoor candles and incense. With its distinctive lemony aroma, scented pelargonium variety ‘Citronella’ works in a slightly different way to other plants here. It works by repelling the insects on which spiders feed (including flies and skeeters), making the indoor space a lot less attractive for hungry arachnids.
As a pretty bonus, this spider-fighting fragrant charmer has one more joyful treat – lovely lavender pink flowers with crimson stamps which appear each summer. Grow some Clovers Garden Pelargonium ‘Citronella’, available from Amazon in a sunny window spot to make your home a lot less yummy to spiders. Don’t be afraid to crush a few of the leaves and scatter them in areas where you need to target more keenly. I’m a big fan of these potted tender perennials, but I have learned from experience that it’s best to keep this pelargonium separate to other scented forms so you don’t inadvertently muddle up the scents and negate Citronella’s potency.
6. Lavender
What plants keep spiders away while helping you sleep better? If you really want to send your spiders scuttling for the nearest floorboard and really rest easy, there’s one heavy hitter you can’t forget – and that’s lavender. For many of us, it’s the epoch of delectable fragrance, but a well positioned potted lavender is a source of misery for Mr Spider. Again, it comes down to the intensity and peculiarity (to an arachnid) of the heady perfume.
The best lavender varieties for scent intensity indoors tend to be the English types, where the heads are more tightly bundled. So if you are able to pot up some lavender as a houseplant, try a dwarf or compact English variety such as ‘Nana Alba’, ‘Little Lottie’ or old faithful ‘Munstead’ Lavender by Greenwood Nursery, available from Amazon. Give your indoor lavenders plenty of sunshine (ideally eight hours of direct light) or a grow light where natural light sources are limited. Make sure the potting soil is very well draining and mix in some coarse sand. Keep temperatures regulated around 60-70°F (15-21°C) and free from drafts or humidity.
To bolster the impact of fresh indoor lavenders, I also grow plenty of outdoor lavender and at this time of year, I’m lucky enough to have harvested and dried plenty of floral bundles that get placed in sneaky corners of the house as the autumn nights (and spiders) draw in. You can either tie these bundles and hang from pins and hooks au naturel, or secure in organza pouches like breathable Muslin Pouches With Drawstrings from Amazon, which allow the lavender fragrance to permeate. Not forgetting a few drops of essential oil like Majestic Pure Lavender Essential Oil With Glass Dropper from Amazon in your diffuser of choice.
Finally, Don't Forget…
Hopefully keeping these plants indoors, as live plants or as fresh (or dried) stem cuttings, can reinforce specific areas of your home that might be causing concern – and help to keep spiders from taking up residence. Knowing what plants repel spiders can genuinely make life more comfortable as you spend more time indoors. To be on the safe side, though, try to see these plants as part of a wider set of deterrents.
Don’t rely exclusively on just indoor plants that repel spiders – but use them together with other controls. If you are up to the challenge, it is worth sealing up any obvious gaps or cracks that might be worrying you. And don’t skip on cleaning – dust bunnies, clutter and other undisturbed residue can all signal safe havens for spiders. Be sure to dust and vacuum regularly, to help fight the good fight through spider season.
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