Using indoor houseplants to help control insect pests isn’t a new idea, though it tends to be more common to get rid of flying bugs like mosquitoes. But you can also use plants to deter spiders from making themselves at home in your house as well.
Here are six of the top houseplants that can get the job done.
1 – Peppermint
The crisp and unmistakable scent of peppermint is an excellent insect deterrent, and can be very effective in discouraging spiders from taking up residence. Other varieties of mint can also work as a repellent, but peppermint is the most potent choice.
Keep your peppermint plants in a sunny window, and pot them in a well-draining soil mixture. When the surface is dry to the touch, its time to give them a thorough drink.
Mint is well-known as a plant that can take over a garden, and it will do the same indoors. Be ready to re-pot as the plant grows, or try to keep it trimmed down so it doesn’t over-grow its container. Splitting this prolific herb into multiple smaller parts is another option, especially if you need to spread more mint around the house.
2 – Basil
Another plant that you can add to that sunny window is basil. The aromatic oils are known to repel most insects, including spiders. It grows just fine indoors as long as you can provide it with direct sunlight for at least 4 to 5 hours a day, and a location that doesn’t get too cold.
Basil needs warm conditions to thrive. Keep soil moist and try not to let it dry out or you can stress the plant.
There are many varieties of basil, and you can try any of them for their pest-control qualities.
3 – Lavender
This traditional purple perennial is an outdoor garden staple, and its aroma will deter insects even though its very pleasant for people (see some of the other health benefits of lavender in my post about indoor plants that good for us). It’s not quite as easy to grow indoors as some of these others, but it can be a lovely and helpful plant if you have the right conditions in the house to keep it healthy.
The trick is that you need extremely good air-flow with lavender or it can suffer. That might mean a frequently open window or even a little fan to keep the air moving. During the winter months, you should have a grow light to make sure your lavender gets a full day of light even when the days are shorter outside.
Lavender can outgrow a pot in no time, so prune your plants back each year once it has finished flowering to keep things in check. You can also split larger plants into smaller pots if you want to have more lavender for the house.
Focus on Other Pests
Since spiders eat insects, you can try a different approach and focus on repelling these other bugs and depriving the spiders of their food source. When there is nothing to eat, the spiders will eventually move on by themselves. The next few plant suggestions are intended to work with this tactic.
4 – Citronella
As I mention in another article, citronella is best known as a mosquito repellent, but the lemon scent works well to drive away a whole range of flying bugs and that makes it a good home repellent to clear away any potential spider food. Having fewer of these pests in the house is a nice bonus as well.
Your citronella should have long, grass-like leaves or you may have the wrong kind of plant. Some varieties of scented geraniums are marketed as “mosquito plants” but a true citronella is far better as a repellent.
These are plants suited for tropical living and will do best indoors if there is a lot of sun and warm temperatures. Like lavender, a little added artificial light in the winter is a smart move. Fertilizer should also be part of your citronella care routine.
5 – Lemon Balm
Popular in herbal tea, you can use the leaves for your own enjoyment as the plant helps drive away common insects, like fruit flies. It’s a very easy houseplant for a gardening novice and will do fine in sun or even indirect light. If you are struggling with houseplants because you don’t have the sun exposure, go with lemon balm.
The soil should drain well, and you don’t want to let the roots stay too wet all the time. Let it dry out periodically before the next water. If you see flower buds starting, you should prune them out immediately. The leaves will lose their aromatic traits and be much less effective for you.
6 – Chrysanthemum
The insect repelling compounds in chrysanthemums are known as pyrethrins, and are a common ingredient in many natural pesticides. That sounds like something that could help with you insect problems, doesn’t it? Keep your mums in a sunny spot but not too bright or it will stop flowering too quickly.
With chrysanthemums, it’s the flowers rather than the leaves that produce the repellents you are after. So as each flower dies back, immediately pluck off the dead blossom to encourage more flowers to come out.
Unfortunately, this will be a short-lived project as mums won’t bloom repeatedly when kept as houseplants. Even so, they can be a great addition to your pest-control plans when you have spiders or other insects to deal with.
You can put them outside for the rest of the season and the natural sunlight rhythms may trigger more blooming in the future, and then you can bring the plants back indoors for more insect duty.
A Few More Tips
Spiders usually like to hang out in quiet corners, waiting for their prey. That’s where you should focus your houseplant collection, providing these areas get enough sun to keep your plants healthy.
Hanging baskets can be an effective approach, as you can place your plants near those out-of-the-way ceiling corners that always seem to attract cobwebs.
You can also take a more active technique to repelling spiders with your indoor plants, instead of just leaving them to do their jobs on their own. Plucking a few aromatic leaves, crushing them, and rubbing their strong oils in the corners or crannies where spiders are a problem will speed up their departure. Crumbled dried leaves (or flowers, in the case of lavender) can also be used this way.
Are Spiders Dangerous?
You should be clearly aware that most spiders that you would find in your house are not dangerous. Many are not likely to bite you, and even if they did, it would not result in more than a slightly itchy “bug bite.”
Unfortunately, trying to provide an accurate visual guide to all possible spider species is a little beyond the scope of this article. The ones you should be most concerned with are the brown recluse, black widow and hobo spiders. Knowing how to identify these particular species is a good idea as they are quite poisonous.
Not All Bad
Though seeing spiders in the house can send shivers up your spine, don’t forget that they do play an important role in keeping other insect populations down. A few spiders in the corner may be doing more good than harm as they catch and eliminate house flies, fruit flies and other similar pests.
But spiders can definitely be a problem themselves if their own numbers get too high. Just keep it in perspective before you decide to wage all-out war on them.