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If you’ve spent time tending to your garden, you’re probably no stranger to the challenges posed by common pests. It’s true that chemical pesticides are an option, but they can harm the very insects that make your garden thrive and take a toll on the environment.
For those of us seeking a greener, eco-friendly alternative that says ‘no’ to harmful chemicals, pest-repelling plants are a fantastic choice. They’re not just effective; they can be the champions of your garden’s defense. In this guide, we’ll walk you through how to protect your garden from these pesky intruders using natural pest-repelling plants.
How do Some Plants Repel Garden Pests?
Plants have a range of unique adaptations and this includes the ability to resist pests. This isn’t something we see in all plant species, but some have a chemical defense to keep pests at bay.
For example, some plants are able to produce chemicals like phenols, alkaloids, and terpenes, which are essentially natural pesticides. Not only do these chemicals repel pests but they may even interfere with their breeding and feeding activities, driving them to seek out alternative locations.
Many pest-repelling plants, like lavender, emit aromas that are repulsive to pests. This is because of a compound called linalool which is very effective in deterring pests like moths and mosquitoes. In some cases, plants are able to release such potent scents that they’ll even mask the attractive odors of neighboring plants.
Moreover, there are certain scents that mess with the olfactory systems of bugs and disrupt their activities. For example, many critters use odors to find a mate, but when the scents from these plants are strong enough, they override the insect’s ability to sniff out pheromones from a potential mate. However, at the same time, these scents that are unattractive to pests may be super attractive to beneficial insects and pollinators.
Some plants even possess toxins that are highly irritating to pests, and this deters them from wanting to feed on them. However, it’s usually best to plant a series of different species together and in some cases, certain plants can be companions to others. For example, nematodes are highly disruptive to tomato plants but they hate marigolds. By planting these two species together, you can grow your tomatoes safe in the knowledge that any pests will be deterred by the presence of the marigolds.
Benefits of Using Plants to Repel Insects
Using plants to repel insects is one of the best things you can do for your garden. It’s totally natural, and it keeps your garden looking great. Let’s take a look at the many benefits you can expect.
- Plants are an eco-friendly way to repel pests from your garden and help you to avoid the need to use chemical pesticides which can be harmful to beneficial insects and the environment. Chemical pesticides can contaminate soil, harm birds, and spoil crops.
- Where crops are concerned, you may not spray chemical pesticides anywhere near them but runoff is very real and even if you use the chemicals on the other side of your garden, there’s still the potential of them running off to your crops.
- In addition to being safe for the environment, plants are much safer for you, your family, and your pets. Chemicals contain ingredients that are toxic to humans and animals, so pose a serious safety risk.
- Your garden is also filled with beneficial insects like bees and butterflies that are pollinators. Other insects, like spiders, help to control insect populations as they are predators. Keeping these beneficial bugs safe is imperative to the overall health of your garden, and plants pose no risk to them.
- Attracting beneficial insects and other wildlife to your garden helps to maintain balance. With lots of pest-repelling species, this is more than possible.
- By adding lots of pest-repelling plants to your garden, you’re creating an aesthetic haven at the same time as addressing a practical concern.
- Your plants will be much healthier when pest-repelling species are included in your garden as they’ll be under less stress. When plants are exposed to pest infestations, so much damage can be caused that there’s a good chance the plant will die.
- Chemical pesticides can be pretty expensive, and you have to continue to buy these products. However, using plants is far more cost-effective as you only need to buy them once, which means your bank account doesn’t take as heavy a hit.
Herbs That Repel Pests
Herbs are often used for culinary purposes and tend to be highly aromatic. These plants have some unique ways to deter pests.
1. Rosemary (Salvia rosmarinus)
Rosemary is an excellent choice if you’re looking to repel flying insects like mosquitoes, cabbage moths, and carrot flies. However, it’s also a good deterrent for some beetle species. The way it works is that rosemary gives off a strong scent thanks to compounds like camphor and rosmarinic acid which disturbs the insects’ ability to follow natural attractive scents given off by their hosts.
Moreover, having rosemary in your garden is a great way to attract butterflies and bees, which are important pollinators and will ensure the reproductive health of your garden and the local area. And lets’ not forget that this herb can be harvested and used in recipes; it’s especially good with lamb and in herbal tea. Just be sure not to harvest more than ⅓ of the leaves at a time. Furthermore, cut the plant just above the leaf stem when harvesting.
Rosemary flowers in the late spring and early summer with pretty blue blooms, so it’s a beautiful addition to your garden. Planting it alongside beans, carrots, and cabbage will protect those crops from pests. Just be sure to leave around 18 inches (45 cm) between plants to encourage air circulation.
Be sure to place rosemary in well-drained soil and in a spot where it will receive at least six hours of sunlight a day. In colder climates, it may be better to grow rosemary in a container that can be transferred indoors during winter. Note that it thrives best in zones 8 to 10.
Rosemary releases its odors well when the leaves are crushed. Of course, you don’t want to crush your plant, but regular pruning and cutting will encourage the emission of these compounds, making the plant more effective against pests. You can also take cuttings for propagation.
2. Mint (Mentha spp.)
Mint is a diverse plant that grows in zones 3 to 11 and, while it does prefer full sun, it can tolerate some shade throughout the day, making it suitable for a variety of gardens.
There are more than 600 mint varieties, each one having its own aroma and flavor, again proving that this is a versatile plant that can be used in cooking and has medicinal properties. For example, it’s known to ease digestive distress and soothe nausea.
If you’re planting mint in the ground, keep in mind that it prefers well drained soil. However, it’s also important to acknowledge the fast spread of this plant, so growing it in pots is often preferred to avoid it taking over. You can always take cuttings from the potted plants to grow more, and don’t forget to regularly harvest as this will encourage growth.
While mint may require a bit more care than other plants, it’s a worthwhile addition to your garden as the strong scent is a natural deterrent for pests like mosquitoes, ants, and cabbage moths. It’s thanks to the well-known compound menthol, which is also known to repel rats
As well as repelling pests, mint also serves as an attractive plant for things like pollinators because it flowers in summer. What’s more, predatory insects like wasps to further keep pest populations under control. If you’re an arachnophobe, you’ll be pleased to know that spiders hate the smell of mint.
Plant this species alongside tomatoes, cabbage, and broccoli to protect them from things like cabbage worms and aphids.
3. Basil (Ocimum basilicum)
It is estimated that there are around 50-150 basil varieties and, like mint, each one has its own flavor and aroma. Basil contains a number of aromatic compounds like linalool, limonene, and geraniol, which are highly repulsive to pests like aphids, whiteflies, and mosquitoes. However, these same compounds are very attractive to pollinators as well as hoverflies which prey on pests.
The aromas mask attractive odors, throwing pests off the scent, and basil is particularly useful as a companion plant to peppers, tomatoes, and asparagus.
These plants like to be placed in full sun and require well-draining soil. Basil will grow best when the soil is topped up with organic matter, such as mulch that contains comfrey leaves. When placing basil, be sure to leave at least 8-12 inches (20-30 cm) between plants for excellent air flow, which will help to prevent disease. Prune regularly by pinching off the tips and this will encourage better growth. You can also harvest basil as often as you like, and it goes great in pasta dishes and pesto.
Basil is typically an annual plant and thrives in zones 4 to 10 and can be grown in a container or in the ground. What I love about this plant is not only its effectiveness against pests but also that it smells incredible as you walk past it in the garden.
4. Chive (Allium schoenoprasum)
Chives have a strong scent that’s reminiscent of onions since they come from the same family. However, this plant is considered a herb and is used in salads, sauces, and garnishes. You can eat the leaves, but when the plant flowers in late spring, you can also eat the small purple flowers. These flowers are also very attractive to pollinators like bees, so are great for bringing beneficial insects to the garden.
In terms of repelling pests, chives are very effective owing to the sulfur compounds they release, including allicin and sulfides, as well as ethyl. This is what gives them their scent that pests like Japanese beetles and aphids cannot stand.
Chives are commonly used as a companion plant for carrots, tomatoes, and roses. However, when planting them, make sure to do so in a sunny spot. While they can tolerate a little shade, full sun is preferable as well as being placed in well-draining soil. Chives are relatively adaptable to different soil types but do best where the soil has a pH between 6.0 and 7.0.
Chives are best grown in zones 3 to 9, and depending on your region, they may grow as an annual or a perennial. If you can’t or don’t want to grow them in the ground, then it’s perfectly acceptable to grow chives in a container. Just be sure to cut the leaves at the base to encourage better growth. You can also divide plant clumps and repot them separately.
5. Dill (Anethum graveolens)
Dill is a member of the celery family and is an annual herb which grows best in full sun and well-draining soil between zones 3 and 11. Keep in mind that dill is very frost sensitive so, in colder climates, it may be best to grow it in pots and bring it indoors in winter.
This herb is used for many culinary applications, including pickling, seasoning, and as a salad ingredient. What’s more, it’s known for its health benefits, including soothing digestive issues and for its antioxidant properties. If that wasn’t enough, it has beautiful, feathery leaves that look great in the garden.
There are three main compounds that create the pest-repelling odor of dill which are dill ether, myristicin, and phellandrene. This strong aroma repels pests like spider mites, aphids, and cabbage loopers and the plant is an ideal companion for cucumbers, cabbages, lettuce and other crops that are plagued by these insects.
As well as deterring certain bugs, dill is also known to attract predators like ladybugs, which also help to control aphid populations in the garden. The plant typically flowers in summer, but allowing it to bloom excessively can cause leaf growth to die back, so pruning and harvesting the plant is important.
One of the great things about dill is that it is self-seeding, meaning the plant will keep coming back with less maintenance from you.
6. Oregano (Origanum vulgare)
Oregano is a member of the mint family and there are around 45 varieties of this herb which are often used in cooking in dishes like pizza and other Italian cuisine as well as in sauces. Oregano contains many aromatic compounds like thymol and limonene which are highly unattractive to pests as they interfere with the insects’ ability to pick up on attractive scents from its host plants.
For this reason, oregano makes a great companion for crops like broccoli and beans that would otherwise be attacked by such insects as aphids, cabbage worms, and spider mites. However, this plant will also attract beneficial insects to your garden, including both pollinators and predators, both of which will contribute to a balanced and healthy garden ecosystem.
Oregano is a perennial plant that does well in zones 4 to 9. It prefers a bright spot with at least 6 hours of sun each day and benefits from well-draining soil. That said, this plant does adapt well to various soil types, making it an easier option to grow, and it can be grown in a container. However, it does require a good amount of space so make sure to place plants at least 18-24 inches (45-60 cm) apart.
When caring for oregano, you’ll need to prune it regularly to encourage better growth. You can harvest it whenever you please, but for the best flavor, wait until the plant is just about to flower which usually happens in mid to late summer.
7. Lemon Balm (Melissa officinalis)
Lemon balm is an ideal plant if you’re looking to attract pollinators as butterflies and bees love it. However, since this article is about plants that repel pests, you’ll be pleased to know that this species, from the mint family, is great at deterring mosquitoes, gnats, and other flying pests.
It has a strong citrusy scent, which derives from compounds like citronella and geraniol as well as rosmarinic acid, also found in rosemary. These scents cover up attractive fragrances from host plants, making lemon balm an ideal companion for broccoli, tomatoes, and sweet peas.
Keep in mind that lemon balm grows best in zones 4 to 9 and requires fertile, well-draining soil. The great thing about this plant is that it’ll do well in both full sun and part shade, although it is known for its wide spread so may be best grown in a container to keep the plant under control.
With a refreshing aroma, lemon balm makes a wonderful addition to the garden and can be used in herbal tea as well as a natural digestive aid. You can harvest the leaves for these, and other applications, as often as needed and the more you do, the more the plant will grow.
8. Sage (Salvia officinalis)
Sage is yet another member of the mint family that works really well as a pest-repelling plant. It has a strong aroma that comes from compounds such as camphor and thujone, which are repulsive to bugs like cabbage moths, beetles, and carrot flies. The aroma affects their ability to follow attractive odors from host plants like carrots and cabbage, which makes sage an excellent companion for these crops.
Sage is also an excellent choice if you’re looking to attract pollinators to your garden and improve its health. It’ll also attract predators like hoverflies, which will further help to keep pest populations under control.
Like other members of the mint family, sage will grow well in full sun, so be sure to find a spot that gets at least 6 hours of light each day. Note that this species flourishes in zones 5 to 9 as a perennial plant and enjoys being in fertile, well-draining soil. You should also remember that sage is prone to root rot, so overwatering should be avoided at all costs.
Sage is used to add flavor to dishes, especially white meats and vegetables and can also be used as a digestive aid. It can be harvested as often as needed, but you’ll get the most flavor just before the plant flowers in mid to late summer. Make sure to keep on top of pruning, as this will encourage the release of aromatic compounds and keep the plant in check. However, if you want the best control or if you have a smaller garden, you can grow it in a container.
9. Catnip (Nepeta cataria)
Catnip is most commonly associated with the effect it can have on cats, such as excitement or aggression and even relaxation. However, while you do need to be mindful of your pet’s reaction, this is a great species if you’re looking to repel pests.
Catnip contains a compound called nepetalactone which has a very strong aroma that pests cannot stand. As is the case with many other plants, this compound affects the insects’ ability to sense attractive smells from host plants such as eggplant and tomatoes. For this reason, it’s a great companion species for these crops and will deter insects like flea beetles and aphids. Studies have also shown that catnip may have an impact on mosquitoes. What’s more, this plant is fiercely attractive to butterflies and bees, which are important pollinators.
You will have the greatest success growing catnip in zones 3 to 9 as a perennial, and this plant will do well in full sun. However, it can also tolerate some shade, making it ideal for a wider range of gardens. Just remember that this plant grows very rapidly, so it may be best to grow it in containers. In any case, make sure that the plant benefits from well-draining soil.
While catnip has a beautiful fragrance and is a wonderful addition to the garden, it’s also a great choice for herbal tea and can be harvested as required. I’d also recommend staying on top of pruning, as this will encourage the plant to become bushier.
10. Thyme (Thymus vulgaris)
Thyme is a popular herd in meat dishes and can be harvested from the garden as often as you need. As with other plants, it’ll have the most flavor just before it flowers which typically happens between June and October.
Not only is thyme highly aromatic and pleasant in the garden, but these same aromas, derived from compounds such as carvacrol and thymol, are also highly repulsive to pests. These pests include tomato hornworms, cabbage worms, and pesky mosquitoes, making this plant an ideal companion for cabbage, tomatoes, potatoes, and eggplant.
Aside from this, the flowers, which come in purple and pink to white, are attractive to pollinators as well as predatory insects like wasps. These wasps will prey on pests like aphids and act as another form of natural control for your garden.
Thyme grows well in zones 4 to 9 and requires a bright spot with at least 6 hours of sun each day. It’s easy to grow, largely because of its tolerance for a variety of soil types as long as the soil is well draining. Do keep in mind that good air flow is necessary, so allow 12 to 24 inches (30 to 60 cm) of space between plants. Alternatively, you can grow thyme in a container.
11. Cilantro (Coriandrum sativum)
Cilantro, sometimes called coriander, is a highly aromatic herb that’s often used in Asian cuisine. It has a fresh aroma and belongs to the Apiaceae family of herbs which also includes celery and parsley. Both the seeds and leaves of this annual plant can be harvested, but it’s important to keep the plant in a cool, shady spot in hot weather to prevent it flowering prematurely.
Cilantro releases compounds like y-terpinene and linalool which are highly effective in deterring pests as they interfere with their senses. Insects that are affected by these compounds include spider mites and aphids, as well as the potato mite. Planting cilantro with peppers, tomatoes, beans, and a variety of other legumes will help to prevent pests. The presence of this plant will also attract predator insects like hoverflies and wasps, which will further help to control pest populations.
When growing cilantro, some sun is required, but as I mentioned earlier, a degree of shade is necessary, especially in hot weather. It grows well in zones 2 to 11 and needs highly fertile, well-draining soil. Cilantro is a plant that requires regular watering so be sure to keep the soil moist.
You can grow cilantro either in the ground or in containers but it is recommended to plant successively every few weeks to ensure continuous growth and a healthy harvest.
12. Fennel (Foeniculum vulgare)
Fennel is another plant belonging to the celery family and has a unique aniseed aroma and flavor, which is popular in Asian and Mediterranean dishes, as well as in herbal teas. This aroma comes from a compound called anethole which is also found in things like anise. Bugs like slugs, snails, and aphids can’t stand the smell of fennel as it interferes with their sensory mechanisms.
Aside from deterring certain insects, fennel is also great at attracting beneficial ones like parasitic wasps that will prey on aphids as well as pollinators like bees. Planting fennel around your tomatoes and peppers will have a great effect on pest activity.
Not only can you use the fronds of the fennel plant, but the seeds are also commonly used in cooking and are said to have anti-inflammatory properties as well as helping to maintain a healthy weight.
Fennel grows best in zones 4 to 9 as a perennial and prefers fertile, well-draining soil. It’s best to place it in a sunny position, but it can tolerate a small amount of shade. If you’re planting in the ground, make sure to leave at least 12 inches (30 cm) between plants to optimize air flow and prevent disease. However, if you have a small garden then you can grow fennel just as easily in a pot.
13. Lavender (Lavandula)
Lavender is one of the most highly fragrant herbs there is and is often used for its calming properties in aromatherapy. In the garden, it boasts a stunning aroma that’s pleasant to humans but for bugs like mosquitoes, moths, and fleas, it’s a very good repellent.
There are around 39 species of lavender, but French, English, and common lavender are the most common in the garden and grow best in zones 5 to 9. This plant handles dry climates very well and needs to be placed in a sunny position. Soil needs to be well draining as if the plant is left in moist soil, it becomes susceptible to root rot.
As well as being used for its therapeutic properties, lavender is also an excellent culinary herb, especially in desserts and sweet treats. It blooms pretty purple flowers, but you should harvest before these reach full bloom as the plant will contain the most oil at this point. And it isn’t just you that will benefit, pollinators like bees love lavender so will arrive to maintain the health of your garden.
Planting lavender alongside a variety of fruits and veggies will help to protect them from pests and this is thanks to compounds like linalool which produces an aroma that’s unattractive to bugs.
Flowers That Deter Pests
Flowering plants often need to attract certain insects for pollination. At the same time, they need repellent traits to deter pests that may cause them harm.
1. Chrysanthemum (Chrysanthemum)
Chrysanthemums, more commonly and lovingly referred to as simply ‘mums’ are flowering plants that produce blooms in an array of colors from pinks and whites to orange, cream, and even burgundy.
These flowers contain a compound called pyrethrin, which is toxic to certain bugs and acts as a natural insecticide. However, this compound can also be dangerous to mammals, including humans and may cause skin irritation, so it’s important to handle them with care and keep children and pets well away.
So effective is this compound that it’s often featured in insecticide products and works against pests like spider mites, whiteflies, and aphids. However, there are some insects who are unaffected by this, mainly pollinators, which are beneficial to your garden and will be attracted to the chrysanthemums.
This species, from the aster family, has around 40 varieties, but not all of them act as a natural repellent. For this reason, it’s important to choose those that contain high levels of pyrethrin. Plant them around peppers and tomatoes to protect your crops from pests.
Do make sure that your mums get at least six hours of sunlight each day and are planting in fertile, well-draining soil otherwise they will be prone to root rot. Chrysanthemums grow best in zones 5 to 9 and can be planted in the ground or in pots. What’s great about them is that they’re a late bloomer, giving your garden a pop of color in fall.
2. Petunia (Petunia)
If you’re not very green-fingered, then petunia would be a good option as it’s a very low maintenance plant. They also continue to bloom beautiful flowers in a range of colors like pink, red, white, and yellow. However, it is important to deadhead the plant regularly to ensure it continues blooming.
While they can be planted in the ground in well-draining soil in zones 9 to 11, they also do well as a container plant. Also be sure to find a sunny spot for your petunias as this further encourages healthy flowers.
There are 35 varieties of petunia and each one has its own traits, but they’re all very effective at deterring pests thanks to their strong aroma. They are one of the only plants that don’t rely on chemicals to repel insects. However, things like aphids and leafhoppers will stay well away while butterflies, bees, and hoverflies will be attracted.
As a companion plant, petunias work excellently with a variety of crops as their potent, yet pleasant aroma will keep pests at bay.
3. Pot Calendula (Calendula officinalis)
Thriving in zones 3 to 9, pot calendula is great at repelling white flies, aphids, and nematodes. This is because of the presence of a compound known as alpha-pinene as well as others like limonene that have a strong scent, driving pests away.
Not only this, but the brightly colored, usually orange flowers, are highly attractive to predatory insects like ladybugs. So, you’re not only combatting pests with the scent of the flowers, but they’ll also be preyed upon and therefore better controlled.
Pot calendula is best planted in full sun but will tolerate a small amount of shade during the day, especially if it is planted in rich, well-draining soil. That said, this is also an excellent candidate for container planting, making it ideal for balconies, terraces, and small gardens. However, it also makes a wonderful companion plant for peppers, beans, and tomatoes.
If you want your pot calendula to be most effective, be sure to deadhead regularly, as this will encourage new blooms. While the plant starts flowering in June, it’ll continue through to mid-September, making it a wonderful addition to a fall garden.
What’s more, the flower petals are edible and are a lovely addition to herbal teas and salad. Their bright appearance also makes them an excellent natural food coloring. When eaten, this species has several health benefits, including reducing inflammation.
4. Scented Geranium (Pelargonium)
Mosquitoes can be a real nuisance in the garden, and scented geraniums are one of the best plants to deter them thanks to their high levels of fragrant oils like citronella which act as a natural repellent. But it isn’t just the mozzies that will be sent packing, other insects like flies and beetles also hate this plant.
Scented geranium comes in a host of varieties, including regal, garden, and ivy geraniums, and each one has its own beautiful scent that ranges from lemon to mint and much more. The flowers also come in a huge range of colors so they make a bright addition to your garden. In order to get the best blooms, be sure to prune the plant regularly.
These plants grow best in zones 9 to 11 and prefer a sunny spot with a small amount of shade. They thrive in fertile, well-draining soil but can also be grown in pots. Take cuttings from your ground plants and transfer them to a pot.
As a companion plant, scented geraniums work very well with many species, including crops like corn, grapes, and cabbage where they’re very effective against Japanese beetles. They can also be used by humans for their aromatic properties and the leaves are often used to make tea or even pot pourri.
5. Borage (Borago officinalis)
Borage is considered to be one of the best plants for attracting bees, so if you want to bring pollinators to your garden, the pretty, blue, star-shaped flowers are sure to draw attention. But since this plant also contains pyrrolizidine alkaloids, it is toxic to pest species. It’s not as effective as other plants on this list but coupled with other species, it can work well, especially when planted alongside squash, strawberries, and tomatoes for pest control.
This plant grows well in full sun and requires well-draining soil. One of the major benefits is that borage adds trace elements to the soil, keeping it healthy. What’s more, this is a self-seeding plant, so it’ll reappear every year.
Another great thing about borage is that it thrives as an annual in most USDA zones between 2 and 11. It’ll grow well in the ground but also as a container species, so it’s very versatile and can even be eaten in salads or used in herbal tea. It’s said to have many health benefits, including soothing a cough and helping with depression.
6. Anise Hyssop (Agastache foeniculum)
Upright clumps of purple flowers bloom from the anise hyssop between June and September, and these are extremely attractive to pollinators like butterflies and bees. If there are hummingbirds in your local area, they will also love these plants. Anise hyssop also attracts predatory insects that will help to control pest populations in your garden but since anise hyssop contains anethole, the same compound found in fennel, it’s great at naturally repelling pests all by itself.
This species is an excellent companion for cabbage, tomatoes, and broccoli and will deter pests like cabbage loopers, white flies, and aphids.
Anise hyssop thrive between zones 4 and 9 and should be planted in a sunny position. However, it does tolerate small amounts of shade and can be placed in a range of well-draining soil types as it is quite adaptable. You can also grow this species in containers if you’re limited on space in the ground.
Make sure that you regularly prune the plant by removing dead flower heads, as this will encourage more blooms to appear. You might also harvest the leaves which can be used in herbal tea, and they’re believed to have many health benefits, including soothing a cough, easing diarrhea, and treating wounds.
7. Nasturtium (Tropaeolum majus)
Nasturtium is actually in the same family as broccoli (Brassicaceae) and contains mustard oils, which cause it to have a very peppery aroma that insects like whiteflies, aphids, and squash bugs cannot stand. For this reason, it’s a great companion plant for cucumbers, cabbage, and tomatoes but also serves to attract a range of beneficial insects like ladybugs that will prey on pests.
Nasturtium grows best in USDA zones 9 to 11 and it’s important to keep in mind that it is incredibly sensitive to frost and will not survive these conditions. You’ll need to place nasturtium in full sun and well-draining, rich soil. However, be careful not to use soil that’s too rich otherwise this will cause the leaves to outgrow the flowers.
Flowers bloom in a variety of colors, including red, cream, orange, and yellow, which appear in summer and continue through until autumn. The flowers can be harvested for their petals which have a rich, peppery taste that goes very well in salad dishes.
There are around 80 known varieties of nasturtiums, and some are trailing while others are climbing. This makes them excellent choices for hanging baskets and trellises or a wonderful addition if you’re looking for a ground cover plant.
8. Allium (Allium)
Allium is a huge family of flowering plants that includes things like garlic, shallots, chives, onions, and leeks. Many species are highly prized for their showy flowers, which come in a range of colors, including purple, pink, white, and blue. They typically flower in spring, with some varieties continuing well into summer.
Like the chives I discussed earlier, alliums have sulfur compounds that are highly repellent to insects, including cabbage worms and carrot flies. For this reason, they are fantastic companion plants for things like carrots and tomatoes, which these bugs typically affect.
But while they drive certain species of bugs away, alliums are also very effective in attracting beneficial insects like bees and hoverflies. Bees will ensure effective pollination in your garden, while the hoverflies will prey on pests.
Some people grow alliums for their aesthetic value, while others harvest them for cooking owing to their unique flavor. In any case, you’ll need to use well-draining soil and plant either in the ground or in a container. Find either a sunny or partly sunny spot for your alliums, and make sure to allow a good amount of space. For smaller species, place plants 4 inches (10 cm) apart, while taller varieties should have at least inches 8 inches (20 cm) of space.
Alliums grow in USDA zones 3 to 11, but which thrive best in your zone will depend on the climate and allium variety, so it’s worth researching beforehand.
9. Pitcher Plant
One of the most unique ways that certain plant species control pests is by eating them! The pitcher plant is a great example of this. It’s a carnivorous plant that actually benefits from the nutrients within the insects it traps. This is because, in the wild, these plants grow in nutrient poor soils that don’t provide them with the resources they need. Over time, they’ve adapted to get their nutrients elsewhere; in this case, insects.
Pitcher plants have cup-like structures that are filled with digestive fluids, allowing them to consume any insect that falls inside. And once the insect is in there, tiny hairs around the edge of the pitcher prevent it from escaping. While the plants may trap a variety of insects, it most commonly catches mosquitoes and ants.
The pitcher plant is a tropical or subtropical species and will need to grow in the right conditions. While they might not thrive outdoors in temperate climates, it is possible to grow them indoors or in your greenhouse as long as there’s a good level of humidity.
There are around 100 different varieties of pitcher plant, so plenty to choose from, and each one has its own unique appearance in terms of shape and color. You won’t be able to use these plants as companions to your crops because they simply won’t tolerate the same soil or light conditions.
Generally speaking, pitcher plants need to be placed in a bright spot but not in direct sunlight and require well-draining soil covered in sphagnum moss and perlite. In the wild, they’re typically found in boggy regions, and these natural materials help to mimic this.
10. Lantana (Lantana)
Growing in zones 9 to 11, lantana is a genus that contains around 150 species. Each of these species contains a compound known as lantadene which is described as having a very earthy aroma. This aroma is unattractive to insect species like flies and mosquitoes as well as several species of ants. However, the flowers, which grow in colorful clusters, are very attractive to pollinators and hummingbirds.
I would recommend placing lantana in full sun, and the good news is that it copes very well with drought and heat. What’s more, this species is not tolerant of excessively moist soil, so make sure it is well draining.
Lantana, as I mentioned, comes in many varieties and each one is suited to different types of gardening. For example, some species do well in hanging baskets, while others offer excellent ground cover. In any case, the leaves and berries of these plants can be toxic, especially when the berries are not ripe. If you have pets or children, this is a plant you’ll want to keep them away from.
You wouldn’t usually use lantana as a companion plant because it can become very invasive and sap your crops of their resources. Because of this invasive growth, it’s important to keep the plant under control with regular pruning. This will also encourage more bountiful flower production.
11. Lemon Grass (Cymbopogon citratus)
Lemon grass is a wonderful addition to a kitchen garden and is well known for its fresh, citrusy scent. It’s often used in East Asian cuisine, as well as in herbal teas and aromatherapy where it’s said to help relieve stress and anxiety. The plant is also valued for its aesthetic, grassy appearance.
Like several of the other plants on this list, lemon grass contains citronella, which is highly repulsive to many insect species, including gnats and mosquitoes which can be problematic to humans in summer as well as many fly species. For this reason, lemon grass is a good choice of companion plant for peppers and tomatoes as well as in your herb garden.
Lemon grass grows well as an annual plant in zones 9 to 11, and while it does tolerate partial shade, it’ll thrive best in full sun. Lemon grass is tolerant of various types of soil, although it prefers sandy soil that’s rich in nitrogen. You can grow lemongrass in a container and make cuttings to expand your collection.
When harvesting lemongrass, be sure to collect the lower part of the stalk and allow the upper part to carry on growing.
12. Cosmos (Cosmos)
Unlike most of the other plants on this list, cosmo doesn’t produce any chemicals that repel insects. However, it does have a very strong aroma that may deter some pests from coming near it. What’s more, the brightly colored flowers are attractive to pollinators and will even draw the attention of parasitic wasps, which will control pest populations in the garden.
While there are around 30 varieties of cosmos, only three of these are commonly used in the garden. They can be planted as a companion for various vegetables and sunflowers as well as in a herb garden.
The great thing about cosmos is that they can be grown in many places and are hardy in zones 2 to 11. They prefer a sunny position and must be planted in well-draining soil. But one of the great benefits of these plants is that they’re low maintenance and very easy to care for. Once established, these plants will remain for many years in the garden, bringing a pop of color from summer right up until the first frost. Note that these plants must be grown from seed, and these can be planted right after the last frost.
Cosmos are a popular choice of cut flowers to include in bouquets and come in a huge range of colors, depending on the variety, which include white, pink, yellow, and red.
13. Ageratum (Ageratum)
Ageratum refers to between 40 and 60 species of plants that thrive in tropical and warm climates. These plants produce a natural compound known as coumarin which creates a very unique scent that insects seem to hate. This works for common garden pests like whiteflies and aphids and makes ageratum a good companion for peppers, cabbage, and tomatoes.
While typically thriving in warmer climates, ageratum does grow well in most USDA zones, typically between 2 and 11. For the best flower production, be sure to deadhead regularly and make sure that the plant is placed in a sunny spot, although it can tolerate a small amount of shade. Most ageratum flowers grow in fluffy clusters and are some shade of blue but there are varieties that may have pink or white blooms. In any case, they’re a great choice of cut flowers.
You can purchase ageratum seeds or grow from a young plant and once it is established, this is a very low maintenance species. What’s more, it’s ideal for smaller gardens as it doesn’t grow very big and remains compact.
Tips & Advice for Growing Pest-Repelling Plants
Using chemicals to repel pests in the garden is incredibly damaging to the environment. Not to mention the harm it does to beneficial creatures like bees, birds, and other pollinators. So, choosing natural pest control methods like plants is a great option. If you’re new to growing pest-repelling plants, here are my top tips.
1. Create Protective Barriers
Before you start planting anything, take a look around your garden and identify any problem areas for pests. These are the areas you’ll want to place a heavy focus on.
What’s more, it’s a great idea to plant several pest-repelling species at the entry points of your garden and around the borders. This will serve as a barrier to pests trying to get in.
However, you need to be careful not to cram these areas with plants in the hopes of greater effectiveness. Once the plants start growing, they may start to crowd one another and this will result in a lack of airflow which could result in fungal diseases.
2. Strengthen Pest Protection by Using Companion Planting
Pest-repelling plants will do a good job wherever they are placed in the garden. But they offer the best support for your plants and crops when they’re paired with vulnerable species.
For example, many repelling plants offer protection to vegetables and fruits like cabbage, tomatoes, and cucumber. Sage and rosemary work very well next to cabbage, while basil is a great companion for tomatoes. The use of marigolds around tomatoes is also common owing to this plant’s ability to deter nematodes. Parsley and thyme work very well as companion plants for potatoes.
You can also include trap plants among your repellers, which are designed to lure pests away from your crop species.
Using companion plants is one of the best methods of natural pest control and it’s a great way to add aesthetic value to your garden.
3. Grow a Diverse Array of Pest-Repelling Plants
If you’re looking to make your garden as repelling as possible to pests then only planting one species of plant isn’t going to have the desired effect. The greater the diversity within your garden, the more pests will be deterred.
You’ll want to consider your local climate and choose species that are adapted to this, otherwise they’ll struggle to grow and may lose effectiveness. Moreover, consider your USDA growing zone and opt for plants that thrive best in these zones.
Plants grow at varying heights, and it’s a good idea to include several heights as this will help to deter pests at every level. Remember that some pests fly while others remain on the ground. You can plant your chosen species in different areas of the garden, such as along pathways and borders. If you’re growing taller species, using things like fences and trellis for support can be useful.
That said, while you do want a good range of plant species, you need to be careful not to go overboard and crowd your garden. Too many plants means that individuals will have to compete for resources. What’s more, crowded plants can create a humid microclimate among the foliage, which is highly attractive to pests.
With this in mind, I would recommend looking at the growth habits of any potential species you’d like to include. While you may buy a small plant, some species have rapid and wide growth, which can quickly take over an area. Mint is a good example of this. While you can grow it, you will need to stay on top of pruning.
Also consider that plants thrive in different seasons. If you want to maximize your gardens pest-repelling abilities then be sure to choose a variety of plants that will deter pests throughout the seasons.
4. Ensure Regular Plant Care & Maintenance
In the wild, plants pretty much take care of themselves but in the garden, it’s your job to give them a helping hand. This means regular maintenance and care, including things like providing the plant with sufficient water. Different species have varying water requirements, so it’s important to understand this first. However, it’s essential not to go over the top and give your plants more water than they need as this can stress the plant, cause disease, and even attract more pests.
Pruning your plants regularly is a fantastic way to encourage the production and release of their pest-repelling compounds. Again, the species will depend on how often pruning needs to be done but typically, this is done after the plant flowers.
Plants will only grow healthily if they have good soil, so I’d always recommend using an organic mulch to boost nutrients within the soil. Mulch will also help to suppress weeds so your plants won’t have to compete for resources.
The health of the soil also depends on good drainage so, before planting, be sure to turn and aerate the soil. Keep in mind that different plants have different needs when it comes to soil composition, so check this before selecting plants. You can adjust the pH of the soil according to your plants needs; add lime to make it more alkaline or compost to increase the acidity.
Pay close attention to your plants to stay on top of their health. Early detection of things like pests and diseases gives you the best chance of treating them effectively.
5. Grow Plants that Attract Beneficial Insects
As well as deterring pests, many of the plants I have discussed in this guide serve as a way of attracting beneficial wildlife.
This often includes pollinators like bees and butterflies, which will help to pollinate the crops and plants in your garden, keeping it healthy. What’s more, some of these plants help to attract predatory insects like ladybugs and wasps that will feed on pests and act as another natural barrier against them.
Your plants will also attract birds and other wildlife to your garden because of the habitat they create. Hummingbirds are attracted to a lot of the plants on this list and they’re not only beautiful to observe but also act as pollinators for around 8000 plant species in the Americas.
6. Don’t be Scared to Experiment & Refine
When you first start growing pest-repelling plants, it may require some trial and error, and that’s OK. Some plants may do better than others in your climate and the garden conditions, so it’s really important to pay close attention to your garden.
Make sure to regularly inspect the effect of the plants and how they have impacted pest activity. If you find that the plants you initially selected aren’t performing as expected, there’s no harm in switching things up.
You may also find that certain combinations work better than others which is why it’s a good idea to try pairing different plants and experimenting with the results.
One thing I would highly recommend is documenting your results in a gardening journal. This will more easily allow you to track changes and make adjustments where necessary.