I have heard quite a bit about the claim that certain plants repel flies and mosquitoes in the garden. There is no shortage of this information on the internet.
The fact is that I have had several of the recommended plants in my garden and on my balcony in containers, not as repellents, but simply because I like those plants. I love fragrant plants like marigolds, lavender and basil among others.
I also have had more than my fair share of flies and mosquitoes and other flying insects in my gardens too. I also have tried different natural bug sprays too to repel flies.
I still understand there are some velum flying insects that are not so fun to have about, because they are annoying and some also can damage things.
I use cedar balls and dried lavender flower sachets to deter clothing moths from my stored winter woolens and sweaters in my closet.
Still, I was curious about those other plants being suggested to repel flies and mosquitoes as well.
So decided to do some research and find out about the idea about repelling plants, specifically for flies and mosquitoes in the garden. I in turn found information that I would like to share.
Can Plants Really Repel Flies? The Science Behind It
The Myth Of Fly Repellent Plants
You can find lots of sources online of plants that are supposed to repel flies in your garden. Many of them don’t say what kind of flies they are talking about when they say “flies” (unless they specifically say “mosquitoes”).
As a result, it’s hard to know for sure. The word “flies” seems to be used as a sort of catch-all for nearly any insect that has wings, except mosquitoes or stinging insects like bees and wasps.
The reasoning behind it is that these plants that these plants have very aromatic foliage and insects are not fond of those smells and will avoid the plant.
Therefore, just planting them in your garden keeps away the flies and other unwanted visitors.
The Reality Of Fly Repellent Plants
As I delved deeper beyond plant lists, a different narrative emerged.
Bountiful studies exist on repelling insects mosquitos, tse-tse flies that transmit human disease, etc. The use of plants to deter insect pests from stored grain, flour, and wool textiles has a body of study.
What most studies have in common is that they rely on extracted essential oils from the plant to develop concentrated insect repellants or fumigants for a smaller, more enclosed area.
Other approaches to studies in the field are based on hanging fresh plant material, using dry leaves, and/or burning fresh or dried plant materials such as leaves and bark and creating an aromatic, insect-repelling smoke.
What stood out from my readings is that the use of plants to deter insects is far more nuanced than that. It is more than growing the lampranthus plants in a garden or placing the repellent plants in a living space.
In fact, growing certain species of repelling plants in your own garden may not grant you immunity to flies or mosquitoes.
I would suggest applying these plants in heavy foot traffic and well-used outdoor areas, or casual sit spots, like patios, near a deck around yards, etc.
How Mosquito And Fly Repellent Plants Work
Studies have indicated that specific plants are known to contain compounds that can repel insects, but only in controlled environments, such as in a laboratory or an enclosed environment.
There have been many studies of plants-or more exactly extracts of plants-to repel or kill insects, especially biting insects like mosquitoes or ticks.
Much of the research has looked at using concentrated plant essential oils-for use in products we call “insect repellents”-to put on our skin.
The basic idea behind many of the repellents is that the strong scent masks the smell that attracts the insect pests. It is not that they necessarily do not like the scent-it’s just that it is masking the smell they are searching for.
For instance, mosquitoes are attracted to the scent of our skin and the CO2 when we exhale.
So when we apply some of the insect repellent to our skin, the volatile chemicals evaporate and produce a very thin chemical vapor layer over our skin. (That’s the scent we smell.)
This vapor layer essentially masks the smell of our skin and makes it more difficult for the insect to find us. Eventually, all of the oils will evaporate and stop producing an effective barrier, which is why insect repellents need to be applied every so often.
Recent research on insect repellents also discusses how certain scent(s) also interfere with the sensory processes (or sense of smell) of the insects which may also prevent those insects (mosquitoes or ticks) from finding a host (our bare skin)!
After reading a number of the studies mentioned above, it seems fair to say that for the scent of the plant to work, the scent needs to somehow be released or concentrated. In other words, simply having the plant in your garden will not create a deterrent.
According to North Carolina State University, there is no scientific basis of using garden plants to control the insects around a deck or patio.
The Bottom Line
Apparently, there is no scientific evidence supporting the use of plants around the deck or patio to catalyze the idea of repelling flies or mosquitos.
That said, there are a plethora of other effective fly control strategies for mosquitos that you can use.
These strategies solidify more on controlling the reproduction cycles of mosquitos to help reduce their numbers in your garden.
But of course, there is no harm in including some of the plants usually evidence suggested in association with deterring flies, especially when many of them are ornamental.
Some also emit a pleasant, mild scent when brush past them and even after it rains! Personally, I enjoy lavender and rosemary.
So it’s not a problem to include some attractive plants in your garden or in groupings around a patio.
Even if there is no scientific evidence to support using some plants for repelling flies from your garden, you get soothing aromatherapy out of it!
Enjoy Aromatherapy & Test The Theory of Plants That Repel Flies and Mosquitoes
If you’re interested in testing the hypothesis of the power of garden plants to repel flies and mosquitos, while experiencing the process of garden aromatherapy, thenhere are some fragrant plants you may want to consider:
- Containers: Plant fragrant plants in large containers at your door so you can brush the foliage and release their fragrance as you walk by.
- Border Plants: Plant a low hedge of fragrant plants on the edge of a deck or patio to create a scent barrier.
- Fragrant Posies & Bundles: Grow fragrant plants and cut them to hang in doorways or inside.
- Essential Oils & Sprays: Add to the potency of your insect repellent plants by also using other fragrant sprays in bowls of potpourri (but not to your skin).
Companion Planting And Fly Repellent Gardens
There are plenty of beneficial insects to have in your garden! Like: hoverflies (each are also called syrphid flies or flower flies), lacewings, and parasitic wasps to help control aphids.
Then there are tachinid flies that control an entire realm of pests, including cabbage worms, cucumber beetles and corn ear worms.
So as gardeners, it is an added bonus when these flies stop by your garden, especially in the vegetable sea.
Many beneficial insects – those that help control common garden pests like aphids and whitefly – have a striking resemblance to insects we would not welcome into our gardens.
For example, hover flies appear to be small leathery jackets (wasps) and then the tachinid flies might be mistaken for house flies.
Before you swat the flies circling close to you, think about all the good that they could be providing in your garden!
While it is not a foregone conclusion that plants can help repel flies and mosquitoes, they can attract beneficial insects. So it is valuable to think about your garden as an ecosystem overall.
For example, lavender and marigolds (that are frequently suggested to deter flies and mosquitos) also promotes beneficial pollinators and insects in your garden that help to control pests effectively.
These types of plants are wonderful for both ornamental garden beds as well as patios. Areas where you want to benefit from natural fly or mosquito control, while enjoying your plant displays.
If you want to gain natural control of aphids or other garden pests, it is great to include some of these plants in your vegetable beds.
Top Plants With Fragrant Foliage
Deep on some level, we will only enjoy observing and smelling a few plants if we can touch them all the time.
When wrapping the aromatic plants around the decks and patios they look and smell great when the breeze gently blows through the leaves. Even better if they actually are some of the best plants for repelling flies paras around patios!
Try putting containers of lavender, rosemary, or citronella near the seating areas for a little aromatherapy and hopefully natural insect control! Here are a few of the most fragrant ones:
1. Lavender
Lavender is found in many forms, including English (Lavandula angustifolia) and Spanish (Lavandula stoechas). The English lavenders have the most fragrant flowers and foliage.
The flower heads are made of many tiny flowers creating a spike at the top of the stem. When the flowers begin to show color but has not fully opened, the spike can be cut and made into a bunch to dry indoors.
| Scientific Name | Lavandula angustifolia |
| USDA Hardiness zone | 5-10 |
| Type | Evergreen perennial |
| Mature Size | 1-3 feet (30 – 90 centimeters) depending on variety |
| Sun Exposure | Full sun |
| Soil Type | Well-draining |
| Watering Needs | Water deeply when soil dries out. Drought tolerant once established. |
2. French Marigolds
Various types of marigolds exist. French marigolds, meanwhile, have multiple tiny flowers that are either double or semi-double in form and come in the colors: red, orange, or yellow. They have bushy growth habit and their fern-like leaves are aromatic.
French marigolds are yet another plant you can grow to attract hoverflies, which are beneficial insects, to your garden.
| Scientific Name | Tagetes patula |
| USDA Hardiness zone | 2-11 |
| Type | Annual |
| Mature Size | 6-12 inches (15-30 centimeters) tall |
| Sun Exposure | Full sun |
| Soil Type | Moist well-draining |
| Watering Needs | Allow soil to dry between waterings, then water deeply |
3. Tansy
Tansy is a lovely flowering plant, but it is highly self-seeding and is listed as invasive in many areas. Be sure to check with your local invasive plant community before attempting to put it in the ground:
Tansy has soft, ferny leaves. The leaves also have a very pungent odor that not everyone likes. It has small yellow button-like flowers in late summer. As with any self-seeder, you will want to dead-head the blossoms before they go to seed.
Otherwise, your garden will soon be taken over by the vigorous tansy plant and will spread to nearby garden beds.
Note: The plant is toxic to humans, pets, and livestock.
| Scientific Name | Tanacetum vulgare |
| USDA Hardiness zone | 3-8 |
| Type | Perennial |
| Mature Size | 3-4 feet (90-120 centimeters) tall |
| Sun Exposure | Full sun |
| Soil Type | Not fussy about soil type |
| Watering Needs | Drought tolerant once established |
4. Mint
Mint is available in a couple varieties, and all have their distinct fresh fragrance when the leaves are crushed. Many will know that a mint plant will have a square stem and when rolled between your fingers, you can feel the corners.
Mint plants can spread unchecked through underground runners, taking over the space in your garden. For this reason, many people will try to contain the plant by planting it in a larger container, or giving it a dedicated raised bed area.
| Scientific Name | Mentha spp |
| USDA Hardiness zone | 3-11 |
| Type | Perennial herb |
| Mature Size | 1-3 feet (30 – 90 centimeters) tall, depending on variety |
| Sun Exposure | Full sun to part sun |
| Soil Type | Moist well-drained |
| Watering Needs | Keep plants evenly moist. Tolerant of occasional drought |
5. Rosemary
This evergreen herb resembles lavender and is a beautiful plant. Rosemary has gray-green triangular thick needle-like leaves growing upright on woody stems.
In early summer, it will bear clusters of small light purple-blue flowers. Many people grow rosemary in containers and bring it inside to overwinter because it does not have cold tolerance.
| Scientific Name | Salvia rosemarinus sp |
| USDA Hardiness zone | 8-10 |
| Type | Evergreen perennial herb |
| Mature Size | 2-6 feet (60-180 centimeters) depending on variety |
| Sun Exposure | Full sun |
| Soil Type | Well-draining |
| Watering Needs | Drought tolerant once established. |
6. Sage
The sage family is very large and diverse and includes the culinary herb, as well as numerous ornamental flowering varieties.
Not all salvias are edible, but they all have the characteristic strongly aromatic foliage. The edible culinary sage is Salvia officinalis.
There are several culinary sage cultivars that have foliage in shades of cream and pink (Salvia officinalis ‘Tricolor’) or bright yellow (Salvia officinalis ‘Aurea’).
| Scientific Name | Salvia officianalis |
| USDA Hardiness zone | 4-10 |
| Type | Perennial |
| Mature Size | 2-3 feet (60-90 centimeters) tall, depending on variety |
| Sun Exposure | Full sun |
| Soil Type | Well-draining |
| Watering Needs | Drought tolerant once established |
7. Basil
Basil is a well-known herb that shares the same plant family with mint. Like mint plants, basil has a square stem. There are many different varieties of basil and they are all edible.
The leaves are highly aromatic and become fragrant with just a sniff. Although basil is associated mostly with Italian cuisine, it is native to India.
Once the plants start to flower, the leaves will become bitter, so if you want to use basil for cooking, you will want to pinch back the growing tips once the plant is around 8 inches (17 centimeters) tall in order to promote continued leafy growth and not flowering.
| Scientific Name | Ocimum basilicum |
| USDA Hardiness zone | 10-11 |
| Type | Annual |
| Mature Size | 18-24 inches(45-60 centimeters) tall depending on variety |
| Sun Exposure | Full sun |
| Soil Type | well-draining |
| Watering Needs | Keep soil evenly moist |
8. Bay Laurel
Bay laurel is an evergreen species, and can grown as a shrub or small tree. The dried leaves are what commonly appear on the grocery store shelf, labeled as bay leaves in the herbs and spices section.
Bay trees are not cold hardy, so in many areas they are container grown and brought indoors for the winter. They are also fast growers, which requires repotting every spring.
| Scientific Name | Laurus nobilis |
| USDA Hardiness zone | 8-10 |
| Type | Evergreen perennial |
| Mature Size | 10-60 feet (5-30 meters) |
| Sun Exposure | Full to part sun |
| Soil Type | Moist well-drained |
| Watering Needs | Keep soil evenly moist |
9. Eucalyptus (Silver dollar tree)
Eucalyptus is most widely known for being the food of the koala bear in its original home, Australia. The tallest Eucalyptus species can grow to almost 60 feet (20 meters) in its native habitat.
Silver dollar eucalyptus has silvery gray-green leaves with a strong penetrating smell reminiscent of menthol, mint, or pine trees.
The leaves of the plant, when young, are round discs and hug the stem at the base (which is how the plant received its common name). As the plant grows, the leaves become elongated, narrow, and pointed.
Silver dollar eucalyptus will not tolerate a lot of cold, so it is often planted in a pot and moved indoors over the winter months. It can also be grown indoors as a houseplant.
Be mindful that eucalyptus leaves are toxic to both people and pets.
| Scientific Name | Eucalyptus cinerea |
| USDA Hardiness zone | 8-10 |
| Type | Annual orPerennial; evergreen or herbaceous |
| Mature Size | Up to 40 feet (13 meters) |
| Sun Exposure | Full sun |
| Soil Type | Well-drained |
| Watering Needs | Drought tolerant once established |
10. Citronella
We are all familiar with citronella candles for repelling mosquitos, and citronella oil is sold for that reason too. It may be hard to tell if it is all just hype, or if they actually work, but they certainly have pleasant fragrances!
There are two plants that have the characteristic scent of citronella. The real citronella plant is actually a grass, either Cymbopogon nardus, or Cymbopogon winterianus; the other is a scented geranium, the citronella geranium (Pelargonium citrosum).
Both plants have the same strong lemony scent in the foliage, but the oils that produce that scent are probably not present in high enough concentrations to repel insects.
Citronella grass is a clumping perennial grass that is hardy in USDA zones 10-12 but will be grown as an annual in colder zones. It can grow up to 2 meters (6 feet) tall and 1.3 meters (4 feet) wide, and is grown for the concentrated oil in citronella products such as candles.
The citronella geranium (or lemon geranium) is a more useful garden or houseplant. It can be grown in a pot, or in a garden bed. The geranium has bulbous deeply-lobed leaves, and makes a small pink flower.
NOTE: Citronella geranium is highly toxic to cats and dogs, and brushing the foliage, or having a carnivore near the foliage, may cause dermatitis. Additionally, some people may experience skin rashes from brushing the foliage.
| Scientific Name | Pelargonium citrosum |
| USDA Hardiness zone | 9-11 |
| Type | Perennial often grown as an annual |
| Mature Size | 2-3 feet tall (60-90 centimeters) |
| Sun Exposure | Full sun to part shade |
| Soil Type | Well-draining |
| Watering Needs | Can tolerate short periods of drought. Prefers to be kept evenly moist |
11. Sweet Woodruff (Sweet-scented Bedstraw)
Sweet woodruff is a creeping ground-cover plant, with long narrow leaves that grow in “whorls” (growing around the other around the same growth node) along the stem. It has small white star flowers in spring.
Sweet woodruff spreads by underground rhizomes, so it will form a dense groundcover. It is sometimes considered invasive.
When crushed, the foliage gives off a nice sweet scent, and it gets stronger when the foliage is dried. It used to be a stuffing in mattresses and pillows in its native Europe.
There is also a compound in the leaves called coumarin that has been known to help in keeping moths and mosquitos at bay.
| Scientific Name | Galium odoratum |
| USDA Hardiness zone | 4-8 |
| Type | Perennial, evergreen in warmer zones |
| Mature Size | 6-8 inches (15-20 centimeters) tall |
| Sun Exposure | Part to full shade |
| Soil Type | Well-draining |
| Watering Needs | Needs consistent moisture |
12. Chrysanthemum
Chrysanthemums are available in a variety of forms, one of which is affectionately called garden mums. Some flowers resemble tiny buttons or pompoms, and other flowerheads contain numerous long spidery petals.
They bloom in fall with colors that appear in burgundy, bronzy orange, yellow, pink, light purple, and white.
The flower of the chrysanthemum has a chemical called pyrethrin that is toxic to many insects. It is isolated from the chrysanthemum flower to make commercial insecticidal products.
| Scientific Name | Chrysanthemum x morifolium |
| USDA Hardiness zone | 5-9 |
| Type | Perennial |
| Mature Size | Up to 3 feet (90 centimeters) tall, depending on variety |
| Sun Exposure | Full sun |
| Soil Type | Moist well-draining |
| Watering Needs | Keep evenly moist |