Plants That Repel Gnats

If you’re tired of tiny gnats buzzing around your face and plants, you need plants that repel gnats. This natural solution can help you reclaim your space without harsh chemicals.

It’s a simple, beautiful way to handle the problem. Let’s look at how it works and which plants do the job best.

Certain plants produce strong scents or oils that gnats and other insects find unpleasant. These aromas mask the smells that attract them or simply drive them away. By placing these plants in key areas, you create a living barrier.

This method is safe for pets, children, and your garden’s ecosystem. You get a double benefit: fewer pests and more greenery.

How Do Plants Repel Insects?

These plants contain natural compounds like citronellal, pyrethrum, or linalool. These are essences that insects avoid. They’re part of the plants defense system.

When you brush against the plant or the wind blows, these oils get released into the air. This creates a protective zone around the plant and its immediate area.

It’s important to manage your expectations. A single potted plant won’t clear a whole backyard. But strategic use in clusters or at entry points makes a real difference.

Top Plants to Keep Gnats Away

Here are the most effective plants for gnat control. Consider your climate and sunlight when choosing.

1. Lemon Balm

This member of the mint family has a strong lemon scent that gnats dislike. It’s very easy to grow, sometimes too easy—it can spread quickly in gardens.

Best For: Patios, window boxes, near doorways.
Care: Prefers full sun to partial shade. Water when soil feels dry.
Tip: Crush a few leaves between your fingers to release more scent when you’re sitting outside.

2. Lavender

Its beautiful purple flowers and calming scent are loved by people, not by gnats. The essential oils in lavender are a powerful deterrent.

Best For: Planting along walkways, in garden borders, or in sunny pots by seating areas.
Care: Needs full sun and well-drained soil. Avoid overwatering.
Tip: You can dry the flowers and make sachets for indoor use.

3. Citronella Grass (The Mosquito Plant)

This is the source of citronella oil, common in outdoor candles. Its grassy clumps have a distinct, sharp fragrance.

Best For: Large pots on decks or near outdoor gathering spots.
Care: Thrives in full sun and needs regular watering. It’s not frost-tolerant.
Tip: This plant is different from scented geraniums sometimes sold as “mosquito plants.” Look for the botanical name Cymbopogon nardus.

4. Marigolds

These cheerful flowers contain pyrethrum, a compound used in many natural insect repellents. They repel gnats and can deter other garden pests like nematodes.

Best For: Edging vegetable gardens, placing in pots around the patio.
Care: Love full sun. They are annuals in most zones but are easy to grow from seed.
Tip: French marigolds (Tagetes patula) are often considered the most effective.

5. Rosemary

This woody herb’s pungent smell is great for cooking and bad for gnats. It can be shaped into attractive bushes or topiaries.

Best For: Herb gardens, sunny borders, or containers.
Care: Requires full sun and excellent drainage. It’s drought-tolerant once established.
Tip: You can clip sprigs and place them on outdoor tables for extra protection during meals.

6. Catnip

Studies show catnip can be even more effective than DEET for some insects. The active ingredient, nepetalactone, is a strong gnat repellent.

Best For: Areas where you don’t mind cats visiting (they love it). Plant it away from garden beds you want to protect from feline attention.
Care: Grows easily in sun or partial shade. It can spread, so containment in a pot is often wise.

7. Basil

The strong aroma of basil, especially varieties like lemon basil or cinnamon basil, confuses and repels gnats. It’s a perfect dual-purpose plant.

Best For: Kitchen gardens, pots near outdoor kitchens or dining sets.
Care: Needs warm temperatures, full sun, and consistent watering. Pinch off flower heads to encourage leaf growth.

8. Pennyroyal

This is a potent member of the mint family. Its scent is highly offensive to gnats and fleas. A word of caution: it can be toxic to pets if ingested in large quantities.

Best For: Planting in pots (to control spread) in high-traffic gnat areas.
Care: Prefers moist soil and partial shade. Handle with care, as the oils can irritate skin for some people.

Where to Place Your Gnat-Repelling Plants

Location is key for success. You need to interrupt the gnat’s path.

Entry Points: Frame doorways, windows, and screen porches with pots. This blocks the routes gnats use to come inside.
Seating Areas: Cluster pots around your patio table, lounge chairs, or deck. Create a scented fortress where you relax.
Problem Zones: Place plants near compost bins, rain barrels, or damp corners where gnats might breed.
Indoor Use: Small pots of basil, lavender, or lemon balm on kitchen windowsills can help with fungus gnats from houseplants.

Maximizing the Repellent Effect

To get the most from your plants, you need to encourage the release of their oils.

Gentle Disturbance: Lightly brush or ruffle the leaves as you walk by. This is like hitting a “refresh” button on the scent.
Strategic Pruning: Regular harvesting of herbs like basil and rosemary promotes bushier growth and releases scent.
Crush Leaves: Before an outdoor gathering, gently crush a few leaves of lemon balm, mint, or basil to boost the aroma in the air.
Create Plant Groupings: Don’t scatter single plants. Group several of the same repellent plant together to create a stronger scent zone.

Other Natural Strategies to Combine with Plants

For a serious infestation, use these plants as part of a broader plan. Here’s what else you can do.

Eliminate Breeding Sites

Gnats need moisture to reproduce. Take away their nurseries.

Avoid overwatering houseplants and garden soil. Let the top inch dry out.
Remove standing water in saucers, buckets, or clogged gutters.
Keep compost bins covered and well-maintained.
Clean up fallen fruit and decaying plant matter quickly.

Use Natural Traps

Reduce adult gnat populations with simple traps.

Apple Cider Vinegar Trap: Fill a jar with a few inches of apple cider vinegar, a drop of dish soap, and cover with plastic wrap poked with small holes. Gnats go in but can’t get out.
Red Wine Trap: Leftover red wine works similarly to vinegar. They’re attracted to the fermentation scent.
Sticky Traps: Yellow sticky stakes near affected plants catch many adults.

Introduce Beneficial Predators

For fungus gnats in potted plants, beneficial nematodes or Bacillus thuringiensis israelensis (Bti) applied to the soil can target larvae without harming your plants.

Caring for Your Repellent Plants

Healthy plants produce more of the essential oils you need. Follow these general tips.

Sunlight: Most of these plants require plenty of sun (6-8 hours). Check specific needs.
Soil: Good drainage is crucial. Use quality potting mix for containers and amend garden soil if it’s heavy clay.
Watering: Water deeply but less frequently to encourage strong roots. Always check soil moisture first.
Feeding: Use a balanced, organic fertilizer during the growing season. Avoid over-fertilizing, which can lead to weak, sappy growth.

Common Mistakes to Avoid

A few errors can limit your success. Watch out for these.

Wrong Plant, Wrong Place: Putting a sun-loving lavender in a shady corner will result in a weak plant with low oil production.
Overcrowding: Plants need air circulation to stay healthy and prevent fungal diseases which can attract more pests.
Neglecting Other Sources: If you have a indoor plant with soggy soil breeding gnats, your outdoor repellent plants won’t solve the indoor problem.
Expecting Instant Perfection: This is a management strategy, not an instant eradication. It works best over time and as a preventative.

FAQ: Plants That Repel Gnats

What is the most effective plant for repelling gnats?

Lemon balm and catnip are often cited as the strongest due to their potent oils. However, the “most effective” plant is the one that thrives in your specific conditions, as a healthy plant produces more repellent oils.

Can I use these plants to repel gnats indoors?

Yes. Potted basil, lavender, or lemon balm on a sunny windowsill can help, especially with fungus gnats. Ensure the plants get enough light and that you aren’t overwatering your other houseplants, which is the real attractant.

How many plants do I need to see a difference?

It depends on the area. For a small patio, 3-5 sizable pots placed around the perimeter should create a noticeable effect. For larger yards, focus on protecting specific zones like seating or dining areas.

Do I need to crush the leaves for them to work?

Not necessarily. Brushing against them or the wind moving them releases scent. But crushing leaves intentionally gives a temporary, concentrated boost which is useful before you spend time outside.

Will these plants also repel mosquitoes?

Many of them do, as mosquitoes are also repelled by strong herbal scents. Citronella grass, lavender, marigolds, and rosemary are all known to help with mosquitoes too. Its a great bonus benefit.

Are gnat repellent plants safe for pets?

Most are safe, but always check. For example, lemon balm and basil are fine, but pennyroyal can be toxic if ingested by cats or dogs. If your pet likes to chew plants, choose pet-safe options and place others out of reach.

Why are gnats still here after I planted repellents?

First, check for breeding sites you may have missed. Second, the plants need time to establish and fill out. Third, if the infestation was severe, combine plants with traps to reduce the current population. The plants will then help prevent new ones.

Using plants that repel gnats is a smart, sustainable way to enjoy your garden with fewer pests. It connects you to natural solutions and adds beauty and fragrance to your space. Start with a few pots of lavender or basil near your back door, and observe the difference. With a little patience and the right plant placements, you can significantly reduce those pesky insects and create a more pleasant outdoor environment for everyone.