Getting rid of bugs in outdoor potted plants can be challenging, but is definitely achievable with some knowledge and effort. Here are the most effective methods for ridding your outdoor container gardens of common insect pests.
Inspect Plants Frequently
The first step is prevention – inspect your plants at least once a week during growing season. Check under leaves, along stems, and in the soil for any signs of bugs. Early detection makes controlling pests much easier.
Look for things like:
- Chewed or deformed leaves
- White blobs on leaves or stems (eggs)
- Small worms or crawling insects
- Webs spun between leaves or stems
Catching pests early allows you to take action before they multiply and cause major damage.
Remove Infested Parts of Plants
If you spot just a few bugs clustered on one area of a plant, prune off and discard those parts. For example, cut off leaves or stems with lots of aphids on them. Or dig out areas of soil containing larvae.
This removal limits the spread of the infestation. Just be sure to sterilize your pruners between each cut with rubbing alcohol to avoid transferring pests.
Use Neem Oil
Neem oil is a natural pesticide that smothers and kills many species of soft-bodied insects. It won’t harm beneficial species like ladybugs or earthworms.
Mix neem oil with water according to package directions. Put the solution in a spray bottle and coat all surfaces of plant leaves, stems, buds, and even soil. The oil’s residual effects can help deter pests for up to three weeks.
Apply Insecticidal Soap
Insecticidal soap is another organic treatment that kills mites, aphids, and other small soft-bodied bugs by dissolving their exoskeletons. Like neem oil, it doesn’t affect helpful insects.
Spray plants thoroughly with insecticidal soap, especially under leaves. Repeat weekly as needed until pests are gone. This soap works on contact and doesn’t have residual effects.
Sprinkle Diatomaceous Earth
Diatomaceous earth (DE) is a powder made from fossilized algae that cuts into insects’ bodies, causing dehydration and death. DE is non-toxic to mammals and plants, and helps control ants, beetles, mites, and more.
Sprinkle a light layer of DE over soil and use a paintbrush to dust leaves. Reapply after rain or watering. Wear a mask when using to avoid breathing in the dust.
Set Out Sticky Traps
Yellow and blue sticky traps lure in aphids, whiteflies, leafhoppers, and other small bugs. Place these traps near plants around the edge of containers. Check traps weekly and replace as they fill up with insects.
Traps alone won’t fully control pests, but help monitor which bugs are present and active so you know if other methods are working.
Use Row Covers
Row covers are fabric sheets that let in sunlight and rain but keep out many flying insects with a barrier. Drape these over plants infested by Japanese beetles, cabbage moths, potato beetles, and other pests that attack from the air.
Secure the edges of row covers with rocks, garden staples, or stakes. Remove periodically to thin and harvest plants.
Introduce Beneficial Insects
Some bugs like ladybugs, lacewings, and predatory mites feed on plant pests. You can buy populations of these beneficials to release into your container garden. They’ll naturally kill and eat target pest species.
Follow instructions when introducing beneficials so they stay and thrive. Provide nectar sources like flowering plants. Their numbers will grow and attack pests all season.
Apply Bacillus thuringiensis
Bt is a natural bacteria that kills leaf-eating caterpillars like cabbage loopers when they ingest it, but is safe for other species. It comes in liquid concentrates, powders, or granules.
Apply Bt to leaves where you see caterpillar damage. It must be reapplied after rain. Once caterpillars stop feeding, they’ll die within a few days.
Use Horticultural Oil Sprays
Horticultural oils suffocate soft-bodied pests like mites, aphids, mealybugs, and scale on contact. They also deter feeding. Unlike neem oil, they provide no residual effects.
Spray plants, including stems, undersides of leaves, and soil, thoroughly with horticultural oil. Repeat weekly until pests are gone. Do not apply to water-stressed plants.
Apply Insecticidal Bait Stations
Insecticidal baits draw in pests like ants with a tasty formula, then kill them after consumption. The worker ants take the poison back to the nest to kill larvae and queens.
Place small bait stations filled with boric acid around outdoor containers. Keep them sheltered from rain and sprinklers. Replace monthly until ant trails stop.
Control Weeds Around Containers
Weeds growing around the outside of containers can harbor pests like spider mites. Keep the area around your pots free of weeds. It helps reduce hiding spots and food sources for plant bugs.
Pull weeds by hand or use an organic herbicide. Place a layer of mulch around pots to prevent future weeds and retain moisture. Prevent seeds from germinating.
Use a Systemic Insecticide
Systemic insecticides are absorbed into plants and make their tissues and fluids toxic to chewing and sucking insects. They provide about 1-2 months protection.
Apply a systemic product like imidacloprid around the root zone of plants. It will be taken up by the roots. Avoid applying to blooming plants visited by pollinators.
Practice Crop Rotation
Rotating plants to a different container each year helps disrupt the life cycles of pests. Different plants are susceptible to different bugs.
For example, move tomato plants infested by hornworms last year into a new pot. Occupy the old tomato pot with cucumbers or carrots this season.
Clean Up Infested Garden Debris
Many pests overwinter in plant debris left in the garden. Remove all dead leaves, stems, roots, and other plant parts from containers and dispose of them.
Clean up fallen leaves and debris between pots. Removing this material gets rid of eggs and pupae deposited on last year’s plants.
Use Floating Row Covers in Ponds
Floating row covers help limit access of small flying insects to water garden pots. They rest right on the water’s surface to create a protective barrier.
Secure the edges with weights like bricks or stones. Make sure floating covers don’t block too much sun from reaching plants below the surface.
Add Fish to Water Features
Fish like goldfish or koi will happily eat mosquito larvae in outdoor water gardens and pots. They also feed on other young aquatic insects.
Research species suitable for your climate and container size. Provide adequate oxygenation and filters to maintain ideal water quality.
Use Mosquito Dunks Against Larvae
Mosquito dunks contain a biological larvicide that kills young mosquitoes but is safe for people, pets, fish and plants. The active ingredient (Bt) only impacts mosquito larvae.
Simply toss a mosquito dunk into water gardens or pots. The slow-release formulation lasts for 30 days or longer to prevent new generations of mosquitoes from hatching.
Maintain Good Growing Conditions
Healthy, vigorous plants are less vulnerable to major pest outbreaks. Make sure containers offer good light, airflow, drainage, and nutrition to support optimal growth.
Strong plants can better outcompete and recover from moderate pest damage. Address issues like compacted soil, drought stress, or nutrient deficiencies.
Know When to Start Over
Sometimes pest infestations get completely out of control. At a certain point, it’s easier to discard badly infested plants and start over fresh.
If more than 30% of a plant’s tissues are affected, removal is typically better than treatment. Severely infested pots can be impossible to remedy.
Conclusion
Controlling insect pests in outdoor pots requires diligence and persistence. Combining preventative measures, frequent monitoring, and targeted organic treatments offers the best control. Always start with lower impact options first before resorting to broad spectrum insecticides. A proactive, integrated pest management approach leads to the most successful and eco-friendly results in combatting unwanted bugs.
Frequently Asked Questions
How do I identify bugs on my outdoor plants?
Take a sample of the insect to your local nursery or extension office for expert identification. Or search online bug identification guides that allow you to match photos and descriptions. Proper ID is essential for finding the right control methods.
How often should I apply insecticidal soap or neem oil?
Insecticidal soaps and neem oils work on contact, so repeat applications every 5-7 days for a few weeks until pests are under control. Some products offer residual activity up to 3 weeks, but hand spraying often misses some insects so multiple applications improve control.
What plants attract beneficial insects?
Beneficial insects feed on nectar as adults. Good companion plants to attract them include members of the daisy family like coneflowers, asters, and rudbeckia. Also try umbelliferous plants like dill, fennel, and parsley or herbs like thyme, mint, and oregano.
Should I treat my potted plants before bringing them indoors for winter?
Yes, it’s wise to treat houseplants with insecticidal soap or neem oil before bringing them into your living space. An ounce of prevention avoids introducing pests to your indoor collection or home. Monitor closely for a few weeks after moving them inside.
How can I prevent insect pests in container gardens?
Choose resistant plant varieties, use row covers to keep out pests, apply beneficial nematodes to soil, maintain good growing conditions, rotate plants to different pots, remove weeds/debris, and introduce beneficial insects which prey on pests.
Will insecticides harm pollinators visiting my potted plants?
Some insecticides like neem oil and insecticidal soaps can harm bees and other pollinators. Only apply these to plants not currently in bloom. Avoid spraying any insecticides directly onto open flowers in your containers where pollinators may be foraging.