If you’ve noticed a trail of ants marching up your favorite rose bush or swarming your vegetable patch, you’re probably wondering how to stop ants eating plants. While ants themselves aren’t always the direct problem, their presence can signal and worsen other issues in your garden. This guide will walk you through natural, effective methods to manage them without harming your plants or the environment.
Ants are often attracted to plants because of other pests, like aphids and scale insects, which produce a sweet substance called honeydew. The ants farm these pests for this food, protecting them from predators and allowing infestations to grow. So, controlling ants often means tackling a two-part problem. Let’s look at why they’re there and the simple, natural steps you can take.
How to Stop Ants Eating Plants
The key is to disrupt the ant’s cycle. You don’t necessarily need to eradicate every ant—they can aerate soil and help with decomposition. The goal is to stop them from harming your plants by breaking their relationship with sap-sucking pests and making your garden less inviting.
Why Ants Are on Your Plants
First, it’s helpful to understand what draws them in. Ants on plants are usually a symptom, not the cause. Here are the main reasons:
* Honeydew Harvest: This is the biggest attractant. Aphids, mealybugs, whiteflies, and scale insects excrete honeydew. Ants “milk” these insects and will fiercely guard them.
* Nesting Sites: Potted plants and raised beds with loose, dry soil can be perfect spots for ants to build nests, disturbing roots.
* Food Sources: Sometimes, they are foraging for plant nectar, seeds, or even bits of decaying matter caught on the plant.
* Protection: Some ant species will prune away competing vegetation or attack herbivores to protect a food source, like extrafloral nectaries on peonies or citrus.
Natural Deterrents and Barriers
Creating a physical or scent barrier is a great first line of defense. These methods make it difficult or unpleasant for ants to reach your plants.
Diatomaceous Earth (Food Grade): This fine powder is made from fossilized algae. It feels soft to us but is sharp on a microscopic level, damaging the waxy coating on insects’ exoskeletons, causing them to dehydrate. It’s harmless to mammals.
* How to use: Sprinkle a thick, unbroken ring of DE around the base of affected plants and around garden beds. Reapply after rain or heavy watering.
Natural Powders and Substances: Many common kitchen items can deter ants.
* Cinnamon: Ants dislike crossing strong scents. Ground cinnamon or cinnamon oil can disrupt their scent trails.
* Coffee Grounds: Used coffee grounds sprinkled around plants can mask scent trails and may deter ants.
* Chalk or Baby Powder: Talc-based powders can temporarily block ants. Draw a line with chalk or sprinkle powder around pots.
Sticky Barriers: These trap ants and prevent them from climbing.
* Horticultural Glue Bands: Wrap a band of sticky tape or specially made glue around tree trunks or the stems of larger plants. This stops ants from reaching the canopy where pests live.
Water Moats: For potted plants, this is very effective.
* How to do it: Place the potted plant in a slightly larger saucer or tray. Fill the outer tray with water, creating a moat the ants cannot cross. Ensure the pot’s drainage holes aren’t submerged.
Eliminating the Real Target: Aphids and Scale
Cut off the ants’ food supply, and they’ll often leave. Controlling honeydew-producing pests is crucial.
Manual Removal:
* For light infestations, spray plants with a strong jet of water from your hose to knock aphids off.
* Wipe scale insects off stems and leaves with a cotton swab dipped in rubbing alcohol.
Natural Spray Recipes:
* Soap Spray: Mix 1-2 teaspoons of mild liquid Castile soap (not detergent) with 1 quart of warm water. Spray directly onto the pests, coating them thoroughly. The soap breaks down their protective layer. Apply in the early morning or evening, and rinse plants after a few hours.
* Neem Oil Solution: Neem oil is a natural insecticide that disrupts pests’ life cycles. Mix as directed on the bottle (usually 1-2 teaspoons per quart of water with a little soap as an emulsifier). Spray all plant surfaces, especially the undersides of leaves, every 7-10 days.
Encourage Beneficial Insects: Invite nature’s pest control into your garden.
* Plant flowers like dill, fennel, and yarrow to attract ladybugs, lacewings, and hoverflies, which are voracious aphid eaters.
Disrupting Nests and Trails
If ants have built a nest in your pot or bed, you need to encourage them to relocate.
For Nests in Pots:
1. Remove the plant from the pot carefully.
2. Submerge the entire root ball in a bucket of water mixed with a mild soap solution for 15-20 minutes. This will flood the nest.
3. Gently rinse the roots with clean water and repot in fresh, clean soil.
Boiling Water: For nests in soil away from plant roots (like in pavement cracks near beds), carefully pouring boiling water into the nest entrance can be effective. This needs to be repeated and used with caution to avoid damaging nearby plants.
Vinegar Solution: A mix of equal parts white vinegar and water can wipe out scent trails. Spray it on paths, around pot rims, and on surfaces where you see ants. The scent dissipates quickly for us but is disruptive to them. Avoid spraying directly on plant foliage as the acidity can harm leaves.
Long-Term Garden Management
Prevention is always easier than cure. A healthy garden is more resilient.
* Regular Inspection: Check your plants weekly, especially the undersides of leaves and new growth, for early signs of aphids or scale.
* Avoid Over-Fertilizing: Excessive nitrogen fertilizer promotes the soft, sappy new growth that aphids love. Use fertilizers judiciously.
* Keep Plants Healthy: A stressed plant is more susceptible to pests. Ensure proper watering, sunlight, and spacing for good air circulation.
* Clean Up: Remove fallen fruit, decaying plant matter, and weeds where pests can hide.
What Not to Do
Some common advice can backfire or harm your garden.
* Don’t use borax or boric acid sugar baits directly in garden beds. They can be attractive to pets and beneficial insects.
* Avoid using harsh chemical pesticides. They often kill the beneficial insects that would naturally control your pest problem, creating a worse cycle.
* Don’t ignore the problem. A small aphid colony can explode quickly with ants as their bodyguards.
FAQ: Natural Ant Control in Gardens
Q: Are ants always bad for my plants?
A: Not always. They can help aerate soil and clean up decaying matter. The problem starts when they farm honeydew-producing pests, which weakens your plants.
Q: What is the fastest natural way to get rid of ants on my plants?
A: A combination is fastest. First, spray aphids or scale with a soapy water spray to remove the food source. Then, apply a barrier like diatomaceous earth around the plant base to disrupt ant trails.
Q: Will cinnamon or coffee grounds hurt my plants or soil?
A: Cinnamon is generally safe and may have mild antifungal properties. Used coffee grounds are best used sparingly; while they add organic matter, to much can temporarily affect soil acidity. It’s best to compost them first.
Q: How do I keep ants out of my potted plants for good?
A: Use a water moat for indoor pots. For outdoor pots, ensure they are not touching walls or other plants that provide a bridge. Regularly check for pests and keep the pot and surrounding area clean of debris.
Q: I got rid of the aphids, but the ants are still there. Why?
A: The ants may have a nest nearby or be foraging for other reasons. Now that the honeydew is gone, continue with deterrent barriers. They should move on once the food source is consistently absent and trails are disrupted. Patience is key.
Managing ants naturally is about observation and consistent, gentle intervention. By understanding their relationship with pests and using these barrier and deterrent methods, you can protect your plants effectively. Remember, the goal isn’t a totally ant-free garden, but a balanced one where they aren’t causing harm. Start with the simplest methods, like soap spray for aphids and a line of diatomaceous earth, and you’ll likely see a big improvement without resorting to harsh chemicals. Your garden’s ecosystem will thank you for it.