Does Foil Around Plants Really Deter Pests? The Science Behind This Gardening Trick

You’ve probably used tin foil for many things, from wrapping baked potatoes to wrapping a holiday gift. Why not try wrapping plant stems in the garden as a means of pest protection? It’s an effective, inexpensive way to keep certain pests from garden favorites.

Wrapping plants in tinfoil is not the best known method of natural pest control, but it’s having a moment. After all, anything you can use to put a barrier between pests and plants can deter them. But the concept of wrapped plants is not without its downsides.

Read on for an honest “wrap up” of what you need to know about using tinfoil in the continuing battle against plant pests.

How to Use Foil for Pest Control

A gardener has to be creative these days when it comes to deterring plant pests. The recommended sprays can be toxic, fencing is impractical, and picking off bugs by hand is not an option for the squeamish.

Using tinfoil in the garden as a bug repelling plant collar is certainly a creative idea. It may not be a permanent solution but it’s certainly worth a try. The general idea is to wrap foil around the plant stems to keep bugs out.

Keeping Pests from Attaching Tender Stems

This gardening technique is used to protect tender plant stems from garden pests. The idea is to wrap 2-3 inch (5-7cm) strips of foil around the base of the main stem. The foil acts as a barrier against certain insect pests, like vine borers, cutworms, and squash bugs. You’ll need to start the foil just below the soil line.

The protection is versatile; it works in different ways on different bugs. A tinfoil wrap that starts in the soil will prevent moths from laying squash vine borer eggs on squash and cucumber stems. The same setup also stops cutworm larvae from using young stems as dinner, and prevents squash bugs from attacking the lower, softer parts of the plant. If you’d like to try this one, be careful not to wrap the foil so tightly it impedes growth.

Confusing Insects with Reflected Sunlight

I personally have never had squash bugs, vine borers or cutworms in the garden. My plants do seem to attract aphids however, as well as whiteflies. While these insects may be too small and mobile to be kept off plants by a ring around the base of the stem, the shiny side of the foil may also repel them.

If you wrap your plants with tinfoil and leave the shiny side out, it will reflect the sunlight. This reflected UV light confuses these insects, making it harder for winged aphids to find and feed on a plant. In fact, you don’t have to wrap plants at all to make this happen. If you cut strips of foil and hang them near the plant, you get the same effect. Some recommend adding strips of foil to your mulch.

Note that it’s not a good practice to wrap leaves, since they need sunlight. Likewise, you’ll have to remove the tinfoil when frost arrives; they create a home for fungus like powdery mildew. You should also be sure to not wet the stems of plants wrapped with foil for the same reason. Using a drip irrigation system like this one from Amazon will help keep all the moisture at soil level and reduce the chances of fungal infections.

Wall Out Slugs and Snails

Aluminum foil can also be used against slugs and snails. Now this one interests me, since both of these garden pests attack my plants both in California and in France. The idea is to create a slippery surface that stops slugs and snails in their tracks.

Both snails and slugs are ground insects, sliding along the soil to find plants to eat. If you wrap sheets of foil around the base of plants in your garden, you are installing a shiny, slippery surface that these creatures do not want to crawl on.

To create a barrier, place large strips of tinfoil on the soil around them and pin them in place with rocks. If you are planting in a raised bed, cover the walls in tinfoil to bar entry to snails and slugs. You can also protect potted plants by wrapping their containers in aluminum foil.

Downsides and Drawbacks

Using aluminum foil for garden pest control is not without issues. Generally, you should consider it a temporary solution since it requires daily maintenance (to make sure the foil remains in place) and creates non-biodegradable waste. Here are a few downsides to consider.

• If you wrap the foil too tightly, your plants may not be able to grow.
• Tightly wrapped foil can damage the bark and hold in moisture that leads to rot.
• Reflected light can cause leaf burn, especially as summer temperatures rise.
• The foil can scare off beneficial insects as well as the pests you want to deter.
• Wind, rain, and rodents can dislodge or tear the foil, requiring replacement.
• Determined insects may push their way through to your plants despite tinfoil.

If you are looking for a new, creative way to stop pests, give this foil trick a try. Just be sure to keep an eye on your plants to mitigate any problems that may arise. It is worth a shot!