How to Use Flour in the Garden to Deter Pests, Boost Plant Growth, and More

Flour is a kitchen staple, but it's also surprisingly useful in the garden. If applied correctly, this multipurpose ingredient can deter pests, enrich compost, and even enhance soil health. It's also a more affordable (and natural) solution, as most people will likely already have some extra flour on hand at home.

Here, we've broken down exactly how to use it on your plants—and all the things it can do.

Deter Garden Pests

Flour can be used to deter pests like aphids, cabbage worms, and beetles.

“Simply dust a light layer over leaves in the morning when plants are slightly damp from dew,” says Sara Rubens, certified garden coach and founder of Seed to Sanctuary. The flour will cling to pests and can gum up their mouthparts, making it harder for them to feed.

However, while this method is effective, she advises against heavy application, as it may attract ants or mold if the weather is wet.

Suppress Weeds

Flour can act as a natural weed killer. All you have to do is mix a small amount with salt and sprinkle the combination directly into the cracks in your concrete or between pavers.

“The fine particles of the flour help the salt stick and penetrate weed roots more effectively," says Rubens. However, don’t go overboard and use this mixture on every crack you see. “The mixture can harm nearby garden plants if it spreads,” she warns.

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Enrich Compost

Most common types of flour, including wheat, almond, buckwheat, and coconut, can be composted.

“They're made from plant-based materials, meaning they break down well in a compost pile and are a part of the brown waste, since they’re rich in carbon,” says Angelika Zaber, a lawn care specialist and gardening expert at Online Turf.

Just don't add too much flour to your compost all at once, as this may attract rodents, she warns. “Instead, add small amounts at a time, and then mix it well.”

Fertilize Your Plants

Flour is rich in nitrogen, which is beneficial for plant growth and supports the growth of beneficial microbes. If your soil is lacking this essential nutrient, sprinkling flour on the ground can act as a great amendment.

“[Don't] use too much at once, though,” Zaber warns. Garden pests will see the flour as food and may invade your garden. Instead, simply dust a small amount over the area that you want to fertilize, and mix the flour into the soil. Then water the location well.

Identify the Wind's Direction

If you're applying treatments like organic sprays or fertilizers, then flour can help you determine the way the wind is blowing. This is especially important if you're growing delicate plants, as it will keep the spray from floating toward them.

Simply toss a small pinch into the air and watch where it drifts, says Rubens. However, she only recommends using this method if the wind is calm. Blistery days can lead to the flour spraying all over your yard—and even yourself.