Does Bleach Kill Weeds? Yes, But Here's Why You Should Never Try It

Key Takeaways

• Bleach can kill weeds, but it can also change soil conditions (including raising pH) and leave salts behind—making it harder for desirable plants to grow.

• Don't use bleach as a weed killer. It isn't labeled for weed control, and using pesticides in ways not listed on the label can be illegal. Bleach runoff can also harm nearby plants and waterways.

• Better options include hand-pulling, mulching, growing dense plantings that shade out weeds, and using drip irrigation or soaker hoses to water only the plants you want.

Bleach is a common DIY weed killer that's often suggested in online home remedies for killing weeds . These DIY concoctions are touted as safer, more affordable, and more natural than commercially prepared herbicides, with advice to mix bleach with water and spray it on weeds until they're deader than a doornail. But given that bleach is a powerful chemical, is that really a good idea?

We asked an expert to weigh in on bleach as a weed killer. Long story short: Yes, bleach kills weeds, but that doesn't mean you should use bleach as a weed killer. "I cannot say this strongly enough: You should not use bleach to kill weeds," says Ralph Mitchell , director of the University of Florida Extension Office. "Keep bleach out of the garden and in the laundry room."

Meet Our Expert

Ralph Mitchellis the director of the University of Florida's Extension Office in Charlotte County, Florida, where he leads a comprehensive horticultural program.

Will Bleach Kill Weeds?

Bleach can damage and kill weeds because it's a strong chemical designed to disinfect. On contact, it can burn plant tissue—so you may see weeds turn brown and wilt.

But bleach isn't a selective weed killer. It can also harm nearby plants and soil life. And because it can move with water through soil, it may reach roots you didn't mean to affect.

Related: 37 Lawn and Garden Weeds: How to Identify and Control Them

Undesirable Side Effects on Soil

Here's the bigger issue: bleach doesn't just affect the weed you spray.

"Bleach hangs out in the soil longer than you want it to," Mitchell says. "It will kill weeds, but it can cause other damage to your garden."

Household bleach is alkaline, and repeated use can raise soil pH. Many garden plants struggle in overly alkaline soil because they can't take up nutrients as well. Bleach products can also add salts to the soil, which may stress or kill plants and make it harder for new plants to establish. In other words, you might solve a weed problem and create a soil problem at the same time.

Bleach can burn eyes and skin, so protective clothing such as gloves and safety glasses are recommended when handling it.

Is It Safe to Use Bleach on Patio Weeds?

You'll sometimes see bleach recommended to kill weeds that pop up in the cracks between pavers or along driveway seams. The thinking is that there's "no soil" to harm.

In reality, water moves. Rain or rinsing can carry bleach off hard surfaces and into nearby lawn or garden beds, where it can damage plants and affect soil. Runoff can also reach storm drains and waterways. Because bleach is harmful to aquatic life, it's not a good choice for outdoor weed control—especially anywhere water can wash it away.

Related: How to Make and Use a Vinegar Weed Killer

Read the Label

Mitchell also points to a practical (and legal) issue: only use products the way the label tells you to use them. Bleach isn't labeled as a weed killer . Products made to control weeds are labeled for that purpose and explain where you can use them, which plants they target, and how to apply them safely. "It has taken millions of dollars and lots of clinical trials to make sure that a weed killer works properly," Mitchell says. "That label is a legal document and a well-informed set of instructions. Pay attention to it."

Related: Here's What You Can (and Should Never) Clean with Bleach

Better Ways to Kill Weeds

If you want a natural alternative to commercial weed killers , skip bleach. These options are safer for your garden—and they work best when you use them consistently.

• Pull weeds by hand. Pull after a rain or watering, when the ground is soft, so you're more likely to get the roots. 

• After you weed, mulch, mulch, mulch . A thick layer helps block light so fewer weed seeds sprout. As a bonus, mulch helps hold moisture and improves soil as it breaks down.

• Grow plants close enough to shade the soil. "A patch of healthy plants growing almost shoulder to shoulder can shade out the weeds, so the weeds never have a chance of growing," Mitchell says.

• Use micro-irrigation (such as drip lines or soaker hoses) to direct water to the plants you want. "That way you are not watering weeds," Mitchell says.

Related: How to Install a DIY Irrigation System

Read the original article on Better Homes & Gardens