Hydrogen Peroxide in the Garden: Uses for Plants, Pots and Tools

Because hydrogen peroxide breaks down into water and oxygen, many gardeners and houseplant growers use it in diluted form. Here are popular uses, with dilution rates based on 3% strength.

Cleaning pots, trays and propagators

Old pots can carry over moulds and pests. Wash off soil, then soak or spray with 3% peroxide, leave for 10 minutes and rinse. Let everything dry before reuse.

Cleaning pruning tools

Wipe secateurs and blades with 3% peroxide between plants to avoid carrying sap and debris from one plant to the next. Dry the tools afterwards to prevent rust.

Refreshing waterlogged compost

Some houseplant growers water overwatered plants with a dilute mix, roughly 1 part 3% peroxide to 4 parts water, to add oxygen around the roots. Always fix the cause too: improve drainage, reduce watering and repot if the roots are rotten.

Seed soaking

Some growers briefly soak seeds (for about 10–20 minutes) in 1 part 3% peroxide to 4 parts water before sowing, then rinse. Results vary between seed types, so test on a small batch.

Hydroponics and reservoirs

Some hydroponic growers use peroxide to keep reservoirs clean. Follow your nutrient manufacturer's guidance, as peroxide can interact with some nutrients.

Important

• Always dilute, because stronger solutions can damage roots and leaves
• Test on one plant before treating many
• Do not use it in ponds with fish or wildlife
• Wear gloves when handling 6%
• Store sealed and out of reach of children and pets

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