I've got three 10-gallon grow bags that I'm looking to sterilize before starting my fall planting. They previously held tomatoes, which unfortunately had spider mites, so I disposed of the plants. Now, I'm planning to grow snap peas and broccoli, but I want to make sure the potting mix is safe from those pesky spider mites. What are the best methods to effectively sterilize 30 gallons of potting mix?
3 Answers
One great method is solarization! After you remove the tomatoes, cover your grow bags with clear plastic sheeting. Just secure it down with some landscaping staples and let it sit in the sun for about a month. This will get the soil super hot, helping to kill off most pests and pathogens. It won’t be perfectly sterilized like in a lab, but it's a solid way to reduce harmful bugs and diseases!
You could try hydrogen peroxide too, but be cautious! While it’ll definitely kill all the pests, it also wipes out the beneficial microbes. You'll need to reintroduce those good microbes afterward because soil without them is pretty much just dirt. Just something to consider!
Just a heads up, sterilizing soil isn’t always the best move for your plants. It’s been known for a long time that plants benefit from the bacteria and fungi in the soil. Plus, spider mites come from outside, so even if you sterilize, they might still find their way back. Just something to keep in mind!