How to Clean Grow Bags

There are a few different methods for cleaning & sterilizing your grow bags, fabric pots, and fabric grow beds after using them to get them safe and ready for another season. Choose whichever method below works best for you and suits your needs and available supplies.

I suggest shaking out your grow bags, and then washing as much dirt off as possible with a hose or pressure washer. Follow this up with a soap and warm water soak / agitation before finishing with a sterilization method below

How to Clean Grow Bags

A power washer is a GREAT way to remove all the stuck-on-dirt and mineral buildup on grow bags. This is the easiest way to clean grow bags if you've got a power washer.

I do not recommend machine-washing fabric grow bags, but if you do be sure to use a cold / gentle cycle with baking soda. Do not machine-dry.

Often, calcium and other minerals will build up on the grow bags. To combat this, you can use a mixture of vinegar, water, and baking soda. The vinegar will help to clean the bags and remove the mineral buildup. The baking soda will help with funky smells and stains, and fizz up to help loosen caked dirt and minerals.

How to Sterilize Grow Bags

It's important to sterilize / sanitize your grow bags to kill off any lingering bacterial / fungal remnants which could cause problems with your next grow cycle.

Bleach

Dilute 2tbsp (tablespoons) bleach per gallon of water. That's about 7.4mL per Liter. Consider wearing clothes you don't mind splashing bleach on. Turn fans on, and open the windows if working inside with bleach - the harsh fumes can be dangerous in confined spaces!

Benefits

• Inexpensive
• You probably already have some under your sink

Downsides

• Will stain your clothes
• Fumes are very harsh, don't forget to open all the windows!

Vinegar

Vinegar does not kill 99.99% of germs, and is therefore not a viable disinfectant on its own.

Vinegar does not kill viruses and does not effectively eliminate all dangerous bacteria.

That said, it will kill a large swath of the bacterial and fungal spectrum.

More important is vinegar's use as a descaling agent for removing hard mineral buildup. For our use case with grow bags, vinegar is not used as a primary sterilizing agent, but as a descaler with supplemental antimicrobial properties.

You can use white vinegar 1:1 with water, or you can also use full strength vinegar. Submerge your grow bags and let them soak for 20-30 minutes in vinegar before washing in plain water.

You can also use this as a spray and apply it to every surface of the bags before washing.

It should be easy to wash mineral buildup off shortly after applying a vinegar solution. Continue to apply and rinse until you've eliminated most of the mineral buildup your grow bags may have.

Hydrogen Peroxide

The go-to for sterilizing grow bags, fabric pots, cell packs, and fabric planters.

Mix 2 parts water to 1 part H2O2 and use as a soak or a spray

Boiling

Don't do this. People sometimes suggest it, but use warm soapy water instead. Boiling water can disintegrate the fibers of the bags, especially if they're not a nylon weave bag.

Sunlight / UV

While UV from the sun can be very effective in eliminating bacteria and fungi, UV will not eliminate all viruses.

Additionally, it's often difficult to hit every part of a grow bag with direct sunlight. You'll have to turn them inside out and rotate them often to make sure they're hit with an adequate amount of sunlight to kill some microbes.

Because of these difficulties and shortcomings in UV sunlight sterilization, I'd recommend using this as a supplemental sterilization method whose primary purpose could just be drying to bags after washing and sterilizing.

Put the bags out in the sun to dry if you're in a hot sunny climate, and you'll get the added benefit of a bit of UV sterilization along with dry bags.

If you're in a cool climate, the sun is likely just not hot enough to have much of any real UV sterilization effect.

Final Thoughts...

Be sure to let your grow bags completely dry out before putting them away for the season. If you'll be using them for planting right away, you can leave 'em wet and get to planting.

I don't recommended putting fabric bags or fabric planters in a dryer for this, you could easily scorch them. Rather, a good air-dry (preferably in the sun) is the go-to move.

Happy planting!