Biodegradable Non-woven Grow Bags DO NOT Biodegrade

A couple years ago, I wanted to give away seedlings without breaking the bank giving away their pots too. I searched online for a cheap container solution, and thought I'd struck gold finding biodegradable non-woven grow bags. You can buy loads of these for next-to-nothing on eBay. They claim to be biodegradable, so healthy for the environment. Excellent, or so I thought. Sigh... They are anything but...

Biodegradable non-woven grow bags

I decided to do a bit of an experiment with them the same way this guy did on YouTube.

I filled them with potting soil, and planted some cherry tomato seeds in them. The seedlings germinated nicely. When their roots began growing through the bottoms of the bags, I thought this is great. I planted them directly into their final 30 litre pots for the greenhouse conveniently leaving them in the grow bags. No need to risk sending the seedlings into shock through transplanting. I assumed the biodegradable bags would simply decompose amongst the roots as the plants grew.

This assumption appeared to work according to plan. The tomato plants did wonderfully well growing to full size and producing a profusion of sweet tasty tomatoes for weeks on end. Yum!

My disappointment began when I cleared out the spent soil from the pots at the end of the season. Like 'Farmer G', with his sunflower plants in the video above, I found the grow bags still fully intact with tomato roots growing through them. The bags had not even remotely broken down.

I found this rather unsettling, but I thought I would give the manufacturers the benefit of the doubt. These grow bags are specifically advertised as 'Biodegradable' after all. To continue the experiment, I threw them in the compost bin, feeling optimistic I would never see them again.

I was wrong. 

Yesterday, while harvesting some rich black beautiful compost to mix up some soil for this year's vegetables, I stumbled across some unexpected items. You guessed it, the grow bags! I could not believe my eyes.

Biodegradable non-woven grow bags

I pulled them out for closer examination. I tugged at them. They did not tear. I looking at them. They still possessed their original non-woven texture. I turned them round and round. Except for some discolouration, they were still usable. Literally, no evidence of breakdown whatsoever.

Horrified, I did some Googling. It turns out, these grow bags are made of polypropylene, a plastic. This is not biodegradable. I don't have a clue how so many suppliers get away with such blatant false advertising.

It suffices to say, I will never use them again.


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