Fabric grow bags have become more common over the last few years, and they have some key advantages over plastic pots. I’m writing this to break down the differences and help other container gardeners decide on what to use. I have used both, but I prefer grow bags and this is why:
Grow bags drain and dry more efficiently than plastic pots because the entire container is porous. This helps to prevent drowning your plants by overwatering. Well-drained containers have fewer issues with mold. I have noticed that root rot isn’t as common in grow bags as it is in plastic pots.
Plants need fresh oxygen near their roots to thrive. This is why plants in compacted clay-filled soil don’t grow well. Because grow bags are porous, they allow oxygen to flow into the soil from all angles. Solid plastic pots block airflow, preventing that much-needed oxygen from getting to the plant’s roots.
Better Temperature Control
Fabric grow bags don’t get as hot as plastic containers because of their breathable fabric. Living in Louisiana, I struggle with heat issues with some of my plants. Plastic pots trap heat. Imagine wearing a breathable cotton t-shirt compared to wearing a watertight rain jacket.
Grow bags fold flat and take up less room while in storage. This is especially helpful for people in small spaces who don’t have much room for storing gardening supplies. While pots have to be stacked a mile high, bags take up a tiny fraction of that same space. One cardboard box or storage container is all you need to keep a large number of grow bags.
Moving bigger plant containers can be difficult. The majority of grow bags contain built-in handles. The handles make it much easier to move large grow bags. Moving an equivalent sized traditional pot is harder because you can’t grip it as well as the bags.
Healthier Root Structure
The root structures of plants grown in fabric grow bags look much healthier than roots in plastic pots. This is due to something called air pruning. The reason this happens is that the roots can sense the air near the porous edges of the bags. In a solid container, the roots run into the wall and entangle themselves because no air is passing through. Check out this image from Root Pouch, a company who sells fabric grow bags:
The Downside to Grow Bags
The only downside to grow bags that I have noticed is specific to transplanting. The plant’s roots will eventually grow into the pores of the bag. When I transplant from a smaller bag to a bigger one, roots can get damaged because they are embedded in the fabric. The solution to this problem is to avoid transplanting by using larger bags. Some grow bags are made to biodegrade quickly, these can simply be buried in the ground without removing the container.