Grow bags are a useful alternative to plant pots, but they’re not all the same.
Depending on what the bag is made from, it will have different pros and cons. To make the right choice, you need to understand what types of grow bags there are and what makes them different from each other.
Here’s a rundown of the main types of grow bags.
Fabric Grow Bags
Most grow bags are made from some type of fabric, including homemade grow bags that are crafted from spare fabric scraps.
Fabric grow bags can be either woven or non-woven. This is an important distinction.
Non-woven bags allow water to drain freely, air to enter the soil, and heat to exit. These are all some of the biggest benefits of grow bags, but you only get them if you use non-woven fabric bags.
Woven fabrics retain more water, which can lead to overwatering and sometimes mold. Air also doesn’t enter the bag as easily, meaning you won’t get the same level of air pruning as you would with a non-woven bag.
Non-woven Grow Bags
The two main materials used for non-woven grow bags are polypropylene or felt.
Polypropylene is a fabric made from very thin strands of plastic. Instead of being sown together, these bags are either fused through heat or chemical bonds.
Although it’s a type of plastic, polypropylene bags are very breathable, lightweight, and durable. This is also the most recyclable type of plastic, so once your bag wears out you can wash it and recycle it fairly easily.
The other material that’s used for non-woven grow bags is felt. Felt is a fabric made from any thin threaded material that can be matted. Usually, it’s made from natural materials like wool or fur, but there’s also acrylic felt.
Felt is a very sturdy material that’s both breathable and durable. It can also be either heat sealed or chemically sealed instead of being sewn, reducing the number of seams.
Woven Grow Bags
Some other grow bags are made from woven fabrics. The most common woven fabric material is canvas, which you see most in handmade grow bags.
Canvas is very strong and long lasting. It can hold plants well season after season.
The problem with canvas and other woven fabric grow bags is that they don’t drain easily, and they don’t allow a lot of air in. This can lead to mold and overwatering. You may need to cut a few small drainage holes around the bag, which you don’t normally have to do with non-woven grow bags.
Related: How to Wash, Store, and Care for Grow Bags
Plastic Grow Bags
The cheapest types of grow bags are plastic grow bags. These are essentially the same as black garbage bags in different sizes. They’re most commonly used to line larger pots or to start seedlings for transplanting later on.
In general, it’s not a good idea to use plastic grow bags for long-term growing. They’re not durable, they retain heat, and they don’t drain water at all unless you add drainage holes.
If you need a lot of very small containers for seedings or other temporary growth, they can be a good option. Make sure you choose BPA-free bags, because they will not leach any harmful chemicals into the soil or the surrounding environment. Depending on what you’re planning to grow in your bags, this is going to be important.
Eco-friendly Grow Bags
Beyond the standard fabric and plastic grow bags, you can also find a range of eco-friendly alternatives. These are either made from recycled materials, recyclable materials, or biodegradable materials.
Recycled plastics are more eco-friendly than new plastics. Recyclable plastics are also better than non-recyclable plastics. However, they’re both not great for the environment.
The better eco-friendly option is natural, biodegradable material such as hemp or burlap. Both materials are strong enough to last for a while, but they are also fully biodegradable.
While hemp and burlap are good eco-friendly options, they do share some of the same problems as other woven fabric grow bags. The drainage isn’t ideal, leading to water retention and poor air circulation.
Also, since the bags are biodegradable, they can begin to break down slowly while they’re still in use, usually after a few seasons of use. The longer you use them consecutively, the faster they break down.
Final Thoughts
Grow bags are a great option for many different gardens. By choosing the right grow bag, you’re more likely to get better results for whatever you’re growing, without any unnecessary cost or effort.
