Grow bags are an effective solution for a lack of space, especially in urban gardens. But is the fabric they’re made from water-permeable? Or should you put holes in the bottom of a grow bag so your plants can drain?
You should put holes in the bottom of a grow bag if it’s made from fabric that isn’t water-permeable. For example, a grow bag made out of cotton canvas would definitely need drainage holes, but a grow bag made from a water-permeable fabric like felt doesn’t need holes to drain.
In this article, I’ll discuss why grow bags might need drainage holes, what grow bags are made from, and why they dry out faster. I’ll elaborate on how a grow bag’s color affects plants, where to place your grow bags, and whether they help plants grow. If this sounds interesting, let’s get started!
Do Grow Bags Need Drainage Holes?
Most gardeners know that plants that don’t drain adequately die. Their roots rot, which kills the plant. But is poking holes in your grow bags really necessary?
In most cases, grow bags don’t need drainage holes. They are mostly made from fabrics that are porous and allow water through, providing adequate drainage. However, if you buy a grow bag that differs from that norm, it will need drainage holes. It’s best to check the material that your grow bag is made from.
When you buy new grow bags, do a quick test with the hose to see if they drain quickly. This is a surefire way to determine whether they’re water-permeable. If they’re not, you can poke holes in the bottom with a knife or other cutting tool.
What Are Grow Bags Made From?
You may wonder what grow bags are made from that makes them so porous.
While some are made from a type of plastic, others are made from felt or other pressed fabrics. What your bag is made of, however, depends on where or who you brought it from. There is no universal standard for materials at this time.
Because the materials are different, they’re not all equally porous. For example, polypropylene differs greatly from felt. Therefore, it’s important to test your bags. You need to know what you’re dealing with before making a decision.
Some grow bags may be made of eco-friendly, biodegradable materials, whereas others might not.
If you’re wondering whether polypropylene will poison your plants, don’t worry. It’s food-safe, so plants grown in polypropylene grow bags are safe for human consumption. Even though plastic products are loosely associated with cancer in humans, the risk of polypropylene to your plants is minimal.
Do Grow Bags Dry Out Faster?
So, grow bags are porous and let water escape pretty easily. Do you need to watch out for your plants getting too dry?
Grow bags dry out faster than regular growing pots. They’re more exposed to the air, and the fabric allows air through into the roots, drying the soil faster. If you’re worried about your soil drying out, you can water it more frequently or choose one of the following methods to keep it moist:
- Drip irrigation systems. These are simply small nozzles you set on top of the soil near the base of your plant. Every time the timer goes off, the system releases some water into the soil to keep it moist. These systems excel when growing moisture-sensitive plants and are great for grow bags, too.
- Sprinkler systems. Another solution you can try is to set up a sprinkler system next to your grow bags. If you set your garden up a certain way, you can even water a raised bed or other gardening areas while watering your grow bags simultaneously.
- Mulching. Yet another thing you can do to help prevent your plants in grow bags from drying out is to apply mulch or shredded leaves on top of their soil. This helps hold the moisture in, suppresses weeds, and as these organic materials break down, they’ll leech more nutrients into the soil.
Does the Color of the Grow Bag Matter?
Now that we’ve talked about the fabrics grow bags are made from, you may be curious about whether their color matters.
The color of the grow bag matters, even more so if the grow bag’s walls are thin. Plants don’t enjoy having sunlight on their roots, and using a brightly colored bag can cause them to pull their roots away from the bag’s walls. A thick bag, however, makes this a moot point.
A plant’s roots are vulnerable. When a plant grows, it seeks to keep the roots underground, away from the sun and anything else that might damage them. If a plant’s roots encounter light, they might change course or even stop growing.
Should Grow Bags Be Placed on the Lawn?
So, plant roots are sensitive to the surrounding conditions. Does that mean they might not do well if you keep them in a grow bag on your deck?
Grow bags should be placed on the lawn. On a deck, concrete, or other hard surfaces, your plants will only get moisture from the weather and your watering. However, if you put them on your lawn, they’ll receive water from the ground, too.
Grow bags tend to leave stains, which is another reason why they should be put on the lawn. Dyes from the bag and dirt that escapes can leave a mess around where you placed your grow bags when you remove them, and it can be hard to clean up. However, you won’t have this problem if you keep your grow bags on the grass.
Do Plants Grow Differently in a Grow Bag?
If plants in grow bags flourish when placed on the lawn, does that mean they grow differently in grow bags, to begin with?
Plants grow differently in grow bags for two reasons:
- Firstly, the grow bag’s material allows for better airflow.
- The second reason is that the grow bag better allows them to sense the outside world, which means they’re less likely to become rootbound.
It’s common knowledge that plant roots need air, despite their desire to stay underground. This is why roots don’t grow well when their soil is too dense. Typically, soil contains small spaces called “pores,” which allow oxygen to permeate the ground, and without them, plants struggle.
As for the grow bags, they’re made of fabric. Being above ground, they let through a small amount of light and a good amount of air. This makes your plants better able to sense the confines of their enclosure. They’ll grow differently than they would in a plastic tub as a result and likely be healthier than their counterparts who are growing underground.
Can Any Plant Be Grown in a Grow Bag?
You may wonder whether grow bags are a suitable solution for all the plants in your garden.
Any plant can be grown in a grow bag. Nothing will hold you back other than the size of your grow bags, which come in many shapes and sizes. In fact, many plants, such as potatoes, tomatoes, and flowers, will flourish in them because of the airflow they provide.
As long as you can adequately water your plants, keep them stable, and provide enough room for them in the grow bag, there’s no reason to think you can’t grow anything you want in them. The sky’s the limit with grow bags, so don’t be afraid to experiment.
How Are Fabric Grow Bags Cleaned?
But what do you do with your grow bag when the growing season is over? Do you need to clean them, and if so, how do you do so?
Fabric grow bags are cleaned by scraping out the soil, vacuuming the grow bag, then handwashing them with detergent. If you’re interested in cleaning fabric grow bags, check out my article on the subject: How to Clean Fabric Grow Bags (Complete Guide)
Conclusion
Grow bags are made of felt or polypropylene and only need drainage holes if they don’t drain well. They generally have great ventilation and drainage, although this can cause your plants to dry out faster.
Any plant can be grown in a grow bag, and placing them on the lawn will help them grow better and healthier.
