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Nov 06, 2024

Discover Grow Bags: An Alternative Plant Container | Almanac.com

Topping up potatoes with compost growing in a space-saving vegetable grow bag. Variety ‘Charlotte’ is a waxy salad potato which thrives in containers. Become a better gardener! Discover our new

Topping up potatoes with compost growing in a space-saving vegetable grow bag. Variety ‘Charlotte’ is a waxy salad potato which thrives in containers.

Become a better gardener! Discover our new Almanac Garden Planner features for 2024. It’s easy, fun, and free to try!

If, like me, you resort to using containers to grow some of your plants, try using a grow bag this year. They have some advantages over plastic pots or terra cotta. I was especially interested to learn about “air pruning.” Here’s why and when to use a grow bag and some different types of grow bags.

Grow bags aren’t a new idea. In ancient times, plants were grown in woven baskets and bags. Ancient Egyptians would weave plant baskets and the Greeks used woven containers on their rooftop gardens because they could be easily moved. Many British gardeners have long grow bags as an alternative to planting directly into greenhouse soil.

Today, they are still ideal for growing plants in the greenhouse, but there has been growing interest in using them as an alternative container.

Grow bags are are especially helpful and affordable for growing plants on patios and balconies!

Pots are heavy and difficult to move. Grow bags are lightweight. If you are growing on your balcony or anywhere weight is an issue or will need to move the containers during the growing season, fabric pots weigh practically nothing. It is only the weight of the soil that you have to deal with.

They are breathable and drain well. Unlike plastic, the fabric allows air to reach plant roots so the soil won’t get soggy. It is hard to overwater them.

They prevent plants from becoming rootbound. When a root reaches the side of the container it comes in contact with drier soil and more air. Instead of circling the pot and eventually strangling the plant, that root stops growing. Called “air pruning,” this encourages the plant to make new roots giving it a robust root system with many small root tips that can take in water and nutrients instead of a few long roots choking it. The plant can put more energy into top growth as well. Many growers swear that the plants in the grow bags do much better than those in plastic pots.

Soil is cooler in summer. Black plastic pots heat up in the summer sun. Since the bags can breathe, heat can escape. The felt-like fabric is more insulating than plastic so the soil stays a bit warmer when the weather cools down.

Grow bags are best for vegetables that do not have deep roots. My favorites include:

You’ll plant 2 to 3 plants in a bag in the spring. For salad greens it’s best to cut across the width of the bag and sow in rows.

See our Almanac Grow Guides for information on planting all of the above vegetables.

Be mindful when shopping online for grow bags that all bags are not the same. There are some really cheap ones that are just heavy-duty, black plastic bags—like a contractor’s trash bag. They might be cheap but they offer none of the advantages of a fabric grow bag. Plastic bags do not water well; they retain water and heat which is bad for the soil!

A good grow bag is are constructed from a polypropylene felt-like fabric which is breathable and allows the air pruning. The fabric must be BPA-free and food-safe.

Here are some examples of quality grow bags. (We do not get any payment from Gardener’s Supply Company. We just like their grow bags!)

Gardeners.com Tomato Grow Bags

Gardeners.com Potato Grow Bag

There are many sizes to choose from ranging from small seedling bags to 1,000 gallon raised garden beds. There are specialty grow bags like the 15 gallon potato bag that has a flap near the bottom so you can easily harvest new potatoes without disturbing the whole plant. There are tall skinny ones made for growing trees. You can get square ones to make an instant planting bed. A 4’X4’ square 12 inches deep holds 16 cu ft. or 120 gallons of soil. There are small ones, 4”X5”, with Velcro closures to make removing seedlings for transplanting easier.

I bought 2 at my local hardware store a few years ago just to try them out and use them every summer to hold extra plants. One year it was sweet potatoes, then pepperoncini, and last year tomatoes.

Handy folks can try making their own grow bags from heavy-duty landscape fabric. Be sure to use nylon thread instead of cotton which will deteriorate fast causing your bag to fall apart.

Got a balcony, patio, or rooftop garden? Seee more about growing plants on a sunny patio or balcony!

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Josie (not verified)

1 year 5 months ago

Are drainage holes needed on the bottom of a fabric grow bag? The grow bags I purchased do not have any drainage holes on the bottom.

Jennifer Keating

1 year 5 months ago

In reply to Are drainage holes needed on… by Josie (not verified)

Great question, Josie!

Typically grow bags are made of a pervious material that excess water will slowly drain from, therefore, drainage holes are typically not required in grow bags.

Mayur (not verified)

1 year 6 months ago

very well explained the topic, I am wondering if you had explored more on point no 5, it wud be more helpful ... Anyways I am loving your blog and blogs from https://www.grow2plant.com

Shobande olumuyiwa (not verified)

2 years 11 months ago

Good job, it's attractive and encouraging

Rhonda (not verified)

4 years 1 month ago

Will you please share where to get the round tomato/pepper cages shown in the pictures? Thank you!

The Editors

4 years 1 month ago

In reply to Cages on tomato grow bags by Rhonda (not verified)

The bags and cage in that image come from Gardener’s Supply Company.

sarah (not verified)

4 years 5 months ago

I started some seedlings indoors from seed and they need transplanted asap. I've settled on using grow bags, but how many cherry tomato plants can I plant in 3 gal or 5 gal?

Anna (not verified)

4 years 7 months ago

I might have missed this, but how many gallons is considered "all purpose" for grow bags? I want to grow some tomatoes, squash and peppers---3 gal? 5 gal?

Lisa (not verified)

4 years 7 months ago

I have been searching everywhere for a grow bag that is taller than it is wide to grow fruit trees, but everything I find is too shallow. Any suggestions? I don't want anything made in China or from recycled materials as I've seen lab test results from some of those bags and they are not good.Thanks!

Virginia (not verified)

5 years 7 months ago

I was wondering about using some of the decorative grocery bags that you can buy now to replace the plastic ones.-Some I have are similar to the fabric used in landscaping, and not at all like the shiny, tarp-like ones.Do you think they could be used for planting veggies? I am unsure of what they are made of..

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