Alternatives to plant containers:grow bags
Which vegetables can be grown in bags？
If, like me, you resort to using containers to grow some plants, try using grow bags this year. They have some advantages over plastic pots or terracotta. I am particularly interested in understanding "air dressing". Here is why and when to use grow bags and some of the different types of grow bags.
are not a new concept. In ancient times, plants were grown in woven baskets and bags. Ancient Egyptians would weave plant baskets, while the Greeks used woven containers on their roof gardens because they could be moved easily. Many English gardeners have long used grow bags instead of planting directly in greenhouse soil.
Today, they are still perfect for growing plants in greenhouses, but there is growing interest in using them as alternative containers.
Grow bags are particularly useful for growing plants on patios and balconies and are inexpensive
-Pots are heavy and difficult to move. Grow bags are light. If you are growing plants on a balcony or anywhere where weight is an issue, or if you need to move containers during the growing season, then cloth pots weigh almost nothing. You only have to deal with the weight of the soil.
-They are breathable and drain well. Unlike plastic, fabric allows air to reach the roots of the plants, so the soil doesn't get wet. It's hard to flood them.
-They prevent plants from rooting. When the roots reach the side of the container, it will be in contact with dry soil and more air. The roots will not rotate around the pot, which will eventually kill the plant, but will stop growing. This is called "air pruning" and it encourages the plant to produce a new root system with many strong root tips that can absorb water and nutrients, rather than killing its long roots. The plant can also put more energy into its highest growth. Many growers swear that plants in grow bags are much better than plants in plastic pots.
-Cool soil in the summer. Black plastic pots can get hot in the summer sun. Because the bags can breathe, they can dissipate heat. Felt fabric is more insulating than plastic, so the soil will stay warm when the weather turns cold.
Best plants for grow bags
Grow bags are best for vegetables that do not have deep roots. Some of my favorites include
-Zucchini and summer squash
-Salad greens (lettuce, broccoli, rocket)
-Basil and some herbs
In spring, you will plant 2 to 3 plants in one bag. For salad greens, it is best to cut the width of the bag and sow the seeds in rows.
Choosing a grow bag
When buying grow bags
online, be aware that all bags are different. Some very inexpensive bags are like heavy-duty black plastic bags, just like contractor's garbage bags. They may be cheap, but they don't have the advantages of a fabric grow bag. Plastic bags do not water well; they retain moisture and heat, which is not good for the soil.
A good grow bag is made of polypropylene felt fabric that is breathable and can be trimmed of air. The fabric must be BPA-free and food safe.
Here are some examples of quality grow bags.
A variety of sizes are available, from small nursery bags to 1,000-gallon raised garden beds. There are special grow bags, such as the 15-gallon potato bag, that have baffles near the bottom so you can easily harvest new potatoes without disturbing the entire plant. There are also tall, thin bags for planting trees. You can purchase a square bag to make an instant planting bed. A 12" deep 4' X 4 square foot square can hold 16 cubic feet or 120 gallons of soil. There are also smaller 4" X 5" bags with Velcro closures that make transplanting seedlings even easier.
I bought two at the 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 peppers, and last year tomatoes.
-All plants grew well even though larger bags could have been used for the groundnuts. Many plants grow in an L-shape, as if they hit the side of the bag and then turn at right angles.
-The compost in the bag should not be too compact; make it loose like a pillow by shaking and kneading.
-Remember that the top of each root ball should be directly under the top of the bag.
-Water well and label. Keep the compost moist and apply a high potassium fertilizer to plants such as eggplant, tomatoes, cucumbers and peppers at bloom time.
-Because grow bags are porous and drain quickly, they do require more frequent watering than plastic containers. If using them indoors, be sure to place them on a large tray to control leaks.
-Taller plants (such as tomatoes) need support. Place the canes in the bag, tie the plants to the canes, and then secure the canes to the frame.
-Good bags are built to last! Many bag makers say they last 3 to 4 years, but after 3 growing seasons, my bag maker still looks new. I dump the soil into the compost in the fall, let the bags dry, then fold them up and store them for the winter. They are very sturdy and can be used for hauling wood, composting or mulching when they don't contain plants, or as harvest baskets.
Those with dexterity can try making their own grow bags from durable landscape fabrics. Be sure to use nylon thread instead of cotton, which can deteriorate quickly and cause the bags to break.