The idea for tomato bags came from across the Pond. For years, gardeners in England have made the most of very limited garden space by growing tomatoes directly in bags of compost, potting soil, or topsoil. They lay the bags flat, cut slits, insert tomato plants, and voila! Instant tomato containers.
Alas, the biggest problem with growing tomatoes this way is soil depth. These bags are only a couple of inches deep when laid flat. But tomatoes have wide and long root systems. Without good anchoring they sprawl everywhere and die off quickly. Shallow-rooted plants like lettuce, spinach, and beans are better suited to growing in regular bags of soil from the garden center.
Another issue with growing tomatoes like the Brits do – in bags of topsoil or potting soil – is the flimsy plastic. Plus tomatoes planted in potting soil bags are hard to water.
But it sure is a convenient idea – growing tomatoes in bags. So enterprising gardening manufacturers built on the concept. They developed some cool grow bags just for growing tomatoes. (There are other grow bags just for other kinds of veggies, too.)
Won’t tomato grow bags rip?
Right now the best tomato bags are available through Gardener's Supply
and www.amazon.comPlanters). These bags are made of double-layer polypropylene instead of sheet plastic. It’s the kind of material used in landscaping – strong and durable. Reinforced seams and stitched corners make them last longer, too. With care you can get several seasons out of them.
What about watering tomato grow bags?
As any container gardener may know (or soon discovers), tomatoes in containers need to be watered often – daily as the season progresses and plants mature. On the other hand, regular watering leaches nutrients from the pots. So watering container tomatoes can be tricky.
The fabric used to construct these particular tomato grow bags is like felt. It breathes. This means excess moisture has a place to go: out. The felt-like fabric allows water to move through the soil and carry nutrients to the plant. But then water exits. Plants don’t choke and drown in built-up water. They won’t suffer from over-watering or heat build-up. Good aeration helps prevent root rot.
The fabric helps roots in another way. The texture allows "root pruning" of the plants. That means the roots grow to the edge of the bag. Then, instead of circling around and around and getting root-bound (which is what happens in most containers), the fabric “air-prunes” the roots. Roots get to the edge of the bag and stop. Plants sprout newer roots elsewhere along the tap. So the root system in tomato bags grows healthier and stronger.
The bottom line
Tomato bags – if you choose the high-quality version like these – work really, really well for growing tomatoes. Bags made of flimsy plastic will give weaker results.
These two kinds of tomato bags, which are the best when it comes to quality, are available in two sizes. (Remember: when it comes to growing tomatoes in containers, the bigger the pot, the better.)