We often get asked this question when folks are selecting their Root Pouch grow bags for their houseplants, shrubs and trees.
A common myth is that plants will grow larger if potted in a larger pot, like a goldfish in a fishbowl. This seems logical, but actually most plants prefer a snugger fit. Roots do not quickly fill a space when given room, but rather grow when and where they want to, usually rather slowly.
When you repot into a much larger container, the roots are surrounded by soil and can’t pull the water from it fast enough, leaving it wet too long and drowning the roots. A smaller amount of soil dries out more quickly and allows more oxygen to reach the roots, which they need to survive. Of course, if you use a Waterpot Olla or Waterpot Spike (for narrower pots where Ollas may not fit) in the pot, over-watering will never be an issue !
Some potted plants might be better off staying a certain size for aesthetic or space saving reasons. A tip to save having to completely repot really large plants every year is to loosen the top third of the potting mix, simply scrape out the tired old mix and replace it with some fresh potting mix or cut the roots back and place back in the same pot.
For these reasons, you want to size up just a few centimetres at a time. When you increase the pot size slowly and incrementally, this will encourage the plant to push out new roots and comfortably fill the pot. Once it has pushed down with it’s “feeler” roots and felt the bottom of the pot and then reached over and touched the sides, your plant will then begin to happily push out plant growth without expending all their energy growing roots to fill a too large pot.. It will fill out and plump up in rhythm with the root system.
When transplanting because a plant has outgrown its current pot, shift to a pot 5-10 centimetres larger in diameter. Select the larger size pot for plants that grow quickly. For slow growers, a pot that's 2.5 - 5 centimetres larger works well.
Visually, the container should be about half the height of your plant (or a third of the total height of the plant plus the container).
Using the Root Pouch Size guide you can determine the sizes of the pots in the range for your shrub or tree. If you are planning to incorporate a Waterpot Olla in the bag we would recommend either the Waterpot Bird Olla for it's long, slender length to fit comfortably in alongside your shrub or tree. If you have selected a wider pot, a Waterpot Small Round Olla would also be appropriate.
Please consider the overall width of the root ball of your new tree or shrub and the width of the Waterpot Olla in the bag.
You can easily fold down the edge of Root Pouch bags to form shorter bags. This is particularly useful when using them in pot-in-pots where a plant is potted into a bag and placed inside a decorative (and possibly drain-hole less) outer container. This makes grow bags so versatile and able to provide potting solutions for a number of scenarios! Try growing potatoes in the Root Pouch bags using the rolled bag method.