A self-watering planter is a pot with its own water tank. You fill the tank every week or so, and the soil draws water up from it as the plants use it. No pump, no timer and no electricity: the whole thing runs on capillary action, the same effect that pulls water up a paper towel dipped in a glass.
The four parts
- The reservoir: a sealed space in the base that holds water.
- The growing bed: the upper part that holds the potting mix and the plants, sitting above the water.
- The wick: the connection between the two. It can be a cord of cotton or nylon, a column of potting mix that reaches down into the water, or a perforated cup packed with mix.
- The overflow and fill tube: a hole at the top of the reservoir so it can never overfill and drown the roots, and a tube to top it up from above.
Why the water goes up
Water molecules stick to the fibres of a wick or to particles of potting mix (adhesion) and to each other (cohesion). Together those pull water up through narrow spaces against gravity. As roots take water from the mix around them, that mix gets drier, and the wick draws more up to replace it. The plant sets the pace: it drinks what it needs, and the soil stays moist without sitting wet.
Why they suit balconies and busy people
Pots in small spaces dry out fast, especially on a windy balcony on a hot day while you are out. A reservoir buys you days rather than hours. It also waters from the bottom, so roots grow down toward the water, and less water is lost to evaporation off the surface or run-off out of the drainage holes.
The same principle, scaled up, is a wicking bed: a raised garden bed with a water reservoir under the soil.
How to use one properly
- Water from the top at first. New seedlings have not grown roots down to the moist zone yet, so water them from above for the first couple of weeks.
- Then fill the reservoir. Top it up through the fill tube until water runs from the overflow, and check it weekly, more often in a hot spell.
- Flush now and then. Fertiliser salts can build up in the mix. Every month or two, water heavily from the top and let it drain through the overflow.
- Use potting mix, not garden soil. Heavy soil wicks poorly and stays soggy.
- Keep the reservoir covered. Open standing water breeds mosquitoes, so make sure the fill tube has a cap or the gap is screened.
Why ours were built from reclaimed materials
Feedback Organic has designed and built its own planters, which we call FO Originals: the Selfie herb box, the CornerStore, the High Rise and others. Every one is self-watering, with a reservoir in the base, and every one was made from 100% waste-reclaimed materials. A planter that holds its own water suits anywhere nobody has time to water every day.
We are not making them right now. If you would like one, you can tell us which in the Loop Shop, and if enough people ask, we will look at building another run. The shop also has self-watering pots and wicking beds from Australian shops.
And if you run a kitchen, the leftovers can be part of the same loop: our weekly food waste collection takes them so they can grow food again.
Sources, checked 17 October 2026: Gardening Chores, Self watering planters: how they work; Easyplant, How do self watering pots work; Deep Green Permaculture, Self-watering tray.