How does a watering globe work? The science explained

You've seen it in the shop, or maybe already ordered one: a frosted globe on a stick pushed into your flowerpot. But how does a watering globe actually work? And does it really work, or is it just a nice design object? Spoiler: it works — and the science behind it is surprisingly clever. It is in fact one of the most effective forms of automatic plant watering.

The physics behind the watering globe

A watering globe for plants works on the basis of two physical principles: capillary action and pressure difference. When you push the filled globe into dry soil, there is less water pressure outside the globe than inside. This pressure difference slowly pulls water outward. As soon as the soil is saturated, the flow stops automatically — until the soil is dry enough to absorb water again.

Step by step: the soil dries out causing the soil pressure to drop. The pressure difference between globe and soil pulls water through the narrow neck. Water slowly flows into the soil, directly to the roots. The soil is saturated and the flow stops automatically. The cycle repeats itself.

Why is this better than regular watering?

Roots get exactly the right amount — no overwatering, no drying out
Water reaches the roots directly, not the leaves or the surface
The water supply is continuous and even, without peaks and troughs
Less mould and root rot due to better plant watering

What determines the speed?

The drip speed is determined by three factors: the angle of the globe, the dryness of the soil, and the width of the neck. How this works exactly and how to adjust the flow for your plant, read in our blog about setting the flow of your watering globe.

Pro tip: always test 24 hours in advance. Push the globe into the soil a day before your holiday so you know the flow is right.

Does a watering globe work for all plants?

For most houseplants it works excellently as part of a plant watering system. Want to use it for outdoor plants or your vegetable garden too? For small or large plants you do need the right size. More info in our guide on the right watering globe size.