SUStee plant-watering checker refills, set of 4

How to use it

The colour-changing core gives you a visual cue about moisture in a pot: it turns blue when there is enough water, then white when water runs out. That makes this set of small SUStee refills useful for checking a plant at a glance instead of relying only on the surface of the potting mix.

Place the checker in a pot and read the indicator, the set is described as refills, so don’t assume it includes a complete watering checker. The instructions also say to use the straw as it comes out of the package, but offer little detail beyond that.

What’s more useful in practice: a quick colour cue, or a more hands-on check of the soil? This suits the first approach, though it won’t tell you how much water to add or replace checking the plant itself.

Pros

The main advantage is simplicity. A blue indicator means there is enough water, while white signals that it has run out. For someone looking after several pots, that change can make it easier to spot which one needs attention while watering, rather than treating every plant the same.

The core is made from 100% natural fibre and is biodegradable by bacteria in the soil. Its estimated lifespan varies with the growing medium: according to the manufacturer, it is about 6–9 months in organic soil, 9–12 months in inorganic soil, and 1–2 years in hydroculture, water moss and bark. That variation matters when deciding how often you may need replacement cores, the longest estimate applies to particular growing setups, not every pot.

It makes sense if you want a straightforward visual indicator and already have the checker the refills are intended for. A simple finger check or a basic watering routine may suit you better if you prefer not to keep track of a separate indicator.

Spec sheet

• Product: Small SUStee refills, set of 4
• Indicator: Blue when water is enough, white when water runs out
• Core: 100% natural fibre, biodegradable by bacteria in soil
• Shell: Polycarbonate around the discolouration part
• Estimated core life: 6–9 months in organic soil, 9–12 months in inorganic soil, 1–2 years in hydroculture, water moss and bark

The lifespan figures are estimates, and the supplied information doesn’t explain how to tell when a core itself needs replacing beyond its stated service life. The shell is polycarbonate, so the biodegradability claim applies to the natural-fibre core, not necessarily the whole refill.

My take

This is a practical consumable for someone who already uses the SUStee watering checker and wants a colour-based reminder for potted plants. It favours quick visual checks over a more basic routine of feeling the soil, but it is not a substitute for judging each plant’s needs. Different growing media also mean the core’s useful life can vary considerably.

Best avoided if you need a complete watering checker, since the product is presented as a set of refills and the listing does not confirm that a full unit is included. It is also a less suitable fit if you want a precise moisture reading or specific watering instructions: the information here only describes the blue-to-white indicator. Choose it for the simple cue, and make sure replacement cores are what you actually need.