Self-Watering Planters
Self-Watering Device for Plants: The Main Types and How to Pick
The short answer
A self-watering device is any add-on or built-in system — a wick, a ceramic or plastic watering spike, a capillary mat, or a reservoir insert — that feeds water into soil gradually, so a plant can go longer between hands-on waterings.
Last updated September 2026
| Wick systems | A cord or strip of absorbent material carries water from a reservoir into the soil by capillary action |
|---|---|
| Watering spikes/globes | A bulb or spike inserted into the soil releases water slowly as the soil dries, refilled by hand or bottle |
| Capillary mats | An absorbent mat sits under multiple pots, wicking water up into each one from a shared water source |
| Reservoir inserts | A container-within-a-container design where a lower chamber holds water and feeds an upper soil chamber |
| Best for | Plants that want even, consistent moisture; not a fit for succulents or cacti that need to dry out between waterings |
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What's covered4
If you don't want to buy a whole new self-watering planter, a self-watering device does the same basic job as an add-on: it feeds water into soil gradually so the plant can go longer between hands-on waterings. There are four common types, and they're not interchangeable.
The four main types
Wick systems. A cord or strip of absorbent material (often nylon or cotton) runs from a water reservoir into the soil. Water climbs the wick by capillary action and spreads into the surrounding soil. This is the same principle used in many DIY and commercial self-watering planters.
Watering spikes and globes. A ceramic spike or a glass/plastic globe is filled with water and inserted into the soil. Water seeps out slowly through the porous material or a narrow neck as the soil dries. These are the most common retrofit option because they need no reservoir plumbing — you just refill the spike or globe itself.
Capillary mats. An absorbent mat sits under several pots at once, usually on a tray, wicking water up into each pot from one shared water source. This suits people managing a row of plants rather than one pot.
Reservoir inserts. Some devices are a container-within-a-container: a lower water chamber feeds an upper soil chamber through a wick or riser, similar in concept to a purpose-built self-watering planter but sold as a separate insert you place inside an existing pot.
Matching the device to the plant
The device only helps if it matches what the plant actually wants. Most common houseplants — pothos, peace lily, ferns, many tropicals — want soil that stays lightly, evenly moist, which is exactly what these devices are built to deliver.
Succulents and cacti are the exception. They want the soil to dry out fully between waterings, so a device that keeps soil constantly damp works against the plant's needs. If you like the convenience for a succulent anyway, let the device run dry for long stretches rather than keeping it topped up.
A ceramic watering spike or wick kit is usually the simplest way to try this out on a plant you already have, before committing to a full self-watering planter.
Sizing and refill rhythm
Bigger devices hold more water and need refilling less often, but there's no universal number — a small spike under a large, actively growing plant in bright light might empty in two or three days, while a bigger reservoir under a slow-growing plant in low light could last a few weeks. Check the device by sight for the first couple of weeks to learn its actual rhythm for your specific plant and light conditions, rather than guessing from a generic schedule.
When to skip a device and just repot into a self-watering planter instead
If you're setting up several plants that all want even moisture, or you're already planning to repot, a dedicated self-watering planter with a built-in reservoir is usually less fiddly long-term than retrofitting a device into a pot that wasn't designed for one. Devices are best for a single plant in a pot you don't want to replace, or for testing whether self-watering suits your routine before you commit to new pots.
FAQ
Do self-watering devices work for all plants?
No. They suit plants that want consistent, even moisture, which covers most common houseplants. Succulents and cacti want the soil to dry out between waterings, so a device that keeps soil constantly moist works against them unless you deliberately let it run dry for long stretches.
How often do I need to refill a self-watering device?
It depends on the device's water capacity, the plant's size, and light and temperature conditions. Small spikes or globes might need refilling every few days; larger reservoir systems can go a few weeks. Check by sight or by lifting the pot until you learn your specific setup's rhythm.
Can I add a self-watering device to a pot I already have?
Yes — wick systems, watering spikes and globes are all designed to retrofit into an existing pot, unlike a built-in reservoir planter, which requires the pot itself to have the reservoir chamber.
Are ceramic watering spikes better than plastic ones?
Both work the same way: porous material lets water seep out slowly into the soil. Ceramic spikes are typically more breakable but don't degrade from UV or water exposure the way some plastics can over years of use. Either works for the same basic job.