As the name suggests, self-watering pots are self-irrigation containers that provide continuous water streams into the soil. The pot consists of four essential elements: a growing bed, potting soil, water reservoir, and a wicking system. The pot uses a ‘capillary action’ system where water is drawn from the reservoir to the soil via a wick.
These pots have gained popularity in recent times due to the busy lifestyle of modern life. Simply fill the reservoir with water and the self-watering system keeps the soil moist for days. However, before you invest in a self-watering pot, you need to consider a few issues before deciding that it’s the right pot for your needs.
The most common problems associated with self-watering pots are:
- Breeding grounds for mosquitoes
- Not suitable for all plants
- Algae and fungus gnats
- Not ideal for large plants
- Not ideal for outdoors
- More expensive than regular pots
- Not a set-and-forget system
Breeding ground for mosquitoes
The most common problem with self-watering pots is the water held by the reservoir. It’s the perfect hotbed for mosquitoes to lay their eggs because it’s still water. Most eggs hatch within 28 hours, and mosquitoes will multiply because of soggy conditions. This problem is more severe if you live in a country that is humid and warm.
To prevent the self-watering pot from being a mozzie breeding nest, you’d need to flush the water out every few days. Once you fill the reservoir with water, you can cover any access holes with a small square of fly screen mesh.
Alternatively, you could find a pot design where the water access is sealed off, such as this one I found on miei.com.au:
Not suitable for all plants
Self-watering pots are unsuitable for plants that prefer dry or well-drained soil, such as cacti and succulents. The continuous moisture that is being fed into the soil puts succulents at risk of dying from over-watering. Succulents are accustomed to the desert environment and so need to dry out between watering sessions. Self-watering pots do the complete opposite.
Algae and fungus gnats
The continuous soil moisture that self-watering pots provide means that the soil is prone to algae and fungus gnats.
The growth of algae is caused by excess moisture in the soil. Algae is a problem because it significantly harms the growth of plants by competing for nutrients and water. Algae also release spores that are harmful to infants, so if you have an infant, you’ll need to carefully monitor the pot – which is ironic to have a self-watering pot in the first place.
Fungus gnats are fruit fly-sized insects that look like mosquitoes that affect mostly indoor houseplants. These pests are attracted to soil moisture as they lay eggs on organic matter on the soil’s surface. In less than a week, the eggs hatch into larvae, which burrow into the soil to feed on fungi and decaying plant material.
Not for large plants
Self-watering pots are not suitable for large plants that have long and sophisticated root systems. The same goes for standard pots, but the problem is more severe in self-watering pots because the roots reach the pure water of the reservoir.
Take, for example, this pot on Amazon:
With roots sitting in water, the plant may die from over-watering.
Not ideal for outdoors
Some self-watering pots don’t have an overflow opening, such as this one:
Without a free-flowing drainage hole or an overflow hole, these self-watering pots are prone to waterlogging and, thus, potential root rot. And so, by leaving these pots outdoors, it’s exposed to receiving excess water from the rain.
Horticulturalist Kim Carlisle, shared on Quora.com about her experience working at a garden center with self-watering planters. She placed a few large self-watering pots for display, and during long periods of rainy weather, the young plants would have rotted if she didn’t tilt the pots to drain the reservoirs. Root rotting was less of a problem with mature plants with a branchier root system because water is used faster.
To counter this problem, she drilled holes about an inch from the bottom of the pot so that only half of the reservoir can be filled. However, this allowed mosquitoes to enter the reservoir to start their breeding cycle.
More expensive than regular pots
Self-watering pots are typically more expensive than the standard pots due to their construction and the extra parts. Prices will depend on the size and style you choose. Buying self-watering pots can impact your budget, especially if you’re planning to change all your current pots to self-watering ones. If your plants tend to die from underwatering, perhaps self-watering pots are a worthwhile investment.
Not a set and forget system
A common misconception among new plant parents is that you can fill the reservoir with water and leave it. This is not true. You still need to understand the plant’s needs and monitor, assess and provide appropriate soil. Self-waterers don’t mean you fill the reservoir and then walk away.
Self-watering pots offer excellent benefits and convenience for busy individuals. However, before heading to the nursery, you need to research the plant that the pot is for. If the plant doesn’t mind the constant damp soil and does not grow extensive roots, then you’re good to go. Also, look around for a pot that preferably has the water access sealed to prevent mosquitoes from breeding inside. Good luck!