Before we start talking about how self watering planters are working you need to know some of the important terms used and basic information about planters. You can find this information here: Basic information about planters
How do self watering planters work?
A self watering planter holds a reservoir of water and when the soil dries out it draws up more water till it is satisfied. Overwatering is not a problem and the plants will always have moisture as long as the reservoir is filled with water. An additional advantage is that you can add fertilizer to the water itself. This will give food to the plants throughout the growing season and so improve the quality of plant growth.
A disadvantage of self watering planters is the effect of mosquitoes breeding in the water reservoir. To avoid this just add a couple of drops of oil to the water every time you refill the reservoir.
But there are a few things to consider and to watch for. The first thing you need to decide is if you want to water the plants form the top or from the bottom. If you don’t do that and you are watering from the top and you are using the watering reservoir at the bottom your plants will simply drown.
Watering from the top
If you prefer to water your plants form the top you can use it as a normal pot. The water will just drain out to the reservoir. The best thing you can do is to remove the water from the reservoir when you are watering from the top. The reason for that is that when there is still water in the reservoir and you keep watering from the top the soil stays permanently wet rather than having the time to dry out in between. As a result your plants will drown.
You can even remove the water reservoir when you are not using it. When you are watering your plants you can catch the overflow in a sink and when the planter stopped dripping you can place it on, for example, a saucer. But the next time you buy a planter don’t buy a self watering one, it will be cheaper to buy a normal planter instead of a self watering planter.
Watering from the bottom
When you want to water the plants from the bottom you need to use the self watering reservoir. Fill it with water and refill it when it gets empty. You will have to refill the water reservoir of your planter once or twice a week. The number of times you have to refill the water reservoir depends on the size of the planter and the type of plants you are using. The built-in water reservoir is designed to move the water upwards through the soil. When the soil is dry the moisture will continually move upwards, the advantage of such a system is that it always delivers enough water to the plants.
An important note is that if you decide to use the water reservoir you must never water from the top. It is also possible to snap of the bottom, the reason for that is that you can easily clean the reservoir and remove salts and algae.