Watering plants and good water drainage

One of the most common questions new plant owners have regarding houseplants is how much and how often a plant should be watered. Although each plant variety has its own needs, for most, it all comes to water drainage.

Watering is intrinsically related to drainage. When gardeners talk about drainage, they refer to the capacity of the soil or the pot to let excess water drain out after watering a plant. Once the soil gets saturated with water, any excess needs to drain out of the pot and soil for a plant to stay healthy. When there is excess moisture in the soil or pot, the roots suffocate and eventually rot. Therefore, the plant’s health starts declining and eventually dies. 

Watering plants in pots with water drainage

The best way to water plants in pots with drainage holes, is to water the soil thoroughly, always making sure that the excess drains out through these drainage holes. Once the soil is completely moist, you don't need to water it again until the soil feels dry to the touch. The soil should dry at least two or three inches deep. If the pot comes with a drip tray below, discard the water that falls in the tray to avoid root rot.

Watering plants in pots without drainage

So, what happens if a pot does not have drainage holes? Well, it may sound contradictory, but drainage isn’t always necessary, although it makes caring for our plants easier. 

Drainage holes allow excess water to escape. If you add too much water at one time, it seeps out the drainage holes, and you can empty the drip tray, so the plant doesn't drown. But if you're careful and don't get into a situation where you're not adding too much water at any one time, then the holes aren't necessary. 

The best way to water a plant in a pot without drainage is to water it just enough to keep the soil moist. The amount of water poured into the soil can’t be excessive. The right amount will depend on the size of the pot and the type of plant. For example, some succulents and cactus plants have a very shallow root system, so they drink water from the first layers of the soil. That means that there is no need to water the soil too deep. 

Adding pebbles below the soil for drainage 

Adding pebbles inside a pot is an urban myth. It sounds logical that pebbles should help excess water to drain down the soil. But combining rocks and soil can get the soil compacted and trap water in small pockets. These pockets of water will eventually cause problems. Also, the pebbles can end up clogging the drainage holes or create air pockets that can provide a perfect habitat for fungus and bacteria.