Are drainage holes necessary?
There are a lot of planter options out there, as well as many opinions in the drainage holes/no drainage holes/rocks at the bottom of planters/cachepots "debate." Here are what we have found works for us at Perrico Plant Co.
With drainage holes:
We use a lot of terra cotta pots in our personal collection. Terra cotta is a porous material that allows water to seep through the edges of the planter causing the planter will feed damp for a day or so if you've watered a lot. Terra cotta is a great option for plants that use well-draining soil and require minimal watering, such as succulents, cacti, snake plants, and ZZ, because it allows as much water as possible to escape - both through the planter itself and through the drainage hole.
Remember to find a saucer for any planters with drainage holes that do not come with a saucer already. Most garden centers will have clear plastic saucers that will blend in with your decor. If saucers aren't your thing, a lot of house plant owners will move their plants to the bathtub/shower for the day, water them well, and allow any water to drain out before placing them back in the house.
As a general rule of thumb: if enough water comes out of the planter to sit in the saucer, pour that standing water out after a few minutes so the plant doesn't absorb too much water.
If you are going to move your plants outside at any point in the year, we recommend only using planters with drainage holes to ensure any rain water will be able to properly drain from the plant.
If you're a true beginner to caring for house plants, we recommend you stick with planters that have drainage holes with saucers. You're still figuring out how much to water and when, so it's best not to risk overwatering and killing your new plant family member.
Without drainage holes:
The key to planters without drainage holes is: do not overwater.
We have a few ceramic planters that do not have drainage holes and we do not put rocks at the bottom of those containers. They are filled only with soil and plants. Rocks at the bottom create a place for standing water that may never get absorbed into the soil or roots of the plant and there is no other way for the water to escape from the planter.
We have plants with a variety of needs in these planters without drainage holes - specifically, a prayer plant that requires watering a bit more often than most of our other plants and schefflera & ficus that can be watered weekly with no additional needs. The main thing to keep in mind for these plants is that we make sure not to over water. For reference, in our home these plants are in 6" ceramic planters and receive only 1/4 to 1/3 cup of water every 7-10 days. The prayer plant gets that same amount of water at least every 7 days (or whenever the leaves get a bit droopy).
Cachepots:
Cachepots are when you put a plant with drainage holes (usually a plant still in its plastic nursery planter) into a planter without drainage. This can be a great trick and allow you to get the best of both worlds if you remember to do two things:
- Pour out any water that remains at the bottom of the larger pot after watering after a few minutes
- Don't keep your plant in it's nursery pot for too long. We have some repotting tips, including how to tell when a plant needs to be repotted, in a video we made here.