Wondering how to bottom water plants? Watering is a critical part of plant care, and bottom watering can help prevent yucky things like fungus gnats. Learn everything you need to know about this easy strategy, including how long to bottom water plants!
How to bottom water plants
Watering is the number one killer of houseplants. I have nothing to back this up other than a strong suspicion and personal experience 🙂 But I swear it’s true. People think plants need sooo much more water than they actually do.
Giving your plant too much water can lead to soggy soil and root rot. And overwatering can also lead to problems with pests (see my post about what causes fungus gnats and how to get rid of them). Fungus gnats are one of the most annoying parts of owning houseplants.
Today we’re going to chat about one of the easiest ways to avoid fungus gnats and moderate your watering routine: bottom watering! What’s bottom watering, though? Well, it’s exactly what it sounds like. Watering from the bottom of the plant. Sorry to say we won’t need our cute watering cans for this one.
How to water houseplants
I think the easiest way to water plants is to set them all in the shower and water in bulk used the shower head. This has the benefit of cleaning dust off of the leaves and most closely mimics the type of watering they would get in nature. Also it’s just kind of relaxing.
But lugging all of your plants to the shower isn’t always practical. So the second best option is to water them thoroughly in a sink or over a drainage saucer until the water flows out of the pot’s drainage hole. This ensures the soil can be thoroughly soaked and the excess water exits the pot, helping to prevent soggy soil and root rot.
(Note: I do have a post about how to plant in pots without drainage, but I would only use that lazy method for super low maintenance plants and it is not the preferred option. Also, you’re going to get shit from every houseplant person ever for doing it, so be warned!)
Why bottom water plants?
But…yes, another but! But watering from the top isn’t always the best option for three reasons.
First, plants with delicate foliage can throw a fit if the top layer of their soil stays too wet. An example of this is the string of hearts plant (see my string of hearts plant care guide for more) and the hoya rope plant (see the hoya rope plant care guide as well).
When I water my string of hearts from the top, I’d say 75% of the time one of the leaves near the top yellows and dies off. So frustrating. The leaves just don’t like being wet.
Second, fungus gnats (those annoying tiny bugs that fly into your face in your house) lay their eggs in the top layer of a potted plant’s soil. And they really really need moist soil to flourish. Therefore, watering from the top gives them that cozy wet environment they need to raise their annoying little families.
And they reproduce like crazy, so removing their preferred habitat means they won’t lay eggs in your plants. Bottom watering typically does not get the top few inches of your plant’s soil wet. It might get damp, but not wet. And it will dry quickly.
Third, I think that bottom watering just helps you avoid overwatering your plants. The plant generally takes in the amount of water it needs naturally. You just need to make sure you aren’t bottom watering too much.
It also gets the water directly to the roots that really need it on the bottom of the pot. When you water from the top, you’re watering a lot of soil.
What do I need to bottom water plants?
So how does bottom watering look logistically? Well, I have seen people do it a zillion different ways. You basically just need a container with water and a pot with drainage holes. The container can be as large as a tub and as small as a drainage saucer or bowl.
As far as drainage holes go, I like to use plastic nursery pots for bottom watering. That’s because they typically have more holes, including holes around the edges of the pot’s bottom. This allows them to soak it all in.
However, I have plants in non-nursery pots that I occasionally bottom water—like my string of hearts. It’s in a cheap ceramic planter I got from the Target Bullseye’s Playground second. Before planting in it, I just drilled some holes in the bottom of the pot.
How long to bottom water plants
Once you have your container with water and your plant, it’s time to bottom water! I am using my sink for this example. It’s convenient for me. I just fill it up with a few inches of tepid water.
Then I set my plants in for about 10 minutes. You will likely even notice the water level going down if you have enough plants in there! Especially if you’re bottom watering from a drainage saucer or something.
Your plant will soak up the water. Think of it like this: imagine you were wearing a giant fluffy skirt and you sat in a puddle of water. Your skirt would soak up all of the water, but your shirt might stay dry. Think of it like that. It’s not magic 🙂
After about 10–15 minutes, stick your finger into the top inch or so of the soil. If it is damp, you’re good to go. It shouldn’t be wet—just damp. Remove the plant and monitor over the next week or so as you establish a bottom watering schedule.
Disadvantages of bottom watering
Despite the benefits of bottom watering, I don’t exclusively bottom water even my pickiest plants. That’s because I find it’s often easier to clean their foliage by gently spraying water from the top like rain. (I also have a post on how to clean houseplant leaves.)
Watering traditionally also helps to ensure you flush your soil. Flushing your soil is essentially just watering a plant thoroughly until water flows out of the drainage hole. This helps get rid of excess salt buildup in your soil.
Therefore, you should shoot to water traditionally from the top every so often to keep your plant happy and healthy.