Should You Water Potted Plants from the Top or Bottom? Here's What an Expert Says

Published on June 15, 2025

Plant people disagree on the best way to water their plants: Is it better to water houseplants and other potted plants from the top or the bottom? Should you pour water on the top of the soil and let it run down to the roots, or should you place the potted plant in a dish of water and let the water soak up through the soil to the roots?

Both ways of watering are valid, according to Campbell Vaughn, Agriculture and Natural Resources Agent for the University of Georgia. We asked him to explain the pros and cons of each watering technique so you can make the right choice for your plants.

Watering from the Top

This is the traditional way to water a houseplant or any other potted plant. You fill a watering can and pour out the water onto the soil surface. Top watering mimics rain soaking into the soil where roots can access it.

Pros

• It’s fast and simple. Top watering is quicker and easier than watering from the bottom of the plant.
• It’s good for plants with shallow roots. Certain plants like ferns and calathea get water much faster via top watering because most of their roots tend to be near the soil surface.
• It flushes excess salts. Top watering washes out the mineral salts from fertilizer that accumulate in a potted plant.
• It cleans dusty leaves. Many indoor plants benefit from top watering because it removes dust from leaves. Dust reflects or blocks sunlight, thus hindering a plant’s ability to photosynthesize, or make food for the plant. It also clogs the stomata, or tiny holes in the leaves, that allow a plant to absorb and release the gases it needs to breathe.

Cons

• Wet leaves encourage plant diseases. Wet foliage can increase fungal and bacterial diseases such as leaf spot or powdery mildew.
• Soil can get compacted. Repeated top watering causes potting soil to get compacted, making it difficult for excess water to drain from the pot and harder for roots to grow, spread, and take in oxygen and nutrients.
• Overwatering is more likely. It's tempting to pour too much water on top of your plants, which leads to problems like root rot and waterlogged soil. “You kill a lot more plants from overwatering than you do underwatering,” Vaughn says.
  
• Watering is uneven. It may be difficult to get the entire root ball watered from the top. Water may run down channels in the potting soil and miss some roots entirely.

Watering from the Bottom

Bottom-watering involves putting the potted plant into a tray or dish of water and letting the soil absorb moisture through the drainage holes in the pot.

Pros

• Watering is deep and even. The soaking method gets moisture to all the soil in the pot and distributes the water evenly.
• Leaves stay dry. No water touches the leaves with this method, which is good for plants prone to leaf spot, crown rot, or other fungal diseases.
• Overwatering is less likely. Because the plant absorbs the water, drowning the roots is less probable. It's important not to leave the potted plant in the water for too long, though, or you will overwater. “Take the plant out of the water tray when the top of the soil feels moist, or after a soaking time of 30 minutes to 1 hour,” Vaughn advises.
• Roots grow deeper. Roots will grow downward in the pot, towards that water source, leading to a stronger root system.
• It’s good for rootbound plants. Water tends to run off rootbound plants when they are top-watered. “Soaking is better for them,” Vaughn explains.

Cons

• Salt builds up. With no water flushing from top to bottom in the pot, mineral salts from fertilizer accumulate in the top layers of soil. “You should do a top watering every three to four months, even if you usually bottom water your plants,” Vaughn says. “Put the pot in a sink and run water over the soil, and let it all drain out. If those salts aren’t periodically flushed out, they can harm the plant.”
• It’s slow. It takes potted plants longer to absorb water from the bottom. “It may take up to a couple of hours for some plants to absorb adequate water from the bottom,” Vaughn says.
• It is not practical for large pots. A jumbo container with 16 gallons of soil is challenging to pick up and slip into a tray of water for bottom watering.

Which Watering Method Is Best?

There’s not a single best way to water all potted plants. Using a combination of top and bottom is likely your best bet, Vaughn says. No matter which technique you use, here are some best practices he recommends while watering container plants:

• Keep plants consistently moist. “Set up a watering routine for your plants and try to stick to it,” Vaughn says.
• Check soil moisture before watering. Even if you have a regular watering schedule, check the soil moisture by sticking your finger a few inches into the soil before you add more water (or use a moisture meter), Vaughn says. Water only when the top one to two inches feels dry.
• Make sure pots have good drainage. Always use pots with drainage holes.
• Don’t let plants sit in water indefinitely. If you are top watering, empty excess water from the saucer after about 30 minutes. “Otherwise, your roots will start building a film which is a rotting disease, a fungus, that coats the roots, and then the plant cannot absorb moisture at all,” Vaughn says.
• Know your plant’s water needs. Every plant species has specific water needs. Be sure you know yours. “Succulents need far less water than, say, a fern,” Vaughn says.