Avid gardeners know that a misstep in the watering routine can significantly impact a plant, sometimes leading to plant death. That’s why bottom watering has become a common practice, but many gardeners still wonder if it’s okay to do so with plants in terracotta pots.
You can bottom water plants in terracotta pots just like you would bottom water plants in any other type of pot, as long as the pot has drainage holes. Unglazed terracotta pots are porous, so plants in such pots will need more water as the terracotta will absorb a lot of water.
In this article, I will further explore how you can bottom water plants in terracotta pots. I’ll also explain how to do it properly to maximize the benefits. Read on!
Can Terracota Pots Be Submerged in Water?
Terracotta pots can be submerged in water instead of simply being placed in a tray or sink full of water. The clay’s porosity allows it to absorb moisture and also facilitates faster drying when taken out of the water.
If the air temperatures are not freezing, submerging your terracotta pots in the water should be safe. Otherwise, the water within the clay will freeze and expand, causing cracks in the material. In the worst case, your pot may even break.
In gardening, you can find various terracotta pots designed for different purposes, so you’ll approach bottom watering differently with each type.
Fully Glazed Terracotta Pots
This pot has a smooth finish on both the inside and outside faces. Since clay pots tend to absorb moisture from the soil, glazing the pot prevents this moisture absorption. It’s ideal for plants that need adequate moisture retention.
Fully glazed terracotta pots work the same way as plastic or other waterproof plant containers. So if you want to bottom-water your plants in fully glazed terracotta pots, you must choose containers with drainage holes for the water to come through into the pot.
Partially Glazed Terracotta Pots
Some pots are glazed only on one side: inside or outside. And depending on which side the glaze is on, you’ll find different functions.
- Glazed inside: This pot helps prevent moisture loss from the soil, making it suitable for plants that prefer to stay in constantly moist soil.
- Glazed outside: Although this pot is often used for aesthetic purposes, the unglazed inner layer presents an added benefit. It stores excess water, so when the soil dries up, a small amount of moisture in the pot can move toward the soil through a suction force from the roots. The moisture in the unglazed surface also helps keep the soil warm.
You can submerge these pots in water if you need to bottom water your plants, but they won’t absorb water from the sides similarly.
Remember that the glaze prevents water from moving between the terracotta and the soil, so there should be adequately sized drainage holes to ensure the water can enter.
Fully Unglazed Terracotta Pots
This terracotta pot doesn’t have a glossy finish on either side, enabling the clay to absorb and wick away moisture efficiently. However, you must soak the pot longer to saturate the soil enough because the terracotta absorbs much of the water.
This moisture on the pot’s walls will quickly dry once you take it out of the water, so it won’t be sufficient to water your plants after you’ve taken them out of the watering station.
Pros and Cons of Bottom Watering Plants in Terracotta Pots
Bottom watering is often recommended to rehydrate dry soil thoroughly. It’s also an efficient watering method for plants that don’t like to get their leaves wet. However, the type of container your plants grow in can also contribute to the effectiveness or failure of the process.
- There are various types of terracotta pots to choose from. As discussed above, you can choose a terracotta pot depending on the kind of plant you plant to bottom water. A good rule of thumb is to use unglazed pots for plants that prefer dry soil between waterings. Conversely, you can use partially or fully glazed ones for those that like to sit in constantly moist soil.
- Terracotta pots are sturdy enough to withstand submersion in water. Making terracotta pots involves baking clay at high temperatures until the material becomes tougher.
- Unglazed terracotta pots can wick away excess moisture to prevent soggy soil. Since there’s no hard and fast rule regarding how long you should soak the pot, your soil can come out too wet. The breathable nature of terracotta pots can help dry out the soil and make it safe for your plant’s roots.
- Mold can grow on terracotta pots. If the outer layer of the pot is glazed, the inner layer can stay moist for longer. Even unglazed pots can promote mold growth if the room has high humidity. Mold and other fungi can thrive in the soil long enough to damage the pot’s appearance and your plant’s health.
- Terracotta pots can get heavier when soaked. Terracotta pots are already heavier than pots made from other materials, and soaking them in water will double their weight. However, fully glazed terracotta pots don’t absorb water, so weight isn’t an issue.
- Terracotta pots are sensitive to freezing temperatures. The freezing and thawing of moisture in the clay in winter can break outdoor terracotta pots. Therefore, it’s best to avoid bottom-watering outdoor plants in terracotta pots as early as fall, before the first frost.
- Salts and minerals can accumulate in the soil over time. This accumulation is true about bottom watering regardless of the pot’s material because there’s no way to flush the excess salts out of the soil. That’s why occasional top watering is recommended.
- ‘Patina’ (white mineral deposit patches) can form on the pot. Bottom watering terracotta pots may cause white mineral deposit patches to form on the pot, especially when using tap water rich in minerals
How To Bottom Water Plants in Terracotta Pots
Done right, bottom watering plants in terracotta plants is a useful gardening technique. Here are some steps to ensure you’re maximizing the benefits of bottom watering for your plant and making the process convenient.
1. Choose Small or Medium Terracotta Pots
Unglazed or partially glazed pots will get heavier after soaking in enough moisture. Add this to the water absorbed by your potting mix, and you risk pulling a muscle when getting the pot out of the tub.
It’s best to bottom water only those plants grown in small or medium-sized terracotta pots to make moving them in and out of water tubs easier. In addition, small plants with lush foliage can benefit from bottom watering.
The benefits to plants with thick foliage are doubled if you have fussy plants with low-lying leaves almost touching the soil. For instance, African violets dislike getting their foliage wet. They will develop leaf spots when cool water droplets sit on the surface of the leaves.
2. Place a Mesh or Coffee Filter at the Bottom of the Pot
Bottom watering sends water from the tub to the soil in the pot through drainage holes. However, depending on the drainage holes’ size and the soaking duration, your potting mix might flow through the drainage holes.
To prevent this from happening, you can place a coffee filter at the bottom of the pot before pouring the potting mix in. The water can seep through the coffee filter, but the soil won’t be able to pass through the filter. However, coffee filters might slow down the process of saturating the soil.
Alternatively, you can use a mesh pad. I recommend the Grandisk Flower Pot Hole Mesh Pad (available on Amazon.com). The product is made from plastic and doesn’t slow down the soaking of the soil. It also effectively prevents the soil from leaking out of the pot.
3. Soak the Pot in Tepid Water
When watering plants, you should always use tepid water with temperatures between 68 and 77 °F (20 and 25 °C). Cold water can cause cold shock on the roots, while hot water can scald them.
In addition, cold water can damage your terracotta pot, especially when you place it under direct sunlight after soaking. The drastic temperature change can compromise your pot’s lifespan and negatively affect your plant.
It’s also best to use distilled water instead of tap water. Remember that there’s no way to leach excess salt from the soil when bottom watering. Using distilled water can eliminate this problem and dilute the salt or acid concentration in the soil after applying fertilizers. Moreover, distilled or filtered water will be less likely to leave a ‘patina’ (white mineral deposit patches) to form on the pot.
4. Soak the Pot Long Enough To Saturate the Soil
If it’s your first time to bottom water your plant in a terracotta pot, set a timer and check your potting soil regularly to see how much time it takes for the top layer to feel moist. Stop the timer and record the time.
After doing this for some time, you’ll get the proper duration for soaking the pot and avoid overwatering or underwatering your plant.
5. Allow the Pot To Stand With the Drainage Holes Exposed
After taking the terracotta pot out of the water, place it on a plant saucer or tray with protrusions to elevate the pot. Doing so will allow the excess water to drain out of the drainage holes at the bottom of the pot, and you won’t have to worry about overwatering your plants. If your pots are completely unglazed, the terracotta itself will help wick away excess moisture from the soil.
You can learn about how bottom watering can lead to overwatered plants in my post, Can You Overwater Your Plants by Bottom Watering?
Unglazed and partially glazed terracotta pots are excellent plant containers because they provide a breathable surface to suck excess moisture out of the soil and protect the plant from soggy conditions. At the same time, they can deliver the water stored in the clay material back to the soil when needed.
However, be careful not to bottom water outdoor plants in terracotta pots during freezing temperatures to prevent plant and pot damage.