I can hear you from here:
“All this information is well and good, but, like, HOW do you water plants? Is it a sprinkle a day? Submerging them in water weekly?”
You may have heard the terms top watering vs bottom watering being thrown around, and why you should do one over the other. I do both, as they each have their benefits.
Top watering- I do this one regularly, as it is easy to go around with a watering can, watering the top of the soil. I usually give my plants a good water by watering the soil a bit at a time, until water drips out of the drainage holes at the bottom of the pot. This indicates that the soil has absorbed enough water. Note: If you dump a bunch of water at a time, water will start coming out of the drainage holes before the soil has enough time to hold the water, so slowly watering works best.
For plants that like consistently moist soil, I tend to water a lesser amount, more frequently. I.e. when the top 1-2" of soil is dry, I give them enough water to moisten the top couple inches of the soil, but not enough for water to run through the bottom.
Try to water the soil only, avoiding the leaves as much as possible. Constantly wetting the leaves of indoor plants can encourage rotting, leaf discolouration and other leaf issues. For leafy plants with dense foliage, getting a watering can with a narrow spout can help reach the roots easily, without wetting the leaves. Leave the classic watering cans with the multiple holes for the outdoor garden, as your outdoor plants receive tons of sunlight to dry their leaves off well throughout the day.
Top watering of a Pilea glauca plant, using a watering can with a narrow spout.
Bottom watering-Some plants do better with bottom watering i.e. placing the plant pot with drainage holes within a container of approximately 1 inch of water, so that the water is soaked up from the bottom. One example of such a plant is the African Violet. I mostly water my African Violet from the bottom, so that it can soak up the water it needs. I have found that when I get lazy and water from the top, its leaves get mushy and discoloured. These leaves do not like to get wet.
In general, bottom watering is known to encourage stronger roots, and to enable the plant to take up just enough water for its needs. Ensure that after bottom watering, you remove any water that has not been absorbed after 20-30 minutes. Despite the benefits of bottom watering, every once in a while, it is good to give your soil a good top-down rinse to prevent the buildup of minerals at the top of the soil.
Aglaonema Siam Aurora being bottom-watered
After 30 minutes of bottom-watering. This plant was not underwatered, hence not much water being taken up.
Saving an underwatered plant
The goal of saving an underwatered plant is to rehydrate it. The best way to do so is by placing the plant pot with its drainage holes in a container of water to allow the plant to soak up as much water as it needs. Keep an eye on the container. If the water is quickly soaked up within a few minutes, add more water. You want to keep this plant in water for about 20-30 minutes. After, check the soil with your fingers or a moisture meter to ensure that the soil is evenly rehydrated.
Watering an underwatered plant from the top can work, if you do so slowly. The soil of an underwatered plant is so dry, that water easily runs right through, without the plant actually getting watered. Watering from the bottom give the soil time to absorb the water, and gives the plant time to take that water in.
If the leaves were wilted, look out for a recovery of the leaves once you have given it a good drink of water from the bottom.
Wilted leaves on Zebra plant due to lack of water (in this picture, the plant is not severely underwatered. These plants react visibly when in need of water)
You may need to prune off any dry, crispy leaves. These leaves are no longer useful for the plant, and can therefore be removed. If there are no green leaves left, prune off all the dead leaves and leave the stem if it is still green. This plant would need much more time to readjust and create new leaves. Keep in mind that you may have to modify your future watering of this plant, as it no longer has leaves to transpire and will need less water than usual.
Saving an overwatered plant
This depends on the severity of the issue. A plant with a few yellowing leaves or brown tips from overwatering, can be saved by just removing the yellowed leaves or snipping the brown tips, allowing the soil to dry out, and reducing the amount of water it gets. However, plants with more global issues such as mushy stems and roots need additional care.
If you notice that your plant has mushy stems, cut that part of the stem away, even if it means cutting some of the leaves off with it. If the stem is mostly mushy, you may need to cut the plant down to a stub. Leave as much of the stem as you can.
For mushy roots, take a pair of clean shears and snip the mushy roots off ABOVE the rotted area. You may also need to repot your plant in drier soil. This is sort of like a reset button.
Roots (and tubers) of a ZZ plant. Cut the mushy root at the red line.
Place an overwatered plant that can tolerate brighter light, in a brighter spot with additional circulation (such as a fan) to allow for more moisture evaporation.
What if my plant is too far gone?
There is a possibility that the plant is too overwatered or underwatered. If the roots and stem of the plant are dry beyond repair with no green stem, or if a plant’s roots and stem are mushy beyond repair, you may need to get rid of it as it is past saving. If possible, look for a piece of the plant that can be propagated before getting rid of it (again, that piece needs to be healthy, not dry and brittle, or mushy).
I really do hope that this 3-part guide helped you be more comfortable and confident in watering your houseplants. As I mentioned earlier, nobody is perfect, and it is inevitable that we may let something slip, but with this guide, you should now be able to catch any errors earlier rather than later, or be able to rehab your plant back to health. I will leave you with these final tips to keep in mind:
- The type of soil your plant lives in can affect the frequency with which you need to water your plant. This is a whole other factor that is closely related to watering, but needs its own blog post. Perhaps an in-depth blog on soil types is needed? Let me know if that would help.
- Some plants like Calatheas can be sensitive to tap water. Try using rainwater if possible or allow your tap water to stand for a day before watering these plants.
- In general, using room temperature water for your plants is best. Allowing water to stand will ensure that the water you use is the right temperature.
- The type of pot your plant is in can also affect how often you need to water. Terracotta pots absorb moisture, which can result in soil drying out quicker. The plastic nursery pots retain more water.
- Ensure that your plant pots have drainage holes. This will allow for excess water to drain out of the bottom, which you can then dump out of the saucer below, to prevent your plants from sitting in pools of water for an extended period of time.
- If you are not sure whether your plant needs water, wait another day or 2 and re-assess. As mentioned earlier, overwatered plants are more common, and can be more difficult to rehabilitate than underwatered plants.
Let us know whether you have been able to save a plant from being over-watered or under-watered. Let's hear your success stories.
You’ve got this!