The subject of overwatering houseplants is a bit of a bug bear for me. Can you overwater plants?
In short, yes you can. But there is much more to it than that.
Oversimplifying Overwatering
The statement that ‘overwatering is the number one killer of plants’ gets thrown around A LOT. I think it caught on so quickly because it offers an easy solution for beginner indoor gardeners.
Have you also heard these:
‘If your plant’s leaves are turning yellow, you’re overwatering.’
‘It is much better to under-water than over-water.’
It makes you feel better that there is something so simple you can do to make your plants grow better.
But it is ignoring a lot of other factors. Watering properly is not the only thing that will stop your leaves turning yellow.
The main problem that leads to things like yellowing leaves and, subsequently, the overwatering warnings is root rot.
How Do You Solve Root Rot?
Root rot is caused by a fungus. This fungus thrives when a number of circumstances come together:
- Excess moisture in the soil around the roots.
- Low oxygen levels around the roots.
- The roots of the plant are weak.
Too much water will provide the excess moisture, but that water would need to be sitting in the soil permanently for that to be a problem.
This can be partly solved by making sure the soil your plant sits in is draining to the right levels for your plant. This means that excess water passes through the soil after the soil has taken up all the water your plant needs.
A soil that drains the right amount for a particular plant will also help with the problem of low oxygen levels around the roots because a well-drained soil will aerate more easily.
So, we have one major solution to root rot: a soil mix that is suited to the plant so that it drains well. Next, we need to address one more major solution that will complete the picture.
A plant will draw up water to help it photosynthesise. This is when a plant turns sunlight and water into energy. This is when it feeds itself.
If a plant is not getting enough light to photosynthesise as much as it needs to then it will not draw up as much water and the water will stay in the soil longer. In addition, the roots will become weak because the plant is not getting enough energy from photosynthesis.
Can you see where this is going?
The next major solution to root rot is making sure that the plant is getting the right amount of light.
If it can photosynthesise properly then it will use more water and the roots will get stronger.
We’ve ticked all the boxes for overcoming root rot I think:
- Excess moisture – Correct levels of light mean more photosynthesis and more water used. Properly-drained soil means less water held in the soil.
- Low oxygen – Properly-drained soil means more aeration around the roots.
- Weak roots – Correct levels of light mean more photosynthesis, more energy and stronger roots.
The combination of the right soil mix and the right amount of light will make your plant feel much better.
In fact, these are the fundamentals of houseplant care. If you can get these right from the start then you will have a great chance of keeping your plants healthy.
But What About Watering?
With these fundamentals covered, overwatering becomes less of a problem, but will still be something to be wary of.
Watering is not something that you do on a regular schedule. It will depend on the temperature of the room, light levels on any given day, the time of the year.
Checking the moisture level of the soil is the best way to decide when you need to water your plant.
If your soil mix is correct and the light conditions are correct, then your plant will use as much water as it needs and the moisture level of the soil will tell you when to water.
This is where knowing your plants comes into play. Some plants like a moist soil, some just want ta quick drink and then spend a long time in dry soil.
The good thing is that the watering is really the only thing you need to keep on top of if you get the soil and light sorted from the start.
So, can you overwater plants?
The answer is still yes, but you need to make sure that by watering less you aren’t papering over more serious cracks in your plant care.