Plant Troubleshooting – Yellowing Leaves & The Most Common Causes

Why do leaves turn yellow?

When we go to see our plants, we are used to seeing them green and full of vitality. So when the leaves curl, the plants sag or the leaves are yellowing, it is unsettling to say the least. It is easy to see that something is wrong, but it is not always as easy to figure out what is. Sometimes we need to try fixing different things to figure out what was wrong, and that’s okay. The important thing is that we try and that we keep trying.

Your plant’s leaves may be turning yellow for a number of reasons, and I will now go over the most common causes.

Seasonal changes

If it is nearing autumn where you are, and it is an outdoor plant, the leaves could be yellowing due to the leaf-shedding stage at the end of their growing cycle. If so, there is nothing to worry about. Enjoy the changing colours and the turn of the season.

Too much or too little water

If the leaves are turning yellow, there’s a good chance it has to do with the amount of water the plant has received. To test this theory, gently press your finger into the soil up the second knuckle. How does it feel? Is it dry? Then you should water it. Is it moist or even wet? Then it is best to let it dry before the next watering.

Container/growing medium with poor drainage

If the pot/container that you use has poor drainage, or the soil mixture does, then that can cause the plant to drown. We don’t want that. Some plants thrive off of wet conditions, but if the leaves are yellowing, chances are that your plant isn’t one of them. The leaves yellowing is one way the plant has to announce that something is wrong. It’s a cry for help.

Does the soil and container have good drainage?

If you’ve done the knuckle test and found the soil to be moist, it is time to check and see if how it drains. Should you suspect that it doesn’t drain well, you need to figure out why and then amend it. Have you used that soil mixture for other plants? If so, how are they doing? If they other plants are doing well, that’s a good sign the problem lies with your container. That is an easy fix. Figure out how many litres or gallons your plant will need, and then acquire a container with good drainage of that size.

However, if the plants that have the same soil mix aren’t doing well either, then it is time to reconsider your soil mix. If you have made it yourself, go over the ingredients and see if they counteract each other. Then look to what your plants need their soil mixture to be like.

Test your soil and then amend it to suit your plants. And if you purchased your soil mixture, I would suggest trying a different one and see how the plant reacts. I bought a slightly cheaper soil this year. I used most of it as a non-nutritious soil to mix with my own. But I did use some as is, and it did not drain as well as it should have. I won’t be buying that one again.

The soil has the wrong pH level for your plants

Figure out what your plants need in terms of pH and write it down. Do an at home soil test and see where your soil lies today. Adjust the soil’s pH and monitor the plant closely for a few weeks. See how it reacts and in a few weeks time, do the soil test again.

Issues with the roots

The leaves of a plant may turn yellow if a plant is experiencing root rot, if the roots are being attacked by pests in the soil – such as grubs – or if the plant doesn’t have enough room to grow. The leaves yellowing is like their way of telling us they’ve outgrown their pot and container and need more space to let their roots stretch. You can either re-pot them in a new container, or if you want to keep it at the current size, you can carefully wash and trim the roots.

Not enough nutrients in the soil

It isn’t enough to simply water a plant. Whether you grow the plant in soil, another medium or in water, nutrients need to be added to make sure the conditions meet the plant’s needs. When was the last time you fertilised the plant? Consider that it might be time to do it again, and to keep doing it at a closer frequency than you have in the past.

Conclusion:

I’ve found that yellowing leaves are generally caused by one of the issues mentioned in this article. And by finding out which issue is plaguing your plant, and fixing it, the leaves are likely to turn healthy once more. Some may fall off as the plant heals, but new ones will take their place.

If caught early, then the cry for help won’t be for naught. You’ll realise what’s wrong with your plant and you will fix the problem. You are the one who takes care of your plant. Trust that you know it well enough to know what it needs. And if you don’t, keep learning and keep observing. You’ll get the hang of it soon enough. People learn more from their mistakes than they do from their successes in life.

Good luck!