In the wonderful world of houseplants, there’s a lot of variety to choose from. For many, the perfect choice is the rubber tree (Ficus elastic).
This wonderful plant is easier to grow than its relative, the fiddle leaf fig (Ficus lyrata), and can bring a wonderful touch to any room.
However, rubber plants are native to the tropical rainforest, so if you don’t get the basics down, there’s a chance you’ll run into problems down the road.
The rubber plant can tell you when something’s wrong, but it has a limited vocabulary, meaning you’ll often have to narrow down the problem based on the symptoms and a little detective work.
One of the more common symptoms is the appearance of yellow leaves, often an early warning sign that your plant is headed for major problems.
Causes Of Yellow Leaves On Rubber Plant
The good news is that yellow leaves don’t spell the end for your Ficus, and most causes are simply tweaking your care regimen slightly.
Here are the six most common causes of yellow leaves and how to fix each one.
Leaf With Old Age
Sometimes, there’s not actually a problem at all. Such is sometimes the case when lower leaves begin to turn yellow.
This is because the rubber plant grows upwards, sprouting new growth from the top while older leaves remain below.
As a result, the odd lower leaf may start to turn yellow simply from old age.
This is where it suddenly gets more complicated, as yellow leaves can indicate overwatering OR underwatering, depending on a few key factors.
Overwatering may be caused by poor drainage, compacted soil, or bad watering habits, and the yellowing will usually be accompanied by mushy leaves or edema.
Edema is a condition where the leaves form water blisters that eventually burst, leaving behind brown spots ringed in yellow.
To fix this problem, do the following:
- Ensure your plant is in a container with adequate drainage holes.
- When watering, don’t go by a calendar (this almost always leads to excess water in the pot), but instead use the soak and dry method to ensure proper watering and water when the soil is dry 2″ to 3″ inches down.
- You may need to transplant a severely overwatered rubber plant to a new pot with fresh potting mix, checking for signs of root rot when you do.
Underwatering is a little more complicated because the symptoms may not actually mean you’re not giving the plant enough water.
The yellowing occurs on the lower leaves first, which can lead to thinking it’s an age-related issue if you don’t check the soil.
When a houseplant has been overwatered, it can develop root rot, a condition in which the roots are slowly destroyed, preventing the plant from absorbing water and nutrients.
This makes it look like the plant isn’t given enough water, so ensure the soil is dry before trying to compensate.
Piercing insects such as aphids and mealybugs are common houseplant pests that drink the sap from your plant’s leaves.
Large infestations can turn the leaves yellow by draining the chlorophyll out, leaving behind yellow spotting.
To verify this as the cause, check your leaves for any signs of pests, especially on the undersides.
If you confirm an infestation, you can treat it using a neem soil soak, neem foliar spray, or an insecticide designated for use against that particular pest.
As mentioned earlier, root rot is a nasty disease caused by overwatering that can mimic underwatering symptoms.
Root rot can be identified by brown or black, mushy roots that often give off a rotten smell.
When you see this problem, you’ll have to remove the diseased roots with a sharp, sterile knife, sterilize the remaining roots in a bleach solution, then replant them in brand new soil and a new container.
This causes the same yellowing symptoms as underwatering and root rot because the roots are so cramped they can’t effectively absorb water and nutrients.
You’ll know the tree is rootbound if you see roots poking out the drainage holes or above the soil surface.
Fixing is a simple matter of repotting the ficus into a larger container.
Sudden Environmental Changes
Finally, we have a couple of issues that all work together.
Rubber trees don’t like sudden changes, so a major temperature shift, especially outside their ideal 60° and 77° degrees Fahrenheit range, can leave the leaves yellowing out of stress.
This also applies to humidity drops, and you may even get a slight yellowing from transplant stress.
However, it’s also possible the problem is a sudden change in lighting.
Your rubber tree needs bright, indirect light and can scorch in direct sunlight, which can cause some yellowing.
At the other end of the coin, insufficient light may cause some leaves to die, producing yellowing.
Finally, moving your rubber tree to or from bright light too suddenly can cause yellow leaves from stress.
When moving your plant to ensure proper lighting, first consider whether the change will be drastic.
If the answer is yes, you’ll need to harden the plant by moving it closer to the window or light source a little bit at a time.
Otherwise, it’s similar to walking from a totally dark room into a brightly lit one – in other words, it’s sometimes painful and never pleasant.