Monstera plants are usually pretty tough, but sometimes they can surprise you with sudden symptoms like brown spots or yellowing leaves. If your Swiss Cheese Plant starts looking a little under the weather, it’s time to play plant detective. While it might just be a watering issue, there’s a chance your green friend is dealing with an actual disease.
Keep an Eye Out for Brown Spots and Discoloration
If you notice brown spots with a distinct light-colored “halo” popping up out of nowhere—and they seem to be spreading across the leaf or jumping to other leaves—you might be dealing with Eye Spot Disease. This is caused by a fungal pathogen called *Spilocaea oleagina*. If you spot these “eyes” on your Monstera, here’s your game plan to get it healthy again:
- Grab your shears and prune off any infected leaves immediately. Toss them in the trash (not the compost!) to stop the spread. Often, a quick pruning is all it takes to save the plant.
- If the spots keep coming back, you’ll need to bring in the big guns with a fungicide. Look for a copper-based treatment to get the fungus under control.
- To give your plant’s “immune system” a boost, try adding some liverwort extract or a horsetail tea soak to your watering routine.
When It’s Not a Disease: Common Care Mistakes
If your Monstera’s leaves are turning yellow, it’s usually a cry for help regarding its environment rather than a disease. Take a quick look at your watering and feeding schedule to see where you can make some tweaks.
Yellow leaves are often a sign of a nutrient deficiency. To keep it happy, use a liquid fertilizer every two weeks during the summer and dial it back to every six weeks in the winter. If the root ball feels bone-dry, give it a good soak in the sink so the soil can fully rehydrate. On the flip side, watch out for “wet feet”—standing water is a no-go. If the soil is soggy, you might need to repot it in fresh, well-draining mix. Pro tip: Always water and mist your Monstera with filtered or lime-free water if possible.
Lastly, don’t forget about the sun! Yellow patches can also be a sign of sunburn. If your plant is getting hit by harsh, direct rays, it’s time to find a new spot for it or hang up some sheer curtains to filter that light.
