Mexican fan palm trees are beautiful additions to anyone’s yard, but they can have problems.
One of the most common challenges with Mexican fan palms is when fronds, or leaves of the palm, turn yellow or even brown. This can be caused by overwatering, underwatering, a lack of nitrogen, transplant shock or pest attack.
This article will explore the top reasons why Mexican fan palms develop yellow fronds and what to do about it.
1. Overwatering
Overwatering can cause Mexican fan palm fronds to turn yellow. If you notice poor drainage in your soil or there is an unusual amount of rainfall overwatering can happen fast.
Overwatering is usually characterized by leaves that turn either yellow or brown before they dry up altogether. Too much water can cause root rot which is a fungus that damages the roots.
Reduce watering yourself if you are giving the plant too much. Make sure the soil drains well before planting your Mexican fan palm. Mix through organic material such as compost or aged cow to increase drainage.
Surround the palm with bark mulch to absorb excess rainfall. The water will be slowly released to the palms helping to reduce the amount of water reaching the roots.
2. Underwatering
If the tips of your Mexican fan palm leaves are turning brown, it’s likely being underwatered. Remember that palms like regular moisture and soil that is well draining.
If you have low rainfall or drought deep-water the tree instead. Use a hose or dripper system to deliver water to the roots deeply and less regularly.
Water the palm around 3 times per week deeply to help it to recover. You can also add some seaweed solution to help the roots to repair quicker.
3. Transplant Shock
When palms are first planted in your yard, just the shock of the transplant can cause the leaves to turn yellow or brown.
The good news is, there’s nothing you need to do because the problem always takes care of itself. Once the roots are established, the leaves should turn back to green again.
When you are moving your palm, aim to limit the amount of root disturbance. This will help it to recover faster and reduce damage to the tips of the roots. This is where the plant absorbs a large amount of water and nutrients.
Avoid giving the tree any fertilizer for the first two months while the roots are establishing themselves in the soil.
4. Diseases
If you notice stripes or spots of either brown or yellow, leaves that turn dark brown or reddish-brown, or yellowing that starts at the older leaves then spreads to the newer ones, your tree may have a bacteria or fungal disease.
Fungal diseases can be treated with a copper fungicide. Remove any excess palm fronds that are covered with spots or marks to minimize the fungal spores.
Avoid watering directly on the leaves to avoid spreading or encouraging fungal growth.
5. Lack of Nutrients
If you’re positive you’re watering the tree correctly, it could be experiencing a nutrient deficiency.
A deficiency in iron (yellow with green veins), nitrogen (yellow-green fronds), magnesium (bright yellow tips), or potassium (yellow spotting on older leaves) can cause yellowing leaves.
Iron deficiency can be treated with liquid iron chelates. If your plant is lacking nitrogen give it feed of nitrogen fertilizer with a high N-P-K ratio.
Use a balanced fertilizer if you are not sure what is affecting your plant. Most palms grow well with a balanced fertilizer once or twice a year.
Add pelleted chicken manure in spring for a great organic way to increase nitrogen and potassium levels.
6. Insect Infestation
Insects can attack your Mexican fan palms. The most common insects include mealy bugs, spider mites, and scale.
Most of these bugs are more inconvenient than dangerous, but nevertheless, getting rid of them with some insecticidal soap is a simple and very effective solution.
7. An Unexpected Cold Spell
Palm trees are made for warm weather, so if you suddenly get a bout of snow or very low temperatures, it can affect the leaves of the tree and cause them to turn different colors (usually brown, but occasionally yellow), droop, or wilt.
It might also cause the leaves to turn dark brown or even black before the leaves start to fall off of the tree altogether. The only thing you can do about this is give the tree some time to heal and protect it before the next cold spell.
8. Too Much Sun
Too much direct sun can affect all types of palm trees, causing the fronds to turn yellow and then colorless.
Prevent the situation by acclimating it to the sun a little bit at a time. You can set it in a shady spot and gradually increase the amount of sun it gets until it is used to the sun.
How Often Should I Water My Mexican Fan Palm?
Mexican fan palms like regular water with well-draining soil.
A brand-new palm should be watered daily, then decreased each week until it’s being watered two to three times every week.
During periods of extra rainfall, you can water the tree one to two times per week, and during drought times, you’ll likely have to water the tree more frequently.
Can Yellow Palm Fronds Turn Green Again?
Yellow palm fronds can turn green again if the cause of the problem is fixed.
Treat any nutrient deficiencies, pests and fungal problems.
If the tree has a nutrient deficiency, has been exposed to the cold, or isn’t used to the sunlight, just give it some time and the leaves should turn green again within a few months.
What Does an Overwatered Mexican Fan Palm Look Like?
An overwatered Mexican fan palm will have yellow or brown leaves that droop and a canopy that has a very droopy and saggy look. Discoloration usually happens first, then the sagging.
Should I Cut Off Yellow Palm Leaves?
Dead, brown or fungal infected leaves on a Mexican fan palm should be cut off.
Old leaves should only be removed once they become completely brown because if they are yellow, the leaves may still be receiving nutrients.
Also, only cut off the fronds from the bottom of the tree because if you remove the uppermost fronds, it might kill the tree.
Conclusion
Fronds that turn yellow on a Mexican fan palm tree signal something is wrong, but it isn’t necessarily something serious.
Some of these conditions are only temporary, while others can be permanent if something isn’t done about it quickly. If you’re not sure what to do, the best thing to do is check with the experts at your local gardening center.
I am an accredited practicing dietitian, experienced gardener and a dedicated cook. I love writing and sharing my experience so you can learn from my successes and mistakes.