Within the Verbenaceae family, only the 150 or so lantana species have earned the nickname of shrub verdana.
Alongside its numerous varieties, hybrids, and cultivars, lantanas are highly prized for easy care and heavy blooms.
They are generally smaller than verdanas. They’re often grown indoors or even as annuals in cooler climates.
However, every plant gets sick from time to time, and yellowing leaves are part of a plant’s language that signals something may be wrong.
Why is My Lantana Leaves Turning Yellow?
There are numerous reasons for yellow leaves on Lantana plants, but most are easy to diagnose and treat.
From early dormancy to improper care or serious disease, some of the most common causes and solutions are here.
Boytris blight is a serious fungal infection that gets worse if you overwater or it’s exposed to excess moisture.
Not only will the Lantana plant leaves turn yellow, but both foliage and flowers will begin to rot and your lantana will stop flowering.
Try to prune away any infected parts. Be careful to use sterile shears and avoid contact with healthy parts of the plant.
If there is no improvement or the problem spreads, you will have to sacrifice the entire plant to prevent nearby plants from being infected.
Lantanas are tropical perennials, although they’re sometimes grown as an annual.
When exposed to cold temperatures, your plant may think it’s time to go dormant.
In established perennials, this symptom will generally go away on its own if warm weather returns, although young plants or those grown as annuals may start to die if not provided warmth in time.
As with most tropical plants, lantanas need bright, indirect sunlight.
Too much sun can lead to scorching, and too little may cause the leaves to turn yellow.
To diagnose, keep an eye on the plant for a day or two and keep track of how long it’s in the shade.
A little shade at midday is okay if it’s getting full sun in the morning or evening, as is dappled sunlight.
However, if you find the lantana isn’t getting at least 6 to 8 hours of sun, it may need to be moved.
Infestations and Secondary Infections
Piercing bugs such as aphids and spider mites during the sap from your plants tend to hide on the undersides of leaves.
This can often lead to upward curling Lantana leaves and yellow spots or edges as they drink.
Even worse, their frass, known as honeydew, can invite fungal infections such as sooty mold that also cause leaves to develop yellow or brown patches.
A few species may also be vectors for bacterial or viral diseases that might be incurable or spread to other plants.
The two easiest ways to deal with infestations (and even many secondary infections) involve neem oil.
Need foliar sprays will kill on direct contact, suffocating the bugs and destroying many species of a fungal spore.
Meanwhile, neem soil soaks are a systemic remedy that lasts 22 days.
It kills more slowly but can also protect the plant from many internal infections and is highly effective.
Soil soaks may be applied every 2 to 3 weeks as a preventative, while the foliar sprays are usually used every 14 days for prevention.
Natural predators such as lacewings, ladybugs, and parasitic wasps are also highly effective. However, you will have to deal with any ants present (ants will defend piercing bugs in exchange for harvesting the honeydew as a food source).
This is a drought-tolerant genus, so exposing lantana to too much water (or having poor drainage) can easily lead to root rot.
Two early symptoms of this deadly disease are yellowing and upward curving leaves.
If caught early enough, root rot may be treated, usually by pruning away the diseased roots and planting in fresh, dry soil.
Even if root rot hasn’t set in, soggy soil is a sign of overwatering. Slight yellowing of the leaves may accompany that.
Allow the soil to dry out and follow the soak-and-dry method when watering.
This method is quite easy:
- Stick your finger in the pot
- Water if the soil is dry 1″ to 2″ inches down.
For in-ground lantanas, water when the top of the soil is dry to the touch.
In both cases, water slowly and evenly until the water seeps from the bottom of the container or you’ve given your grounded plant approximately 1″ inch of water.
Consider amending the soil with perlite or another aggregate to help prevent compacting and improve drainage.
A Final, Natural Cause
In the event someone gave you common lantana without telling you what it is, you might be surprised to see yellow streaking or marks as it grows.
Many species and cultivars have natural variegation, which may be more or less apparent depending on the growing conditions.
If you have unidentified lantana and are seeing yellow markings that have no apparent cause, take a photo and check for a match on a website or plant identification app.
There’s a good chance you have a variegated plant and can safely enjoy the yellow markings.