Ask Mr. Smarty Plants

Lantana urticoides (West Indian shrubverbena) and Lantana camara (lantana) are the native forms that are most likely to be growing in this area. However, it is more likely that what you have in your garden is a commercially named cultivar, hybridized for bloom type or color. Hybridizing will often change the basic nature of the plant to the extent that it no longer has some of the qualities of the true native, such as resistance to disease or adaptability to poor soils. That is why we at the Lady Bird Johnson Wildflower Center urge the use of native plants in our landscaping.

However, we can tell you some of the problems that lantanas can encounter, and perhaps one of them will answer your question. Poor blooming in the lantana is usually due to too much shade or excessive fertilization. You live in the Austin area and have experienced the same cool, wet two months of the summer as we have, but if your other lantanas are blooming all right, the weather probably isn't the problem. If, however, this particular plant is too shaded by a building or other plants, that could cause a number of different problems. Powdery mildew often occurs on lantanas grown in too much shade. If the plant is in an area poorly drained or watered too frequently it can develop root rot. Excessive fertilization may reduce flowering and make plants more susceptible to disease.

Now, how about varmints? Lantana lace bugs can cause leaves to appear stippled or to brown and drop. Sooty mold, causing a blackish discoloration on the leaves, is usually caused by an infestation of whiteflies.

If it turns out the location, shade, drainage, etc. are the causes of your plant's woes, it probably should be removed. It wouldn't be advisable to transplant it to some other location where mildew or insects might move to healthy plants. If you want to try to give it another chance where it is, and if there is enough sun there, remember that during the bloom period the lantana needs a thorough watering once a week if it hasn't rained an inch or so that week. Try to avoid watering from overhead, as with a sprinkler, as this can also contribute to the mold problems. You might also try trimming it back as much as a third; water and fertilize the newly cut back plant and, hopefully, it will return to bloom quickly.

Lantana urticoides

Lantana camara