Lantanas the yellow ones

Question

Why and what to do when beginning to bloom the blooms get black and the blooms are half yellow and half black

Answer 1

Check the soil moisture. Make sure the soil is well draining.
Root rot could cause the flowers to darken and die.

This article will refresh you on the care requirements.

https://www.gardeningknowhow.com/ornamental/flowers/lantana/lantana-plants.htm