Lantana is one of the worst weeds in the world. In South Africa it requires landowners and landuser to prevent seed formation, spread and growth.
Lantana is vigorous and prolific grower. Man-made hybrids, bred in Europe have spread all over the world as a hardy, ornamental shrub, with multi-coloured flowers. It is dispersed primarily by fruit-eating birds.
The spread patterns is generally along fence lines and under trees, where it out-competes indigenous plants. Lantana form impenetrable, prickly thickets that reduce natural pasturage, productivity of cattle farming, access to water, biodiversity and land values.
The lantana's natural enemies are simply unable to stop the weed densifying and spreading.
To control lantana, very thorough and persistent mechanical plus chemical treatment is needed.
It is extremely difficult to kill lantana. The shrub is resistant to drought, frost, fire, insects, pathogens, browsing and herbicides – it dies back, but the parent plant coppices, seeds germinate (better in the sun) and the infestation becomes denser.
Initial Clearing: Cut the weed down to the ground, using loppers or a pruning saw, to remove nutrient reserves. Paint immediately, five times, with a herbicide. Registered herbicides: imazapyr (Chopper or Hatchet), picloram (Access or Browser) or fluroxypyr/picloram (Plenum). Preferably cut and paint when plants are growing actively.
Follow-up Treatment: Hand-pull or Spot-spray all weed regrowth when it is 0,5-1,0 m tall, using Access, Browser or Plenum. These herbicides are selective: they harm broadleaved plants, but not grasses. Avoid spraying non-target broadleaved plants such as indigenous plants and crops.
Annual Maintenance: Scout for weed regrowth every spring/early summer, and treat as immediately above.
Note: animals suffer secondary photosensitization due to liver poisoning by lantana
Lantana is in Category 1b. This category requires a coherent response and maintained gains in the control of these invaders. Measures must prevent the plant from forming seed, regenerating or re-establishing itself in any way.