An example of how to use chemicals responsibly

The following is a response from Ian the Editor of a well-known horticultural industry newsletter to a reader, Annette of Mackay, Queensland. Annette plans on using a herbicide to get rid of a large number of small, vigorously-growing lantana plants (Lantana camara). She wants to know how this can be done without killing wanted plants or polluting a nearby creek.

Excerpt from newsletter

Well, Annette, before I use any chemical, whether it is a herbicide, fungicide or pesticide, I ask myself.

As you probably know, chemicals are toxic and can have a long-term effect on the environment.

A photo of chemical containers. Choosing the right chemical for the job means knowing what chemicals are available and how they differ. That is why it is important for you to read each label properly. Look for information about the chemical's use, how you would apply it, use-by date, safety precautions, required personal protective equipment, and how toxic it is. You should also read the material safety data sheet (MSDS).

To answer your first question, you need to find out if the chemical has a broad-spectrum or specific use - that is, will it kill everything it comes in contact with, or has it been developed to kill just specific weeds or pests. You should be able to find this information out from either the label or the retailer who sells you the chemical.

In the case of plants, you must also know the habit (for example, are they large, woody shrubs or small, soft plants?) and its stage of growth - chemical herbicides, for instance, work best on young, actively-growing weeds.

Okay, that's a start. Now for your second question.

There are two points for you to consider here:

  1. How will you apply the chemical?
  2. How do you minimise non-target damage?

A photo of someone painting a chemical on a plant. The first point will be answered by looking at the label and following the manufacturer's instructions. Make sure you know how to apply the chemical using the recommended methods. This is necessary from the OHS perspective and for minimising damage to non-target plants, the second point.

I will run through what I would do with your lantana problem, Annette, to illustrate what I have covered so far.

Photo of lantana.Lantana is a woody shrub that can be sprayed if actively growing and less than two metres high. As there is a creek nearby I would choose an herbicide like Roundup® Biactive.