What's it look like?

Scale insects are tiny creatures that are often undetectable to the human eye, but can be noticed by the protective coating that they produce. These coatings are mostly small white or brown circles. The insects produce a sugary honeydew that allows sooty mould fungus to grow on it. Often it is the blackened stems of the sooty mould that is seen before the scale. Ants are also commonly associated with it too.

What it attacks

White scale attacks a range of plants including citrus, roses, houseplants, camellia, berries and ferns. Brown scale is common on citrus. You'll find the scale on the leaf midrib or on the stems and branches. For clumping plants, look for evidence of the scales at the base of the clump. Scale insects suck the sap from the plant and will generally weaken the entire plant. If not treated then it can stunt growth and eventually kill the plant.

What to do before it arrives

Splash plants with diluted soapy water as this can sometimes deter the insect from laying eggs.

What to do if you already have problems

If you only have a few scales then they can be scraped off with your fingernail. You can also try hosing some off with water if they haven't been there for too long. The longer the scale has been there it will attach itself harder. Otherwise use soapy water or white oil up to 2 or 3 times if it has become a real problem. Make sure that the oil is applied liberally to cover all traces. After the scale has been treated hose off the remaining honeydew to get rid of the sooty mould as well. Make sure that conditions aren't kept too dry which encourages ants and can make the problem worse.