Gone are the days when one could leave the earth bare, pull out the weeds and about the extra water needed to keep things alive. And that’s really what summer gardening in extreme temperatures is all about--getting plants through the rough times so that when the weather is a bit kinder they can go about the business of growth and reproduction. In the harshest of environments, one can pretty much forget growing any vegetables - except for the heat-loving ones, such as members of the melon family.

For the moment, it is best to focus on “what” to use, and save the “why” for a later article. Anything that is organic material (that is, made up of carbon, oxygen and hydrogen) can be used as mulch, but there are a few more “socially acceptable” mulches.

Ground bark (as fine as possible, depending on cost) is the most popular, and most natural looking mulch available. Whenever possible, recycle trees that have been cut down, as this goes part way to rationalising our actions Straws and hay are great, but provide shorter-term moisture barriers. In particular lucerne, or alfalfa, hay is excellent for heavy feeders like roses or camellias, because of the high nitrogen and potassium available. Composted sawdust (be careful of phytotoxins in the bark) is a great initial dressing for gardens. Follow it with bark; this mixed with sand makes an unbeatable lawn topdressing! Compost is great for vegetables or any special ornamentals, but the length of time needed to produce it makes it a valuable commodity. And then, of course, recycled newspapers, old clothes and blankets, carpets … anything that is organic, can be effective, although it takes a bit more courage to use these, as this is not entirely acceptable in mainstream gardening.

Anything that covers the surface, lowers the temperature and prevents competitive weed growth is considered mulch. Even gravels, pebbles and so forth will keep the soil cool. Try it on a little uncovered patch on a hot day, and see how much cooler the mulched area is than the ambient ground or air.