Anita Morton - Growing Gardens
With the natural rainfall most of us have been lucky enough to get, all our gardens should be moist and thriving. As we head into what are generally the warmest and driest months of the gardening year, it pays to give some thought to locking that water into the soil mulching in other words.
Organic mulches range from coarse, chunky and nearly indestructible pine bark through to soft products like lucerne hay and tea tree waste. The soft mulches break down very quickly when in contact with moist earth, making them valuable to those who are trying to garden on poor, compacted or sandy soils. The organic matter liberated by the mulchs decay feeds worms and other soil organisms, greatly increasing their numbers and hence beneficial activity. A drawback to soft mulches is the frequency with which they have to be topped up.
Coarser mulches like forest fines, shredded garden waste and the like will also eventually break down, but the process is slower. An important fact to take note of is that all fresh woody mulches need to be partially composted before they go onto the garden. If youre having a tree taken down and chipped, you need to pile up the material in a heap and leave it for a few weeks until the heat of decomposition dies down. Spread it once it cools.
A mixture which contains a lot of carbon (such as wood chips) will draw down nitrogen from the soil as it begins to break down. This sometimes leads to sickly, yellowing plants surrounded by a blanket of happily rotting mulch. If you have this problem, its easily solved by dissolving some urea or sulphate of ammonia (nitrogen) in water and spraying it over the mulch. Water in well afterwards to wash it down into the soil.