Waiting for the rain

So the heat (over 40 C) continues, the serious bushfires continue and the weather bureau is forecasting "chance" of rain and "risk" of thunderstorms. I think that is just bureau spin for a few drops of rain, which unfortunately evaporates soon after landing. The drought drags on.

Without doubt the best way to deep water your garden is via natural heavy rain. However the continued dry conditions can cause soils to become hydrophobic (literally it means afraid of the water) which in physical terms it means that the soil gets a skin that repels water. How soils are affected depends on the soil type. In Melbourne the most sandy soils will quite quickly become hydrophobic, the surface affected with waxes from plants, air fall of hydrocarbons and oily polutants and possibly some natural near surface fungal and baterial actions. Melbourne more clay soils (>30% clay) areas will also be affect but only after the clay has started to dry out. First it becomes very hard, and then surface with start get powdery and large shrinkage cracks will open up. This occurs because the clays are loosing their formation water (water that makes up part of clays crystal structure). The fine powder particles of this dehydrated clay are then on the look out for water and will stick to water droplets rather than staying attached to other clay particles. The clay coated droplets soon coagulate and form a mat that forces any further water to run-off.(This drying of clays has the potentially to damage structures, like your house, via subsidence but this will need to be a separate post)

The best way to fix this in the long term is to add lots of organic matter to the soil to change its structure, and add a surface mulch.(when mulches are too thick and allowed to dry out they can apparently themselves become hydrophobic)

In the short term there is a group of materials called Surfactants (or wetting agents). They work by reducing surface tension of water, and are generally complex organic compounds which have one end which is water loving (hydrophilic) and the other water averse(hydrophobic), they work by acting as a joining agent. Soap and detergents are good surfactants, so using soapy grey water on areas that seem to be becoming hydrophobic has some merit as a good way to pre-wet the surface.(but the affect may only last a few hours).

Deep Watering : Method #3

Another good way to water deep and save water is to use a dripper system, and these are allowed under level 3 water restrictions. The best ones are pressurized and have the special dripper buried deep in the soil (20-30cm). They really require professional installation, and are therefore expensive. Right now in Melbourne there is also apparently a long waiting queue to get then installed.

The question I am interested in for now is is there a simple alternative (that works at low/normal pressure). Better still is there a way that I can just replace th heads on my existing "black pipe" sprinkler system. Sounds like a good excuse to visit Bunnings (a big hardware, home improvement and just about everything chain). Well the good news is there are several ways to do this, the bad news (for me) was most where sold out, only the most expensive fittings were left. So I ended up getting buying from the pope range rather than the nylex gardena range (which my system was mainly built from). I also got some repair plugs to temporarily seal some of the riser locations (I didn't want to remove them). Using the variable tricklers (pope Veri-Flow) has has the advantage that I can adjust the flow if individual. Now all I have to do is wait till my watering night, when I can test it out.

Deep Watering : Method #2

Our local Council, have long had the practice of adding about 30cm of flexiable tubing when they plant new street trees. They then come around every month of so on the trees first two summers and fill the pipe with water.

So this second method involves adding a pipe or other channel way to let you deliver water deep below the new developing roots when you do the planting. The same pipe can come in handy during dry spells. However trying to add pipe below existing plant may do more damage than good. If you buy plants in tubes (they are very economic to buy that way) a great thing to do is bury the tube (unfortunatey the tube pots are seldom longer than 10cm) right beside the plant as you are planting it, you can then fill this tube with water as the plant develops.

Deep Watering : Method #1

Deep watering can be very easy. For an area that yous don't want to dig over (eg around established shrubs) you can just get a garden stake, crowbar, or any strong and pointy and hammer it into the ground say 20 to 30cms around those things you wan to water deep. You can leave the whole open or put in some satur-aid or compost. Just make sure it fills up.

Some councils around melbourne are using an "air lance" (a compressed air operated probe, to do a similar job around established trees