|
Watering
Gardens Efficiently
Much of the material in the pages of other crops will apply
to gardens. When you consider an irrigation system for your
garden it is important to realise that if you water too much
you can kill some plants, waste water and expensive nutrients,
while too little will kill some other species. So you need
to understand the needs of your particular soils and plants.
Trees
and Shrubs:
If you water to an optimum for growth then you will need
to spend more on fertilisers to 'feed' this growth. On the
other hand it is quite possible to water much less, but still
enough to keep the plants looking healthy. They will put on
less growth, which will reduce pruning costs and use considerably
less water and fertiliser. Of course, while a garden is 'young'
you may well want to have maximum growth for a few years to
reach the 'mature' look quickly. The amount and frequency
of watering will vary considerably between species and on
different soil types.
Grass:
How perfect do you want your grass? It is possible to water
in such a way that the grass will stay green, while growing
much slower, reducing mowing time and all related costs. If
your soil is water logged then the grass will have very limited
roots and will needs watering much more often than if it has
deep healthy roots. Drainage is essential in heavier soils.
Only water when the grass is beginning to suffer visibly and
then water with quite a lot.* You should use a raingauge to
measure what you are applying.
*As
an example: You soil may hold 100mm of water in the top 30cm
when it is 'full'. The grass will use water in relation to
the weather conditions ( a lot on a hot windy day and little
on a cold dull still day). After your grass has used about
50mm (10 days at 5mm per day in the height of summer) the
rate of water use will slow as less becomes easily available.
Within a few days the grass will start to show signs of 'stress'
- you will learn where this generally occurs and use that
as the 'trigger' to start irrigating. (The Waterwatcher
will do this for you automatically once you have set it).
If you then apply 5mm only, the water will not be enough to
soak into the soil to any depth and most of it will evaporate
from the surface very quickly, leaving the grass under 'stress'.
Remember:
Water goes into the soil like a 'wine glass pyramid' and
therefore to re-wet the soil to 30cm will need a lot of water.
However, when you have applied a lot of water the grass will
not need any more for some time.
Irrigation
Systems - Sprinklers: A permanent system of sprinklers
should be installed to a suitable design to cover all areas.
This can then be used as and when necessary. But, if the system
is badly designed and does not cover all areas equally, it
is common for people to water far too much in some parts of
the garden to overcome the bad layout. However, watering overhead
will waste water (so always water at night if possible) and
will leave the grass wet, which you may not want.
Drip\Trickle\Seep
hose etc:
The most efficient system is to use drip. This is a plastic
pipe with nozzles, laid out permanently in the garden. It
is better to bury it, but then you must beware when digging!
It is possible then to water some parts more than others and
even to apply 'feed' through the system. It should be controlled
by a timer for convenience. If you wish to have more advice
please email: peterwhitewater@irrigationworld2000.com
|
