The Australian Bureau of Meteorology has today announced the
next three months across the East and North of Australia will be drier and
warmer than normal.
That means a strong likelihood of your turf areas needing
more irrigation than usual. Your turf
might be stressed. How can you best handle
the issues that arise?
Adequate potassium fertiliser is a wise option. Potassium boosts stress response in plants as
it helps develop better structural tissues, including cell walls, and aids plants
in overcoming or being resistant to water stress, as well as the related heat
stresses, even in those varieties with superior heat adaptation.
Use a fertiliser mix with adequate potassium, applied soon,
or add up to 1-2 kg / 100 sq m of
potassium sulfate or even potassium nitrate as the fertiliser. You may need to
look more widely for these but they are around. Slow release NPK mixes tend to
use one or other of these products, but you want a potash content of around
10-15% in the mix. Avoid muriate of
potash which is potassium chloride, as it can add saltiness to your turf
area. Muriate of potash is readily
available, and can be cheap, but it a short term gain that can add to long term
problems.
And what about the perennial issue of mowing?
There is a tendency to mow the lawn shorter in warm weather……..as
if you might be able to avoid an extra cut by doing that.
Reality is you are best to actually cut the lawn less
frequently and slightly higher, when there is hot, dry, stressing weather! Long leaf that is uncut means less water loss
from the cut edges and better soil cover from the leaves that helps control
soil temperature and lower water loss from both evaporation and transpiration. When weather turns and some decent rain
arrives, then you could mow at a lower height………but not too low unless you have
a very strong need for a “golf green” appearance, and the mower is suitable.
Zoysia is well adapted to hot weather, and can easily adapt
to mowing heights between 15 – 60mm. It
is suggested that heights of 35 – 45mm [possibly slightly more] are suitable
when the weather is hot and dry. Switch
to a lower cut height [around 20-25mm] once more regular rain is imminent. Always remember that you do not want to
remove more than one third of the sward height at any one mowing.
It is better to manage your turf and even avoid too much
mowing. You can achieve a good quality zoysia
turf with maybe 50% of the water demand [ currently up to 50% of the 6-8mm a
day of evapo-transpiration in Darwin] applied on every second or third day]
especially if the turf has good soil cover.
Would you prefer mowing weekly or every three or four weeks? It can be done to manage water, fertiliser
and mow frequency to achieve a good turf that is functional and looks good, and
is mown at 4 week intervals [ but check for weeds too].
You want your turf to develop a deep strong root system that
can access water from up to around 150mm [ or more] deep in the soil profile,
and not the shallow 25mm deep roots promoted by short watering that only superficially
wets the profile to 25 – 40mm.
 |
| Infrequently mown zoysia as a median strip in Kuala Lumpur Malaysia |
Longer, less
frequent irrigation is definitely superior and aids developing a robust root
system that can be functionally efficient in scavenging water.
