is the way to determine irrigation uniformity and precipitation rate.
It should be done for a timed duration under typical wind speeds and
with numerous cups.
How little water does it take to keep St. Augustinegrass alive?
A: Very little, about 43 inches per year, which is much less than
the 60 inches we get in rain. ("Water
requirement for St. Augustinegrass")
Q: So what's the problem?
A: In South Florida, from March to May, there's less rain each
month than the turf needs to stay green.
Q: How much water does
it take to keep St. Augustinegrass green?
A: In a typical year the lawn needs about 3, 4, and 6 irrigation
events in March, April, and May, at 3/4 inch each. If it doesn't rain
a drop, the turf needs about 5, 6, and 7 irrigation events, respectively.
The rest of the year the lawn can get by with 2 irrigations per month
because there's plenty of rain, and in December and January it's cool
enough that we might not need to water at all.
Q: Is this true everywhere?
A: No. This is based
on well drained level areas near the water table. In urbanized Miami-Dade
and Broward Counties, the water table averages 4.5 feet depth, which is
close enough for some moisture to wick up through the rock to the turf
roots. Some areas are wetter or more protected by shade, while the coastal
ridges, hill mounds, and areas near the pavement and near the prevailing
winds tend to dry out faster. ("Contour
of water elevation")
Q: If the turf doesn't
get watered, will it die?
A: Yes, eventually St. Augustinegrass will die. Let's say it doesn't
rain a drop, and the turf starts to wilt in the late afternoon, but it
looks okay in the morning. ("Killing
the lawn"). Within about 7 days the turf will continue
to be wilted in the afternoon, but when you look at it in the morning,
it hasn't recovered, and it's remained wilted all night and all the next
day. Now you've got about 7 days before the lawn is dead brown.
Q: Only fourteen days
doesn't sound very safe.
A: It's very likely that there will be some rain.
Q: What about spraying
the turf with an antitranspirant or putting some superflexology geewhizmo
polymeric soil body conditioner to the soil?
A: It's your money. Why don't you just put the money in the soil?
More seriously, plants have been at the business of growing for several
hundred millions of years. They haven't figured out how to grow and exchange
carbon dioxide without losing water at a comparable rate. Those two compounds
have the same diffusion properties, and there are no synthetic materials
that can change the basic physics. Also, the turfgrass has essentially
no internal resistance to water exchange. It acts as a soda straw, driven
to lose water based on the heat energy from the sun. When you heat a pot
of water, the water converts to a gas. When the sun shines on the leaf,
the water converts to a gas. Same process. ("Drought
Resistance and Landscape Water Conservation")
Q: What about the irrigation
system? If we only have a few hours per week to irrigate, shouldn't we
make those hours count?
A: Right. Irrigation systems tend to be poor in distribution, and
this is corrupted by wind. A thorough audit of your sprinkler system will
reveal some things you can improve. Also, Try not to water when the wind
is blowing strong, say, more than about 5 miles per hour. ("Coping
with Watering Restrictions")
Fix your sprinkler system .
. . so you can shut it off!
Valve boxes http://www.floridaturf.com/valvebo.htm
How not to ditch
Water requirement for St. Augustinegrass
(part 1 of 2): How much?
Water (part 2 of 2) Killing
This two-part series describes the normal process of water use by turfgrass,
and how many days it takes to kill a lawn by not watering it.
Irrigation Conservation in
Best Management Practices (BMPs)
An Opinion Essay
Basically, you can't have your cake and eat it, too. An attempt to dispel
common irrigation myths. With associated slide show:
Lots of water but seasonal
A photo-illustrated guide
Jess Stryker's Free Irrigation
Tutorials! Many excellent articles on irrigation.
Irrigation Industry Links
WWW-Virtual Library IRRIGATION. Quite a few good links.
of Irrigation Systems Used in Florida Nurseries.
Uniformity - Center for Irrigation Technology Irrigation Notes.
Systems Slideshow - New Mexico State University.
The Irrigation Association.
The national trade association. There is a directory of certified
Irrigation & Green Industry Network. Go to the irrigation section
Texas Turf Irrigation Association
Code of Ethics - some great ideas.
Software Republic Landscape
design software and irrigation design software. RainCAD appears to be
a useful program; shareware downloads.
Rain Bird - Irrigation Manufacturers,
Sprinklers, Products, Landscape Systems Rainbird is one of the other
Spears Manufacturing Co. Plastic pipe fittings and valves.
SprinklerSpot - purchase online.
TORO: Golf Course Management. Toro's main irrigation page
Toro Residential / Commercial Irrigation. Toro's landscape irrigation
Weathermatic - Homeowner information, but no retail sales.
Turf Bubbler Wick Irrigation -- The Evolution Begins! An example
of an alternative system, which is neither subsurface nor overhead.
Valve Boxes, Valvebox, Irrigation Valve Box, Meter Boxes, Electrical Boxes
Made By AEP Valvebox. Valve boxes are one of the often-overlooked essentials.
- not a time clock, "not rocket science, or maybe it is."
Device upgrades existing sprinkler timer to adjust for relative humidity,
wind, and temperature. Like a miniature weather station but apparently
does not measure rainfall.
Barry Edwards Irrigation -
excellent photos of installations.
Choate, Richard B. 1994. Turf
Irrigation Manual. Weather-matic Division of TELSCO INDUSTRIES, Dallas,
Pair, Claude H. (ed.) 1983.
Irrigation. The Irrigation Association. Arlington, VA.
Pira, E. S. 1997. A guide to
golf course irrigation system design and drainage. Ann Arbor Press, Inc.
Sarsfield, A. C. 1966. The
abc's of lawn sprinkler systems. Irrigation technical services. Lafayette,