RE: Watering in Summer

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-- a survey of landscape professionals and homeowners noted "drip irrigation" as the highest maintenance of irrigation systems; it requires constant monitoring.  Although some may find drip systems "easy", the numbers don't allow me to recommend it.

-- most maintenance people are not familiar with drip system repair and maintenance nor even simple scheduling – there are too many different systems.

-- and less familiar are home-owners.

-- for most efficient use, systems require pressure regulation (usually pressure reduction); a bit of information rarely shared at purchase.

-- often shoddy products.  (Yes, there are quality products available but that's not what people who are looking at "drip" as a cheap system are looking for.)

-- products are constantly being introduced, often disappearing after a few months; failed products and systems, hence, become hard to replace or impossible to find or repair.

-- small tubing often becomes clogged from hard water (although new designs include filters and self-flushing emitters (at a cost).  Obvisouly not a problem in the wodnerful-water areas of Northern California (where I used to live and have forgotten about).

-- the tubing is unsightly.

-- and because it's unsightly (granted, a subjective judgment), tubing is often covered by mulch or plant foliage, making it difficult to monitor the effectiveness of the system.  Most gardeners, amateur and professional, often aren't aware of a clog in the system or other maintenance issue until the affected plants begin to show signs of stress.

-- easy prey for wayward mowers and other garden tools

-- easy prey for kids and pets

-- easy prey for rodents

-- easy prey for vandalism.

-- provides no cooling effect during hot spells.

-- does not wash off foliage as do sprinklers.  As I said in an earlier message, getting water on foliage is a good thing.

-- the vast majority of our weeds in Mediterranean climates are cool-season weeds -- the kind that come up with winter rains.  Even with a drip system, we still get these cool-season weeds.

-- salt build up at perimeter of wetted area; such minerals aggravate most root-rot organisms.  Again, not a problem in the wodnerful-water areas of Northern California (where I used to live and have forgotten about).  Jan: I'm not sure of your research -- I haven't seen it -- but there's plenty of research that shows this salt issue and the connection to root rot.  And could it be that the water where I live is much harder than yours and that's why I see the salt build-up?

-- it’s often necessary to run it long to provide “deep” watering and consequently creates a long-term low-oxygen environment.

-- does not push oxygen into the soil.

-- Because the wetted area is much smaller when delivered by drip compared to sprinklers, control is more critical in application of water to avoid plant stress.

-- a recent evaluation of landscape drip irrigation systems revealed an average uniformity of less than 20% (> 70% is acceptable efficiency).

-- one peculiar disadvantage to drip systems: gardeners often replace plants that have died at the end of a drip system tube by placing a new plant in the exact same place as the existing tube end – regardless of the type, needs, or eventual size of the new plant.

And Jan, just because "drip" has become "standard" anywhere, doesn't make it effective nor appropriate. Many Claifornia cities are mandating it -- along with banning lawns.  It's popularity is primarily because it is easy to install -- as the ads state: anyone can do it.  Traditional irrigation systems required good planning, quite a bit of math, some engineering and a good deal of sweat.  Secondly, drip systems are now available in "popular level" packaging and are sold quite inexpensively; of course, these are the "cheap systems" I mentioned above.

Here's some bottom line -- although I have yet to see David's garden/landscape, I have seen many now-neglected or even abandoned gardens that were on drip and many that were on traitional irrigation. I can honestly tell you that those that were watered on drip would not end up on any magazine cover.

And in talking with many friends and associates who are contractors or actually in the irrigation business (including drip manufacturers) and still promote drip, all of them agree that drip has had and still has its issues and, they say, they're "now making them more like traditional irrigation systems". And I ask them, "Why not, then, use traditional irrigation systems"?

I suppose that all irrigation systems have their failings. I find that in 90% of the cases, it's "operator error".

Joe

From: david feix <davidfeix@yahoo.com>
Subject: Re: Watering in Summer
To: "Plant Forum Mediterranean" <medit-plants@ucdavis.edu>, thegardenguru@yahoo.com
Date: Sunday, July 19, 2009, 8:35 PM

While I find several points Joe states that make sense, I find the "tirade" against drip irrigation a bit too general in the points it makes to hold water.