Re: Drip Irrigation

Yes I would like to see your pictures on Face Book but I must be your friend to do so. Well, I suppose so. 

Chantal Guiraud
Montpellier, France



Le 18 août 09 à 00:56, Margaret Nottle a écrit :
Check out my Face Book pages for a hundred or so Med plants growing and 
flowering now in our garden.

Trevor N.

-----Original Message-----
From: owner-medit-plants@ucdavis.edu [mailto:owner-medit- plants@ucdavis.edu] 
On Behalf Of Pamela Steele
Sent: Saturday, 15 August 2009 5:47 AM
To: margn@internode.on.net; sean@gimcw.org; medit-plants@ucdavis.edu
Subject: RE: Drip Irrigation



Thank you Trevor
Everything you said makes so much sense. ...... I gotta get some of that 
discipline!!

Pamela
-----Original Message-----
From: owner-medit-plants@ucdavis.edu
[o*@ucdavis.edu]On Behalf Of Margaret Nottle
Sent: 14 August 2009 00:53
To: sean@gimcw.org; medit-plants@ucdavis.edu
Subject: RE: Drip Irrigation
Can I butt in here please? I/ We do try very hard to garden without any 
watering over summer - 5 months of hot and very dry weather + high
evaporation and transpiration rates from December until the end of April. The only exceptions are new plants that need to get established in a garden filled with established competing plants, and our pot plant collection at out front door and around the back door. I think we are pretty happy with 
the result tho' we don't have the usual flower-filled summer an
Anglo-heritage suggests is the essence of summer. Instead we have a quiet 
summer garden that is 'at rest' (tho' not dead).
Discipline? Yes, but it's not that hard if you can adjust psychologically to the changed pattern and rhythm of the seasons implied by the above reversal to the 'norm'. There are, after all, millions of summer-dry/ winter- wet plants to choose from. The difference lies in how they are sourced - from seed collectors, specialist growers and collectors, plant nuts and rarely from the big retail outlets filled with flowering plants trucked in from 
somewhere else. Takes more patience to track things down and to raise
seedlings to maturity and there's less opportunity for the fun of impulse 
buying and self indulgence when you 'really shouldn't'.
There's also a change in the way garden tasks are done: everything planted bare rooted in winter when its wet; no planting after the rains stop; no 
flowering roses popped in in mid-summer; much less emphasis on summer
flowers and much more emphasis on flowers that bloom in autumn, winter and 
spring.
There's some new research just out from the Arboretum at Waite Institute that shows very well the importance of washing off all the soil- less soil from trees planted out from pots and planting, in effect, a bare rooted plant into the native soil of your site. Those fake soils are like sinks of death for plants when they dry out so avoid the trap and wash plant roots free of it. Then you can also check root systems for cork-screws and deal 
with them before you plant.

Cheers

Trevor N
PS Think of allthe great Classic garden styles - Roman, Moorish, Italian, Chinese that were developed solely on what fell out of the sky. History 
ought to be informing our understanding of gardening where we live.

-----Original Message-----
From: owner-medit-plants@ucdavis.edu [mailto:owner-medit- plants@ucdavis.edu] 
On Behalf Of Sean A. O'Hara
Sent: Thursday, 13 August 2009 5:07 AM
To: medit-plants@ucdavis.edu
Subject: Re: Drip Irrigation

Hi David, Joe -

Irrigation is always a very complex topic.  Your statements are
correct that there is no one-time installation solution.  Gardens
change continually.

Some personal observations are:
- too often far too little water is delivered to frequently
- an un-watered garden is seldom considered possible

The former is subject to soil conditions, which of course vary from
location to location.  Frequently, our local clay soils are too
compacted from construction or other urban activities and this is
not re-mediated.  Plants end up growing in only the top layers of
soil because of this, exacerbated by frequent low-volume irrigation
that never penetrated deeply.

The latter requires careful plant selection (as opposed to whatever
I fancy or whatever the nursery offers me) and planting when
moisture is available and temps are cooler (with the fall rains).
It also requires discipline - some plants may fail (and it is
tempting to rush out and 'save' them with irrigation).  But plants
grown in this way are forced to find their moisture as they do in
the wild, and do this they can!  Growth is slower, more sturdy, root
systems are deeper and better able to get through dry periods.
Overall, this 'lean and mean' approach leads to a healthier plant
(just as humans also benefit).  Because water has been so cheap and
generally plentiful here in CA (water restrictions are rare) it is
hardly surprising that the 'dry garden' approach so rarely employed
(intentionally), even with native CA plantings.

At least of combination of the above two points could be employed to
help mitigate the growing realization locally that current practices
are not sustainable (CA is running short of water to support its
every increasing population) nor even preferable (plants grow better
when chosen and placed appropriately and their needs provided in a
more natural manner).

Regards,
Seán O.

Seán A. O'Hara
sean (at) gimcw (dot) org
www.hortulus-aptus.com


Thanks for the clarification on type of heads used with your
recommended conventional irrigation systems.  I guess I am in a
picky mood these days, but  couple of constraints on the usefulness
of these types of irrigation still make me feel that they aren't
always the most useful.  Even stream rotor heads are subject to wind
drift and being blocked by shrub/plant growth, and still lead to
broad areas being watered that may not necessarily need watering,
and also it does encourage more surface weed growth as well.  I find
bubblers/flooders work well enough with flat sites or soils that can
absorb more water more quickly, but on slopes with heavy clay, or
extremely sandy soils, not so much.  I guess I just have become more
accustomed to using drip almost entirely for new landscapes, and
prefer the lack of trenching for piping, especially when dealing
with hillside slopes of already established mature plantings, drip
systems are so much easier to
 install than trying to trench for pipes on steeper slopes, and work
around existing roots of plants/trees.

I also find it rather surprising that even a mediterranean plant
garden can actually look good on just once a week conventional
irrigation, it would not seem that the watering is going that much
deeper than with a longer running drip system, especially when you
factor in slopes and soil types that may limit the time that water
can be applied without running off.  I've met plenty of intelligent
gardeners in hot summer areas that swear by daily 10 minute watering
every day as being most useful to keep overall water use down, but
am not equally convinced that they are using less water than a drip
system would.

Does anyone actually have studies under controlled situations which
compare different scenarios of irrigation to be able to back up
their preferences?  I will admit that I clearly prefer drip for the
multitude of reasons I have cited, but also use conventional spray
systems, and in particular lower water application rate rotor stream
spray heads at wider spacings when I am trying to install a larger
system with the fewest heads.  I seldom use bubblers because I
seldom design gardens for flat conditions.  The few gardens where I
have utilized such systems always seem to be sandier soils that
don't hold onto to much water, and also windy sites, and I'll admit
that I haven't seemed to find the right combination of run times,
frequency and even time of day to give me the fool proof results
that I've gotten with the same types/locations of gardens with drip
installation.  I find myself having to bump up run times
considerably more in the
 hotter/drier/windier summer months to get the plants to do well,
and need to spend a lot more time pruning to keep heads completely
clear of obstructions.

My strong preference for drip systems is no doubt influenced by my
greater  familiarity with drip systems, the dense style of plantings
I generally prefer, and my annoyance with having to prune plants to
avoid poor coverage,  and possibly my own biases.  For design
projects that have less complex planting designs, and minimally
trained maintenance staff, there is no doubt that conventional
irrigation/non-drip systems are more obvious to see what is working
or not,, but are not necessarily easier to repair.  Either type of
system utilized is always more easily repaired and maintained if
there is a plan of the layout and enough notes on the run
times/schedules adjusted for seasonal differences to help the
homeowner understand the system.  Since so many installations never
get this level of design/maintenance support, the owners are often
left in the dark about how to make repairs or change run times most
appropriately to apply the least amount of
 water.  And lastly, effective irrigation is really only achieved by
observation of what works/doesn't work with a particular site.  I
will often add/subtract emitters over time as necessary to achieve
the growth of plants desired, but can only do this when I am able
to follow up quarterly on designs I've installed.  It is not
realistic to think that drip irrigation is a one time installation
that never needs to be tweaked; plants grow, coverage gets blocked,
sun/shade impacts water use, etc.

--- On Tue, 7/21/09, Joseph Seals <thegardenguru@yahoo.com> wrote:

From: Joseph Seals <thegardenguru@yahoo.com>
Subject: Re: Drip Irrigation
To: davidfeix@yahoo.com, "Plant Forum Mediterranean"
<medit-plants@ucdavis.edu>
Date: Tuesday, July 21, 2009, 7:32 AM

I never used the word "spray".

I have no doubt that spray (sprinkler, especially low-angle) heads
still have their place (limited) but my primary suggested
systems/heads are rotary and bubbler/flood.

The suggested timing for these systems are once a week watering for
the most water-thirsty Med. plants, once a month watering for
materials that need to be "refreshed" and no watering for most of
the plant material I suggest.  We asume we have an "established"
garden. I would certainly agree that if such "traditional" systems
were turned on as frequently as drip systems, then drip would win
hands-down for efficient water use.

I don't find a no-water-garden plant palette limited at all.  In
fact, my students are often overwhelmed by the long lists I hand
out.  I, too, like the Med. climate plants that don't look "dormant"
in the summer but, rather, give a spectacular show during our
hottest, driest months.  All quite possible.

Joe



Joe Seals
Horticultural Consultant
Pismo Beach, California
Home/Office: 805-295-6039

--- On Tue, 7/21/09, david feix <davidfeix@yahoo.com> wrote:


From: david feix <davidfeix@yahoo.com>
Subject: Drip Irrigation
To: "'mediterranean climate gardening e-mail forum for gardeners in
these climates throughout the world'" <medit-plants@ucdavis.edu>
Date: Tuesday, July 21, 2009, 5:53 AM






I would definitely agree with Joe that lower sustainable water use
for residential gardens is very much about "right plant for the
right place", but would still suggest that drip irrigation is
inherently more efficient in the application of such water without
the run-off, wind-drift and evaporation one can't help but get with
spray irrigation.  I would really like to see the support for the
statement that a well designed conventional spray system still uses
less water than drip, as quite frankly, I don't believe this
statement is universal, nor even the norm.  All of the gardens I
showed typically only get 15 to 30 minutes of irrigation via drip
emitters 2 to 3 times a week in the hottest weather, and in
combination with a good regularly reapplied mulch 2 to 3 inches
thick, most all the plants have been fine with this amount of
watering.  In a sandy soil garden in the western half of San
Francisco, built upon old dunes, I
 would typically only water for 10 minutes maximum with
microspray/drip, and again program for 2 to 3 times a week.
Admittedly, I garden and design gardens in the cooler maritime
mediterranean climate of the inner SF Bay Area, where it doesn't
get all that hot.  This allows me to use non-drought tolerant
plants in such situations as well, but I will typically link them
to their own independent valve which may get irrigation set daily
for just 5 to 10 minutes during the hottest weather.  The fact that
these valves are drip, with lower pressures and limited volume of
water does mean that they are using significantly less water than a
spray system would for the same plantings.  I have had the
opportunity to comparison test similar plantings side by side
between spray systems and drip in the same garden, and have nearly
always found that the drip irrigated plants establish faster, more
often look better under hotter weather conditions,
 and there are no problems with wind drift and water run-off, as
well as less weeds.  I wouldn't ever consider a spray system to be
a better design for narrow parkway strips between street and
sidewalk, it is inherently more wasteful of water and more subject
to wind drift.  I recently replaced such spray heads in a street
strip only 3.0 feet wide in nearby Alameda, with buried 1/4 in-line
drip tubing on 12 inch centers.  No more run-off, and  9 mpnths
later the plantings of Dymondia, Echeveria imbricata, Aeonium
nobile, Coleonema 'Sunset Gold', Cotyledon orbiculata, Lavandula
'Hidcote' and Sedum 'Angelina' have completely filled in and are
thriving with just twice a week 25 minute water cycles in a sandy
loam soil of dredged bay fill.  The lawn that was originally in
this strip had never looked green even with 3 times a week watering
from pop-up spray heads, and always had some water runoff into the
street.

As to how to
 counteract wildlife that have bothered drip irrigation, I have only
really had problems with the occasional squirrels, deer have not
been a problem in any of my gardens where they have free range, but
then you may be able to see from my preferred planting styles that
I don't typically leave much bare earth showing, nor exposed drip
lines.  I haven't had any problems with raccoons tearing up drip
irigation, either, although they have been terribly destructive of
some of my favorite plants(bromeliads), in the past, before I
elected to cover vulnerable plantings with bird netting, which
ended the problem.  With the squirrels, as I already mentioned, I
had to get more clever about mounting the hard plastic misters in
trees, so that it would take them hanging upside down to be able to
gnaw on the emitters.  Squirrels never have shown any interest in
the polyethylene supply tubing, nor have gophers or moles, in my
personal experience.

I
 would have to suggest that tubing and emitters would need to be
shallow buried and mulch covered in gardens where animals have been
a problem, but if even this doesn't work, then utilizing a drip
system that relies on microspray emitters within popup risers, and
hard plumbed with pvc pipe runs rather than flexible poly tubing
would still be a way around this, and possibly locating inground
drip emitters within protective wire baskets, as used to protect
root balls from rodents.  If you have to go to the trouble of
installing buried pvc pipe for irrigation, it may make more sense
to install spray heads that utilize lower volume stream sprays, but
also need to run for longer periods because they apply
substantially less water.  In garden situations where I have used
such a system, I still find it uses more water and plants grow more
slowly than with a comparable drip system, and much more care needs
to be taken to ensure that full irrigation
 coverage is not eventually blocked by plant growth.

The point about drip tubing heating up significantly in hot summer
areas makes the case for shallow burying the lines, and/or keeping
the garden well mulched so that the lines aren't exposed.  As a
general principle, I prefer the mechanics of the garden to remain
invisible anyway, and don't like to leave any drip tubing exposed
long term if at all possible.  In fact, for patio applications, I
typically will use 1/4 diameter copper tubing which can more easily
be painted to match the house for supply lines, and always prefer to
run drip tubing up through the drain holes of pots rather than over
the rims, if it is a new installation and not a retrofit.

In fact, I find myself returning to planting design themes first
explored in the drought years of the mid 1970's, when I was still a
landscape architecture student and all pumped up on designing
gardens with predominantly California
 native plants and no permanent supplemental irrigation. If push
came to shove, and we are faced with a similar drought situation as
places like Adelaide, Australia are going through, I am sure that I
could adapt my garden designs to be even more drought tolerant, but
we aren't faced with the same degree of limited water(yet!).   I
still found it more personally rewarding to combine a few plants
from outside California to add to the mix, yet would fit within the
same once a month supplemental irrigation schedule for a
mid-peninsula Menlo Park garden.  Over 30 years later, this garden
has still held up, and matured nicely.  These days I am more
inclined to include more colorful South African, Australian or
Mexican plants into the mix,(especially succulents), as I am after
using plants for the overall feeling and effects they bring to the
garden, rather than trying to imitate some natural landscape.  I
particularly enjoy matching a
 plant to the situation at hand, and harmonizing plants from similar
climates from around the world into one setting, as an attempt to
define a Bay Area look that fits our growing and climatic
conditions, yet doesn't need to read as "dormant" or "resting" at
the height of summer.  Perhaps this represents a "less evolved"
approach to landscape design in a time of limited water resources
and disappearing native plants due to habitat loss, and certainly
does not reflect the more politically correct approach of no summer
irrigation and only growing what is locally native, but I prefer my
contact with such environments out in the surrounding hills and
bayside, rather than my own garden.

The bottom line is one of making the best use of resources in a
sustainable manner that also pleases the end user, and if it also
pleases the designer, this is a bonus...  We will be faced with the
need to elimate wasteful irrigated lawns, even when they are
 allegedly drought tolerant ones such as the tall fescue blends.  I
won't design around a tall fescue lawn anymore unless the client
absolutley insists; instead, I've been pushing using no water
Kikuyu lawns,(so far no takers), artificial turf(2 installed so
far), and several lawns using non irrigated Carex species such as
Carex tumulicola(as in the photo of the garden with the recycled
concrete slab bench), and Carex pansa and Carex praegacilis lawns.
Even better in my view is ripping out the lawn all together and
replacing with shrubs/ground covers and succulents, or providing
decomposed granite as the blank space play area if one is needed
for young kids at home.

While I admire gardeners who actually design gardens with no
irrigation required at all, I find that the plantings possible in
such a regimen are usually a bit limiting.  Trying to achieve the
goal of less water use has pushed me toward much more garden
installation and
 planting in late fall and winter, and only confirms that such wet
season plantings almost always establish better with less water
required the following summer than a spring planted garden.  It
does become a problem however when dealing with clay soils and lots
of rain for days on end, and the danger of creating compacted soil
that hardens into concrete once dried out.  I also find myself
using a lot more desert climate plants that absolutely need no
summer irrigation to survive, and that includes many non-desert
plants such as Puyas, Dyckias, Hechtias that have the desert look,
yet still are colorful and vibrant and even bloom in the height of
summer.

--- On Mon, 7/20/09, Joseph Seals <thegardenguru@yahoo.com> wrote:


From: Joseph Seals <thegardenguru@yahoo.com>
Subject: RE: Watering in Summer
To: "'mediterranean climate gardening e-mail forum for gardeners in
these climates throughout the world'" <medit-plants@ucdavis.edu>,
mikemace@att.net
Date: Monday, July 20, 2009, 6:58 PM







Please don't take this as a personal afront Michael but you do make
me realize that a lot of people -- including, possibly, other
members of this forum -- have the idea that it's an either/or
situation:

Either we use drip or we waste/use a lot of water with traditional
irrigation systems.

That's not the case.

I think I've made it clear that the essential key to water
conservation is "right plant, right place".  In other words, using
plants ("Mediterranean") that don't need much supplemental water.

After that, it's a matter of using an "effective" watering system
that trains plants to have an extensive root system -- one that is
what we call "drought tolerant".

I know many people believe an old myth that says "plant roots find
water".  I'm sure plant roots don't.  Plant roots have no sensing
organs, no radar, no brain to lead them to wet soil.

Plant roots go where the water is -- where the gardener puts it.  If
we water deeply and infrequently and just beyond the drip line, we
train roots to go deep and wide.  And that's what gives them the
abililty to hold up when the rainless season comes along or when the
rainy seasons come along dry.

My experience -- and that of my students and clients and associates
-- is that using water wisely/effectively in the beginning leads to
unthirsty plants in the long run.  I've done the numbers and in the
long run, watering effectively with appropriate new versions of
traditonal irrigation uses less total water than with drip.


And thanks to David F. for giving me (and all others) the
opportunity to understand his irrigation approach and sytem better.

I should quit now otherwise I'll be accused of going from "tirade"
to "obsessed". ;-)

Joe



Joe Seals
Horticultural Consultant
Pismo Beach, California
Home/Office: 805-295-6039

--- On Tue, 7/21/09, Michael Mace <mikemace@att.net> wrote:


From: Michael Mace <mikemace@att.net>
Subject: RE: Watering in Summer
To: "'mediterranean climate gardening e-mail forum for gardeners in
these climates throughout the world'" <medit-plants@ucdavis.edu>
Date: Tuesday, July 21, 2009, 1:16 AM


I've been pretty happy with my drip system, but then I have an acre
of land
and couldn't afford to water it any other way.

Regarding the timing issue, if those drip tubes are above ground,
you need
to give them time to cool off after they've been in the sun.
Watering in
the afternoon will give your plants a nice little dose of scalding
water,
and because the tubes get soft when warm, you'll have more cases of
joints
blowing apart.

Mike
San Jose, CA (zone 9, min temp 20F)









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