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dancingnancy55

Drip irrigation - how to know how much water?

dancingnancy55
16 years ago

I saw the recent thread about drip irrigation systems. I have just installed the Dripworks kits on all my roses (and daylilies and a side border garden, too). Right now, I'm running the irrigation system on a timer for 30 minutes 3 days a week, but I have no idea how to gauge how much water the roses really need. Any suggestions on how much / how long to run the water. All the roses seem to be happy, so I've left it alone.

Nancy in Lenoir, NC

Comments (21)

  • anntn6b
    16 years ago

    Which size drip emitters did Dripworks sell? 1/2 gph, 1 gph or 2gph...that makes a difference (duh).
    Is your soil clay (retains moisture) or sand (just says howdy as the water runs through)?

    Roseman missed the commonsense answer, though. Your roses can tell you if they are getting enough water. Deadhead them by snapping the old blooms off at the abscission layer. If they snap easily; they've got enough water. If they don't snap with one flick of the fingers, they need more.

    (And there are more things to take into consideration if your water is coming from a well. You can't just run a well continuously, unless your well is truly wonderful; ours isn't)

  • michaelg
    16 years ago

    If you don't have specs for your emitters, catch water in a basin and measure it.

    1" per week is the normal recommendation for moderate weather, up to 2" for desert climates in summer. In the Piedmont, you probably need a bit more than an inch per week during hot summer weather, but a bit less than an inch in fall or spring.

    1" is roughly 2 gallons on a 2 x 2' area or 4 gallons on a 3 x 3' area. In sandy soil you might apply as little as 1 gallon at a time every other day. Applying 3 or 4 gallons at a time would just be wasting water downward. In medium to heavy soil or organic soil you could apply more at a time but less frequently.

    I figure if stems of most roses start new growth buds within two weeks of deadheading, the water is OK. So you could try applying the recommended amount and observe how the roses grow.

  • michaelg
    16 years ago

    PS, "area" refers roughly to the width of the plant canopy.

  • dancingnancy55
    Original Author
    16 years ago

    Thanks for the feedback. I am in the rock-hard red clay of the North Carolina foothills, but my soil where the roses are is pretty well amended, so it doesn't turn into brick like the rest of my yard. I didn't know that shrubblers came in "volumes" - I'll have to see if I can find my invoice and check it out, 'cause I don't know. When I deadhead the roses, they do snap off pretty cleanly, so if that shows they're getting enough water, I guess I'm doing okay.

  • michaelg
    16 years ago

    It doesn't show whether or not you are wasting water, though. You need to know how much you are applying,

  • michelle_co
    16 years ago

    The shrubblers give a varying amount of water depending on how they are adjusted. According to the chart at Dripworks, it should vary from about 6 gph to 13 gph. Just stick one in a bucket when you are watering and see how much water collects. At least you will know what your starting point is... Set on their maximum, you might only need to run your watering system for 15 minutes to deliver 5 gallons of water per plant.

    My well pump is too wimpy to use many of those on a drip system. I have to use lower output drippers, but then run them longer to compensate.

    Cheers,
    Michelle

    Here is a link that might be useful: shrubbler info

  • pagan
    16 years ago

    along with the deadheading trick, I noticed that Louis XVI gets droopy looking when he wants water - come a good rain (or watering) and he perks right up!)

  • berndoodle
    16 years ago

    Actually, many plants will droop in high temperatures, whether they are well-watered or not. Just to keep us on our toes, they will also droop when they need water. Nothing replaces getting down on your hands and knees with a trowel or a shovel, digging 6 inches down in the soil and touching it with your fingers to see if it is damp. If it's always damp, then you need to dig a little deeper to make sure the rose isn't standing in water - - if you didn't plan drainage into your garden automatically.

  • Jeannie Cochell
    16 years ago

    We've been telling people for years to use a sharp stick, poked into the ground at the leafline within 1 hour of watering, and where it stops is either rock or dry soil. In our area we recommend that stick sink to a depth of 14-16inches. More if a climber, less if new plantings or minis. Think of an oil dipstick. Works for us in the arid southwest.

  • lagomorphmom
    16 years ago

    Good idea, moroseaz!

    One thing I can tell you NOT TO DO, is use the battery powered timers on the drip, either turn it on manually or do it right with an electronic anti-siphon valve and electric timer (it has battery backup).

    We tried three different brands of battery powered valves in the last year (RainBird, DIG, and I forget the other one) and most leaked and shorted out one brand would go through a battery a week (that shouldn't be). Getting the timer into the house or garage solves the whole leakage issue.

    The shrubblers look nice, for a whole rose bush do you use two half shrubblers to wet both sides???

  • Jeannie Cochell
    16 years ago

    We're forever having problems with leaking valves. The desert sun does no favors to any device, especially if there's any rubber or plastic involved. The trick was to plant something underneath the valves that could take the leak, not take over the valves and wouldn't move me to tears when it had to be torn out. Oregano is real good for this purpose, lol.

    When I set out emitters, I'm looking at coverage area, not individual bushes in the bed. Spray emitters get staggered enough to provide water out and beyond the leafline. Depending on the spray pattern, they may be set every 18inches. Depends on water pressure, too. Some minis don't have emitters on them as they benefit from a puddling effect and run-off. When water is as precious a commodity as it is in this area, you take advantage of every drop.

  • jont1
    16 years ago

    I generally have about 20-25 roses on each drip irrigation system.
    I usually water each system for about 2 hours per week and this seems to be a good amount for my area. I have never really measured it, I just know my roses look good and it seems to be working.
    I have very good loamy soil to deal with that drains well yet holds the water well making it available to the bushes.
    I mulch very heavily as well which helps maintain an even temperature for the roots and I think conserves water by preventing too much evaporation.
    John

  • michaelg
    16 years ago

    I just don't understand why anyone would water without figuring out how much they are watering.

    Well, I got this medicine for the baby, I didn't read the label, but I just give her some, as much as feels right to me, every now and again, and she's OK so far.
    :)

  • berndoodle
    16 years ago

    Actually, Michael, with experience, knowledge of soils type and a pressure regulator, we have a very good idea. We use pressure regulated emitters, too. So a one gallon per hour emitter should be just that.

  • dancingnancy55
    Original Author
    16 years ago

    Alright, I measured the output of the last shrubbler on the line by putting it into a bucket - and it took 8 minutes to collect 1 gallon of water. So, my 30 minutes of watering should be providing about 3.5 gallons per bush. But, then the next question is, is this enough? Too much? Again, the roses are looking pretty healthy.

  • michaelg
    16 years ago

    You are applying 10 gallons a week, then, and probably more than that back up the line. That's about 2-1/2 inches if a 3' wide area is involved or 5 inches on a 2' wide area-- seems like twice as much as is needed in midsummer, or more than twice if the plants are small.

  • berndoodle
    16 years ago

    What kind of soils do you have and how large are your roses? Even my enormous climbers are fine being watered twice a week for 20 minutes in sandy loam. We water for the plants that need the least water and use multiple emitters for the plants that need more water. So if most of your garden would be fine with 15 minutes 3 days a week, you can put two emitters on a big climber you want to have more water (tho I find climbers have massive root systems and are fine with the regular schedule, so that's a bad example).

    Newly planted plants need to be watered three or four times a week with less water until they are established. You can literally see them transform when they are ready to switch down to a regular schedule.

    One thing you cannot do with low flow irrigation is give your roses a good deep soaking before fertilizing them in the summer.

    Also- you really do need to check that you aren't drowning individual plants or producing runoff once you settle on a schedule. Three times a week is a lot of watering. Tests have shown that people are far worse at gauging whether their plants need water than scientific measurements based on evapotranspiration rates and season, even without soil moisture tests. What I'm saying is that it's easy and very normal to overwater.

  • michelle_co
    16 years ago

    I run the drip every other day. Last year I watered daily (half the duration that I water this season) as I had more young plants, and noticed that my established plants looked better and bloomed heavier. Prior to that I had been watering once a week.

    I also use a pressure regulator and pressure compensating emitters for most everything - though there are shrubblers on the golden arborvitae trees. It was cool to find 1/4 gph drippers on the dripworks site - those are going to be nice for my xeric plants.

    Cheers,
    Michelle

  • dancingnancy55
    Original Author
    16 years ago

    I have 4 mature bushes (Cherry Parfait, Queen Elizabeth, a Don Juan climber that is HUGE on a trellis, and Tropicana), 14 HT's and Floribundas that I put in bare-root this March, and 9 well established ground cover roses (Electric Blanket). I was concerned about the new roses drying out while their roots are getting established. The plants are all in a raised bed/terrace, and I'm not having any runoff. But, my water bills are a tad high....
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  • scarleta
    16 years ago

    What a lovely pictures , nice garden,whatever you are doing seems to be a fine job.I often question water quantity also, but we also get lots of rain at times, so I tend to give them 5 mins of water daily and stop it alltogether when it rains and from time to time give them little extra when they look a bit dry.It seems to be working and I never actually measured the water coming out of irrigation system.It all depends on so many factors like type of soil, type of plant, how crowded is the planted area , any cometition from near by trees.Also as said above the water cost etc.So I think as everyone said just get the feel for it.