\u2022 They can reduce water\nconsumption by 50%. <\/strong><\/p>\n\n\n\n \u2022 They can increase\nyields because plants always have water easily available. <\/strong><\/p>\n\n\n\n \u2022 Can work with low\nwater pressure. <\/strong><\/p>\n\n\n\n \u2022 There is less disease\nbecause foliage doesn\u2019t get wet. <\/strong><\/p>\n\n\n\n \u2022 Weed growth is less\nbecause most of the soil surface remains dry, only the part around the plants\ngets wet. <\/strong><\/p>\n\n\n\n \u2022 They reduce the amount\nof work needed, all you do is turn them on and off. You can even put the system\non a timer to do this automatically, reducing the work of irrigation to almost\nnothing. <\/strong><\/p>\n\n\n\n \u2022 They are the most\npractical way to water container plants. <\/strong><\/p>\n\n\n\n Disadvantages<\/strong><\/p>\n\n\n\n \u2022 These systems tend to\nbe quite expensive, as you need a lot of parts and pipes to cover a large\ngarden. They are also quite complex and time consuming to lay out. <\/p>\n\n\n\n \u2022 They tend to be\ninflexible in that they aren\u2019t easily moved once set up and are hard to work\naround. They are most useful for perennial plantings such as trees. <\/p>\n\n\n\n \u2022 They are not totally\nmaintenance free, the emitters can get clogged and tubing can be damaged by\ncareless used tools, rodents and sunlight (it\u2019s commonly covered with mulch to\nprotect it from sunlight). <\/p>\n\n\n\n \u2022 They encourage you to rely on technology. You just set the timer, or turn on a tap and go indoors, rather than getting out in the garden where you will notice problems as they occur. <\/p>\n\n\n\n If not monitored carefully automated systems can waste water (and\neven damage plants) by applying more water than is necessary. <\/p>\n\n\n\n \u2022 They are made from\nplastic and eventually become garbage. <\/strong><\/p>\n\n\n\n These systems are\nundoubtedly the way of the future in areas where water is scarce and\/or\nexpensive. If you are interested in setting up a fully automated drip system I\nsuggest you examine the books and commercial literature. Also look at the\nvarious systems in hardware stores, garden centers and more specialist stores.<\/p>\n\n\n\n Most drip fittings are\ndesigned for watering single plants and aren\u2019t well suited to a vegetable\ngarden, where you often want to soak the entire bed. Also most drip systems are\ndesigned for permanent installation, whereas with vegetables you need a greater\ndegree of flexibility. You change crops frequently and need to be able to\ncultivate the soil without having plastic pipe in the way. In-line drip emitter\ntubing solves these problems though (see below).<\/p>\n\n\n\n Drip system components<\/strong><\/p>\n\n\n\n Specialist\nirrigation shops are usually more expensive than do-it-yourself stores because\nthey sell higher quality components to professional contractors. This is more\ndurable than homeowner grade stuff and should last longer<\/p>\n\n\n\n Filter<\/strong><\/p>\n\n\n\n A good\nfilter is essential when using a drip system because the drippers have a very small aperture and\nif they get clogged with grit or debris they become useless (most are very hard\nto clean). Use a good, easily cleaned Y filter with a 150 mesh screen for clean\nmunicipal water. Dirtier well water (or pond water containing algae) may\nrequire a higher mesh filter<\/p>\n\n\n\n Backflow preventer<\/strong><\/p>\n\n\n\n This is a one way valve that\nonly allows water to travel in one direction. It is necessary (even legally\nrequired) when connecting to a potable water source, to prevent dirty water\nflowing backwards and contaminating the water supply. Anti-siphon control\nvalves don\u2019t work as well, nor does a vacuum breaker attached to the hose<\/p>\n\n\n\n Pressure regulator<\/strong><\/p>\n\n\n\n This\nreduces the house water pressure down to 15-30 psi (higher pressure can cause\ndrip fittings to malfunction). Cheap regulators are fixed, more expensive ones\nare adjustable.<\/p>\n\n\n\n Supply lines<\/strong><\/p>\n\n\n\n The supply lines that carry\nthe water to different parts of the garden are usually either rigid PVC laid\nunderground (best) or flexible polyethylene. The latter has the advantage that\nit doesn\u2019t have to be buried. In cold climates you usually drain the system for\nthe winter to prevent damage.<\/p>\n\n\n\n PVC is not a very\nenvironmentally friendly material and it would be nice to avoid it. I used it\nfor my garden because it was cheap, but it felt a bit strange dripping all that\nglue on to my lovely organic soil.<\/p>\n\n\n\n Length of pipe<\/strong><\/p>\n\n\n\n This is relevant because\nwater pressure drops with distance. For example 200 feet of \u00bd\u201d pipe can supply\n240 GPH, but if you double the length of the pipe to 400 feet, the output drops\nto 160 gph. Normally the maximum length for \u00bd inch pipe should be 200 feet. If\nyou need to go further than this you should use larger \u00be or 1 inch pipe to get\nto the center of the garden and then branch off from this with \u00bd\u201d pipe.<\/p>\n\n\n\n Drippers<\/strong><\/p>\n\n\n\n These are used for watering\nindividual plants. They plug directly into the \u00bd\u201d supply lines and can be\nspaced anywhere on the line. They are quite flexible in that you can add extra\ndrippers as plants get bigger and need more water, or take them out and plug\nthe holes if you want less. Flag drippers are good if the water isn\u2019t very\nclean as they can be taken apart and cleaned if they get clogged. On sloping\nground you may need pressure compensating emitters to get an even flow\n(otherwise low spots may get more water than high ones).<\/p>\n\n\n\n In-line drip emitter tubing<\/strong><\/p>\n\n\n\n These use the same black PVC\npipe as drip irrigation, but have emitters pre-installed in them every 12\u02dd or\nso. These work in much the same way as a soaker hose, but are more durable (and\nbetter in my opinion).<\/p>\n\n\n\n Drip emitter line is most\noften used for closely spaced small plants such as vegetables and groundcovers,\nbut short lengths can be attached to \u00bd inch pipe to water almost anything. I\nuse this combination for most of my garden. There is also \u00bd\u201d drip emitter\ntubing for greater flow.<\/p>\n\n\n\n Soil staples <\/strong><\/p>\n\n\n\n These are used to pin the\nflexible hose down and keep it from moving around. You can buy these, but I\nmake them myself from scrap wire (bend it around a \u00be pipe to get a nice even\ncurve).<\/p>\n\n\n\n Tools and accessories<\/strong><\/p>\n\n\n\n You\nwill need a hole punch for attaching drippers and a knife or secateurs for\ncutting the pipe. A fishing tackle box is great for keeping all of your small\nparts together and organized.<\/p>\n\n\n\n Irrigation controller<\/strong><\/p>\n\n\n\n This is\nused to turn the water on and off at pre-determined times. This saves work and\nensures the plants get the water they need, when they need it. It connects to\nthe control valves via low voltage wires. Some types have a battery backup so\nyou don\u2019t lose programming information if the power goes off.<\/p>\n\n\n\n Control valves<\/strong><\/p>\n\n\n\n Full automation requires a\ncontrol valve for each watering zone. These are usually combined in a manifold\nthat is placed near the water source and timer (usually in a box below ground).\nYou can also have manual controls for any circuits you only use occasionally.<\/p>\n\n\n\n An extra control valve is\nusually added to the manifold to turn the water supply on and off at the same\ntime as the chosen circuits. This ensures that water won\u2019t be wasted if there\nare leaks anywhere in the system, or if a control valve get stuck open.<\/p>\n\n\n\n The valves run on 24 volts\nand are connected to the controller or timer with 18 gauge wire. The whole\nthing is very simple to put together and well within the capabilities on any\nreasonably competent individual (I\u2019m electrically challenged but managed it\nwithout any problems).<\/p>\n\n\n\n Planning a drip system<\/strong><\/p>\n\n\n\n How much water is required.<\/strong><\/p>\n\n\n\n The first thing you need to\nknow when planning your irrigation system, is how much water is required to\nwater each bed. A general rule of thumb for watering vegetables says to give\nthe plants an inch of water per week. Of course this varies according to the\nweather and soil type; a very light soil might require as much as 2\u201d. It takes\n0.6 of a gallon to cover a square foot one with one inch of water, which means\nthat a hundred square foot bed would require 60 gallons of water per week. <\/p>\n\n\n\n When to water<\/strong><\/p>\n\n\n\n It wouldn\u2019t be a good idea\nto give your garden beds the full weeks supply of water at one time (much would\nprobably be wasted and by the end of the week it would be very dry). It is much\nbetter to spread this out through the week. Some people irrigate every day, but\nI prefer to water every other day (or even every third day). To supply 60\ngallons per week, would mean giving the bed just over 17 gallons every two\ndays. <\/p>\n\n\n\n Number of lines<\/strong><\/p>\n\n\n\n The number of drip emitter\nlines required for each bed, will depend upon your soil, but generally a 48\u201d\nwide bed would usually have three lines. One down the center and the two others\n8\u201d in from the sides of the bed (16\u201d apart). If a 48\u201d wide bed was 100 square\nfeet in area, it would be 25 feet long and would require 75 feet of tubing. If\nthere is a dripper spaced every foot along the bed, this would mean 23 drippers\nper length or 69 altogether (starting and ending a foot from the ends of the\nbed). If the drippers put out \u00bd GPH that would be 34 gallons per hour in total.\nTo get 17 GPH you would have to run the irrigation for a half hour. <\/p>\n\n\n\n Total garden needs<\/strong><\/p>\n\n\n\n Of course to get your total\nwater requirements, you need to add up the total number of square feet of beds.\nIf you had six 100 square foot beds multiplied by 60 gallons per week, you\nwould need 360 gallons of water per week, or 102 gallons every other day\n(assuming all of my math is correct). Whether you can supply this all at once\ndepends upon the flow rate of your water supply.<\/p>\n\n\n\n Flow<\/strong><\/p>\n\n\n\n The flow rate (volume of\nwater) a pipe can deliver, depends upon its size, length and water pressure.\nThe simple way to determine the flow rate from your tap is to time how many\nseconds it takes to fill a 1 gallon bucket and then divide that number into\n3600 seconds (an hour). This will give you the number of gallons available in\nan hour, or GPH. The maximum flow rate for an irrigation line is generally\nconsidered to be 75 percent of this. It\u2019s not a good idea to use a line to its\nabsolute capacity right from the start, as you may want to add more drip line\nat a later date. <\/p>\n\n\n\n If your flow rate isn\u2019t\nsufficient to supply 102 GPH this isn\u2019t necessarily a problem. You can simply\nwater parts of the garden at different times, or on different days. If we are\nwatering on alternate days anyway, we can do half one day and half the next.\nHowever this does mean the garden would have to be divided into more than one\nzone.<\/p>\n\n\n\n If you don\u2019t have a timer\nand control valves and are watering manually, you should have a timer which\nshuts off the water after a predetermined time. If you don\u2019t you may forget and\nleave it on far longer than needed (you can waste a lot of water this way).<\/p>\n\n\n\n It is very useful\n(essential even) to have a shutoff for each bed, so you can shut off beds that\ndon\u2019t need watering and don\u2019t have to water everything equally. This enables\nyou to better tailor the watering to match the requirements of the plants, as\nwell as save water.<\/p>\n\n\n\n Irri<\/strong>gation controller<\/strong><\/p>\n\n\n\n This turns the control valves\non and off at the preset times and allows you to forget about watering for long\nperiods of time.<\/p>\n\n\n\n Save water<\/strong><\/p>\n\n\n\n Drip irrigation is meant to\nsave water, but when you water automatically this doesn\u2019t always work out that\nway. It can be quite wasteful if you end up watering half empty beds, or after\nit has rained. To avoid this you need to keep a close eye on what is happening.\nYou also need to put a manual shutoff on each bed, so you can cut water to it\nat any time. You can also get a rain sensor, which shuts off the irrigation\nafter enough rain falls.<\/p>\n\n\n\n Installing a drip system<\/strong> <\/strong><\/p>\n\n\n\n Trenching<\/strong><\/p>\n\n\n\n Pipes for drip systems don\u2019t\nhave to be buried in trenches; they can run along the surface under mulch.\nThese should be anchoring firmly though, so they don\u2019t move around as water\npressure changes, or get tripped over.<\/p>\n\n\n\n Even though it\u2019s not\nessential, I prefer to bury the main supply lines underground, where they are\nless likely to get damaged. Run these to the main areas of the garden and put\nin risers as necessary. The main water pipe are usually buried 18\u201d deep, with\nbranch lines only 12\u201d deep.<\/p>\n\n\n\n If you decide to bury your\npipes then digging trenches should be an early priority. It\u2019s a lot easier to\nbuild a path over a water line than it is to run a water line under a path. As\nI\u2019ve mentioned before, any time you start digging you should be aware of the\npossibility of hitting buried water, gas or electric lines. Also try not to\ndisturb the roots of important trees.<\/p>\n\n\n\n If you run the pipes along\nthe edge of the paths, you will know where they are, and it will be easier to\nget to them if necessary. On a hillside you should run a line straight uphill,\nand tee off of it with lines across the contour (if you don\u2019t refill these\ncompletely they can even do double duty as swales).<\/p>\n\n\n\n If you are hand digging a\ntrench in hard dry soil, don\u2019t waste your time chipping away at it. Just dig\ndown a couple of inches along its entire length and fill the depression with\nwater. When this soaks in it will make watering much easier. Dig out the moist\nsoil and repeat the process as often as necessary (better yet do it in winter\nwhen the soil is moist).<\/p>\n\n\n\n It is important to make an\naccurate plan of where all of your buried water lines are located. This will\nsimplify your life at a later date, or that of the next occupant of your\ngarden.<\/p>\n\n\n\n Don\u2019t refill any trenches\nuntil you have tested the system for leaks, otherwise it will be a nightmare to\nfind any leaks. When refilling you should put all of the soil back in, even if\nit means leaving the trench as a slight hump. It will soon settle down to flat\nwhen the soil consolidates.<\/p>\n\n\n\n Assembly<\/strong><\/p>\n\n\n\n I like to lay out all of the\npipe and then glue it together (I don\u2019t cut the last piece in each run, until I\nhave glued everything else together, so I don\u2019t make it too short. Incidentally\nyou should never leave your glue can on unstable soil with the lid loose. I\nguarantee you will knock it over.<\/p>\n\n\n\n Assemble the backflow\npreventer, control valve, filter, and pressure regulator and any other control\nvalves (make sure you install everything so the water flows in the right\ndirection). Use teflon tape on any threads. The supply pipe then goes into\nthis. <\/p>\n\n\n\n Unroll flexible polyethylene\npipe carefully, don\u2019t just pull it from the inside of the coil or it will never\ngo flat. If it is very stiff you can leave it in the sun for a while to soften\nup. Soil staples will be a big help in holding it in place.<\/p>\n\n\n\n In very cold climates you\nneed to be able to empty the system so that it doesn\u2019t get damaged by freezing.\nThe easiest way to do this is to have all of the pipes sloping downhill, so\nthey can drain by gravity. You then just need screw off openings at the lowest\nand highest points. If you can\u2019t use gravity, you will have to blow out the\npipes with a compressor, which is more work.<\/p>\n\n\n\n When all of the system is\nfully assembled, you must flush out the pipes before closing the ends. This is\nvery important, as if you leave any debris in the tubing, the only way it can\nget out is through the drippers and it will clog them. Never install the drippers\nuntil everything has been flushed thoroughly.<\/p>\n\n\n\n Using a drip\nsystem<\/strong><\/p>\n\n\n\n A well functioning automated\ndrip system does its job without your attention and tends to become almost\ninvisible. However its big advantage (it doesn\u2019t need your input) is also its biggest\ndisadvantage, in that you can become less involved with watering the garden and\nso pay less attention to it. This can lead to you overlooking problems that\nneed your attention.<\/p>\n\n\n\n When you first get your\nsystem going you must watch it carefully to make sure it is functioning\nproperly. Watch for leaks whenever it is turned on (this isn\u2019t easy if it is\ncovered with mulch, so put this on later). Watch for wilted plants, which\nindicate water isn\u2019t getting through to them. Also make sure it isn\u2019t putting out\ntoo much water – wilted plants could be a sign of root rot from overly wet\nsoil.<\/p>\n\n\n\n You will have to spend a\nlittle time learning to program your timer, but you need to become familiar\nwith it. The system will work better if you can easily make any adjustments as\nneeded. <\/p>\n\n\n\n The system will need some\nannual maintenance to keep it working well. If there is any possibility of\nfreezing over the winter, you must drain the whole system in fall. In spring\nyou should check the entire system, clean the filter and flush the supply lines\nbefore starting it up. Over the winter pipes can get broken or clogged,\ndrippers can come loose and delicate parts like micro-sprinklers may cease to\nfunction properly.<\/p>\n","protected":false},"excerpt":{"rendered":"![\"\"](\"https:\/\/greenmanpublishing.com\/wp-content\/uploads\/2020\/04\/drip-irrigation.jpg\")
<\/figure>\n\n\n\n![\"\"](\"https:\/\/greenmanpublishing.com\/wp-content\/uploads\/2019\/09\/Drip-1024x678.jpg\")
![\"\"](\"https:\/\/greenmanpublishing.com\/wp-content\/uploads\/2020\/04\/drip-irrigation-3-768x1024.jpg\")
<\/figure>\n\n\n\n