Drip irrigation parts for the first vegetable zone
Filter, regulator, line, and emitters for one raised-bed zone in hard Western water. A parts list, not a brand.
One vegetable bed on its own valve will teach you more than a catalog kit that tries to water the lawn, the penstemons, and the tomatoes together. Denver Water’s xeriscape guidance says turf and planted beds should be watered separately, and that drip or bubblers suit the beds.
This page is the hardware for that first bed zone: what has to be in the line, in what order, and what you can skip until the second year. The scheduling, the probe, and why there is no honest inch-per-week are on the drip irrigation page.
The order on the hose
Start at a hose bib you can winterize. Thread on, in this order: a timer if you want one, a filter, a pressure regulator, then the adapter to half-inch supply tubing.
The filter comes before the regulator so grit does not chew the regulator and so you can clean one screen instead of forty emitters. Western water is often hard and often full of fine grit. An unfiltered kit works for a month and then the tomatoes dry up while the timer still clicks.
Read the regulator’s range and the emitter’s range and make them match. Many drip emitters are happy around 15 to 25 psi and unhappy on full house pressure.
If you skip the regulator, you will find out on the first morning as mist, blown fittings, or a line that jumps the bed. Write the psi from the package on the takeoff. Do not guess from a neighbor’s kit.
What to lay on one 4-by-8 bed
Half-inch solid supply tubing from the bib to the bed, plus a length of drip line or individual emitters across the bed. Two runs down a 4-foot width, or one emitter near each plant you will actually keep watered, is enough for year one.
A soaker hose is the less even cousin. It is acceptable on a short, level bed and dishonest on a slope, where the bottom of the run becomes a bog. On a slope, put the supply at the high end and use emitters.
Quantity for one bed near the house:
| Part | A reasonable first quantity | Notes |
|---|---|---|
| Filter, screen or disk, hose-thread | 1 | Clean it when flow drops. That will happen. |
| Pressure regulator matched to the emitters | 1 | Put it after the filter. |
| Half-inch solid tubing | The distance from bib to bed, plus 5 feet | Extra is for a mistake and a gentle curve. |
| Drip line or emitters | 8 to 16 feet, or 8 to 12 emitters | Two lines on a 4-foot bed. |
| Barbed tees, a figure-eight end, or a flush cap | A handful | You will redo one joint. |
| Stakes or wire pins | Every few feet | Unpinned line walks when you weed. |
| Optional hose timer | 1 | Useful, and useless if the filter is clogged. |
A second bed on the same zone can tee off the supply if it wants the same schedule. A xeric shrub does not tee off the tomato zone.
That is the whole xeriscape point. The xeriscape page is the zoning. This page refuses to water both with one timer.
Installation that survives the first wind
Lay tubing on the surface. Do not bury thin drip line in clay. You will cut it with a trowel, and a clogged emitter underground is a mystery.
Mulch can cover the line lightly if you can still find the emitters. The mulch page is which mulch stays. Pin the supply so a gust does not drag the filter off the bib.
Flush the line before you cap the end, and again a few times a season.
Open the far end, run water until it runs clear, then close it. This is the maintenance people skip, and it is why year-two drip “does not work.”
Emitters go near the plant and move out as a shrub grows. A tree watered only at the trunk for five years falls over in the first real wind. For vegetables, keep the water in the root zone you can check with a screwdriver.
After a run, the blade should slide through moist soil to 6 or 8 inches for lettuce and deeper for a midsummer tomato. If it stops in dust at 3 inches, add time or add a cycle, especially on clay. Cycle and soak is on the clay page.
Winter, and the bill you avoid
Drain the zone before a hard freeze. Open the low points or blow the line. A line left full in October splits, and in May the bed is dry and the water bill is not.
Drip that is drained cannot do winter watering of trees. Use a hose and a basin on a mild day for that job. Do not leave the timer attached to a bib that will freeze.
If one emitter spits and the next is silent, pull the silent one and flush before you replace the whole line. A grain of sand is the usual culprit. Keep a few spare emitters in the same box as the timer battery.
A second bed that wants the same schedule can tee off this supply. A bed on a slope should not share a soaker with a level bed. Give the slope emitters, and give the level bed whatever you already trust.
Skip a 20-zone controller for a first vegetable bed. Skip mist heads sold as drip. Skip burying the filter where you will not unscrew it.
A simple mechanical timer, a filter you can see, and a regulator you can read are the whole first system. When that zone has run for a season without a mystery dry spot, add the next bed.
Rain barrels are not this system. Colorado’s residential allowance, in the state engineer’s explanation of section 37-96.5-103, is generally two barrels totaling no more than 110 gallons, from a roof, for outdoor use on the same property.
That fills containers. It does not carry a tomato bed through August. The drip page says the same thing. Other states write a different rule.
Checklist
- One valve for vegetables. Do not share it with the lawn or the penstemons.
- Filter, then regulator, then line. Match the regulator to the emitter.
- Surface tubing you can flush. Do not bury it in clay.
- Two runs or a handful of emitters on a 4-by-8 bed.
- Probe after you water. Add time until the root zone is wet.
- Drain it before a hard freeze.
- Price the short list above. A kit is fine if it contains those parts and not a pile of mismatched emitters.
Sources
- Denver Water, Xeriscape principles, separate turf zones and drip for beds.
- CSU Extension, Rainwater Collection in Colorado.
- Colorado Division of Water Resources, rain barrels.
- CSU Extension, Iron Chlorosis of Woody Plants, on what overwatering does in alkaline soil if the drip never rests.