Too much hand watering

A local gardener erected this 20' x 40' greenhouse. Last summer, the owner spent one hour each evening and one more hour in the morning watering the plants in the greenhouse. Despite all her work, she wasn't even sure that the plants received enough water from the watering wand she used.

This year she did not wish to spend so much time watering and wanted to devote more time to caring for the plants. She also wanted to know for sure that the irrigation water will go down to the roots, so she asked that we supply and help install a drip irrigation system.

This greenhouse is an excellent example of how the irrigation of a greenhouse or home garden can be completely automated.

Black plastic wire ties hold the standpipe
to the wooden stake

Standpipes

We made up two standpipes out of schedule 40 PVC fittings, one for each circuit (or zone) See a Standpipe construction article here. The owner will use garden hose to supply water from a nearby faucet to each standpipe.

There was no convenient place to fasten the standpipes so we drove four-foot long wooden stakes in the ground and fastened the standpipes with large plastic wire ties top and bottom. The faucet assembly shown on the left included (from the top) a TM8 timer, an FLR4 filter, a PR2 pressure regulator and an FC16 adaptor.

An FB8 barbed elbow turned the corner at the ground and the T2 tubing formed the header across the end of the greenhouse. FB5 Tees were used to create the start of each row.

Thinwall dripline

T2100 tubing was installed in most of the rows. Holes will be punched in the tubing and D4 drippers installed at each plant.

On three rows, there are close-spaced plants such as beans, so it was decided to use thinwall dripline for those rows only, providing .6 gallons per hour every 12".

To install the thinwall dripline in each row, an FB5 barbed tee was installed in the header followed by a short length of T2 tubing and a FB17T adaptor to join the DL6 thinwall dripline. Click on the photo to the right to see the detail.

Thinwall Dripline goes to the left
and a flush end is to the right

Extra row across

The owner wanted one row of dripline across the end of the greenhouse to grow corn. We used an FB5 to tee into the last row of T2 tubing then we added a short piece of T2 tubing and an FB17T adaptor to join with DL6 thinwall dripline shown on the left side of the photo.

To the right of the tee, we added a short piece of T2 tubing and an OE7 end stop which forms a easy-to-open end to flush the line.

Outside of the greenhouse wall, there are ten half-barrels for flowers, so we punched holes in the T2 tubing closest to the wall and inserted 1/4" couplers (FB10) and a length of T3100 1/4" tubing that reached to the middle of each barrel. There the owner will add an SP2 Bubbler Head mounted on an 8" tall SP5 Sprayer Stake.

The Bubbler Head is adjustable and will provide up to 20 gallons per hour for each barrel.

The greenhouse will now be irrigated automatically each day and the owner can spend time tending her plants instead of watering by hand.

1/4" couplers were punched in and 1/4" tubing attached to feed a bubbler at each flower barrel