Irrigation Installation
The nursery section adjacent to the raised beds had existing rain and city water connections that we tied into. We expanded around the sides of the nursery to anticipate for future expansion as well as took two lines out to the raised bed. The bed was double plumbed for both city and rainwater.
The tiller attachment for the Toro-Dingo was used to trench the ground for the schedule 40 PVC pipe. Hose bib risers were attached in 8 locations between the bed and nursery extension. There were 4 main cut off locations for the nursery and the bed, 2 of them were open with ball valves so that the pipes could be drained. One main was right passed where the existing pipes are and the other was where the main lines connected to the larger section of the bed. As for the two drainage areas one was located outside the smaller "L" section of the bed and the other was at the lower end of the larger bed. Every 16 feet in the 7 smaller zones of the bed, elbows were placed to make risers for the drip system connected to city water, and one was placed in the rain-water section. The installation of the drip system is discussed in the last section of this page. |
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Laying The Stone & Prepping the Bed
The area where the bed is was treated with a herbicide spray. After the string on the T-posts was leveled and shaped for the size of the bed the Dingo was used to till the native soil. We then went through and hand trenched with a shovel to the depth needed to lay the stone so that the substrate would be 8" in depth along the rocks. That spec required us to dig 2" down on the back side against the fence and just about 1" on the front side due to the slope of the land. We used the string line from the T-posts to set the corners of the bed with the stone and laid the stone accordingly. We left the ends of each side of the bed open so that we could get equipment inside to re-till prior to laying substrate.
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Adding the Substrate, Mulch and Caliche
Once all the limestone had been laid, weed barrier was placed along the edges of the limestone so that the substrate would be held in place. The weed barrier did not cover the native soil. A tractor was used to transport the topsoil and organic matter to the bed, where it was spread out by hand with a tine-bow rake. The topsoil and organic matter was laid in a 3:1 ratio, respectively. The depth of the mix was 8" at the edges, mounding to 10" in the center to allow for proper drainage. A half inch layer of pine bark mulch was added on top of the substrate mix.
A caliche path was made 5 feet off the perimeter of the bed and down to the nursery shade structure. |
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Drip Irrigation Installation
As the limestone was being laid, the PVC was being added onto the lines we had done the month prior. The bed was double plumbed with city water and rainwater. At each zone a T joint was used to connect the pipes and an elbow was added on top of the T to the height of the substrate, where it was then connected to a 10-psi flow regulator, ball valve and drip tape connector as shown in the slideshow. A piece of drip tape was added from the connector off the ball valve to a T-connector which started the drip tape section. For each zone 6 T's and 2 elbows came off the drip line and were spaced approximately 2 feet apart. The drip line was capped at the end by bending the tape and sliding a piece over it.
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