I am not sure what that might do to the water pressure if I take off the drain and add it there. The drain is threaded via a 1/2 in connection while the main line is 1 in. If I did that, the input line would go from a 1" down to a 1/2" and back to a 1" for the new valves. I Suspect the drain was installed to completely drain the manifold over winter. As I see it, there is no way to cut the elbow to extend a stretch of pipe to a new box, which is what I would like to do. I popped into an irrigation shop down in Denver and they concurred that a manifold rebuild was the right way to do it. Bummer for me and my back with all the digging to splice the current lines and reinstall a new manifold, but at least I get to learn something new with this little project. Thanks for the response.

I agree first see if your controller has additional capacity, the controller may say right on it how many stations it has otherwise look where the wires attach to see empty spaces on the termianal strip, if not you will need a new one which is reasonably cheap and easy. While your at it look at the field wiring to see if there are already spare conductors between the clock and the valve manifold; look at the terminal strip in the clock and see if there are any unused wires; this will likely make your addition of a zone that much easier. As for your actual install of the zone, around here at least, irrigation contractors are usually more than happy to come and "pull in" some poly pipe for reasonably small dollars. This is really the hard part and once done it is simply a matter of some easy plumbing and installing of heads and a valve. In my opinion, and not having benefit of seeing your specific site situation, I would consider this to be a simple homeowner project, provided you have some measure of mechanical aptitude and do some reading around the subject at some of the irrigation links provided in other posts.

lehua, Unfortunately the money situation is such that I'm stuck doing this on my own. What difference would the pressure and flow of water have on grouping plants ? I'm no irrigation specialist but my logic tells me that once you have grouped your plants and/or established a drip scenario which could cover certain plants, then you need to know whether the water supply will allow it without breakdown into more zones - or have I missed something obvious ;) ? What I'm after is just a comment on whether my grouping of plants (which by default I made into separate zones) could be reduced i.e. are plants from one or more of those zones compatible in their water cycles to be joined into a bigger group / zone if the water supply allows it ? I had a few postings in this forum before about my concern about which plants could be grouped but the answers implied that you could water anything if the supply was there. As far as I understand fruit trees, citrus trees like deep watering - eg once a week. Vegetables every day or once every two days and so on. Which plants would you definitely put on a separate zone just because their watering needs are not compatible with others (forgetting about water supply for a start) ?

Xoxosmom, I am not an expert, but I have been doing some research. The decision of sprinkler Vs Drip is actually made on the basis of what type of plants are planned in the strip. Veggies and like that need constant moisture do well with Drip. Large shrubs perhaps might benefit from sprinklers. Another consideration is, if your plants get completely drenched by sprinklers, it attracts slugs. If the plant planned has a trunk, then perhaps a sprinkler might be ok. Also, since you are starting a new garden, how about planting some draught tolerant natives that need no water once established? Things like ground covers, native bushes/grasses etc.? Just my 2c.