By code you should have your valves with anti-siphon above the height of your irrigation, or alternatively have a vacuum breaker before the valves. Depending on the layout and density of plantimgs, it may make as much sense to use continuous emitter line tubing at regular spacing acrosd the slope. I've used this approach with succulents on a much steeper slope, using 1/2" emitter line with emitters at 12" on center, laying out parallel lines at same elevation about 18" apart. Heavy mulch spread over all bare ground kept the weeds under control until the plants completely filled in in 6 months time. This system replaced an existing spray system which couldn't adequately soak the root zone without causing erosion and run-off. The water bill was halved, and pre-existing plants along with the new are thriving. I've also redesigned steep slope plantings with existing spray irrigation which was not switched out with new supplemental plantings. Again, thorough weed control utilized heavy mulching to minimize weeds. This other garden slope was much more heavily shaded by trees, so water use is still reasonable given it isn't drip. In any case, I'd recommend use of coarse fibrous redwood bark mulch to "stick" to the slope, and possibly clearing all weeds prior to applying mulch, and maybe applying a weed pre-emergent prior to mulching as well.

lkbum, Great looking steps and dock! It looks like you must be on a canal? I noticed they do that often in the South to increase access to lakes and or rivers. Our slope is longer but same idea. I agree with you about doing things with your hands. As far as opportunity cost I could hire out jobs and make more money than I would spend on labor but it provides me with satisfaction. With my profession I see so many good kids that live in situations where they really don't have a chance. Sometimes it's kinda overwhelming. Unfortunately, a parent transplant is not an approved proceedure!

I had a grassy slope at a previous Zone 6 home that was prime real estate for a lawnmower-accident-waiting-to-happen. I decided to convert it to ivy. Mine was probably a 3rd the size of yours. Starting at the top of the slope, I killed a 1' strip of grass along the top with Round-up and then 7 days later, after the Round-up had done its thing I planted about one dozen ivy plants in the strip (maybe 1' apart?). I mulched the strip heavily (to discourage weed germination) and was faithful in watering the dozen new plants. As the plants grew, the growing strands were pulled into the surrounding bare spaces. To encourage the strands to root along their length, they were "pinned" to the soil with hair pins. When the ivy approached the grass at the bottom of the cleared strip, I cleared another 1' strip below (so now there was a 2' strip cleared from the top of the slope and toward its base). The process continued until the area was complete. Ivy is very easy to root, so this is another reason to use it. You can grow many new plants for a nominal cost and these will help to speed your project along and be very kind to your budget.

Yes, they are quite viable plants but you will need to fence off the area from kids and dogs while the roots establish. (That goes for most anything, not just bare rooted plants.) Once the ivy takes hold it will withstand the occasional traffic, but not while establishing.