I’ll be a part time resident at first. It might sit unoccupied for a week or two at a time. Inside the home will be a “living wall” of plants. They have timed grow lights and a scheduled drip watering system. My dilemma is, I don’t like leaving the water to the house turned on for extended periods of not being there. Disasters happen. Here’s my idea and I need somebody to offer their opinions of my automation solution. First, I put a Z-wave water valve shutoff actuator on the garage on the main water shutoff valve. Next, I skip installing the usual sprinkler timer on the 12v solenoid sprinkler valve that waters the plant wall. I wire it instead, directly to a 12v output 110v adapter and then plug that into a Z-wave smart plug. Then, using the Smarthings app and hub, I scheduled them to both open at once, one time weekly, stay open for 15 minutes for the plants to get watered, then both to shut off at once. My plants get watered weekly and my main water shutoff remains closed at all other times eliminating unattended water leak risk. Thoughts? Thanks!
I feel that this is completely do-able. Just remember that these systems run in the cloud, which is not always reliable. I would integrate some system to confirm that your water valves are closed. Not sure how to do that in ST. I do those things in webcore.
My main thought is that you just can’t trust a smartthings system to be reliable enough to maintain living conditions for either plants or animals.
That’s not just my opinion: the official smartthings product usage guidelines say the same thing:
https://www.smartthings.com/guidelines
- Data accuracy and consistency from SmartThings sensors, including those provided by SmartThings directly, resold by SmartThings, or supported by SmartThings, is not guaranteed. Therefore, you should not rely on that data for any use that impacts health, safety, security, property or financial interests. For example, because temperature readings may vary significantly from reading to reading on an individual device, between devices, or over time, those readings should not be used to control heating and cooling in environments where food spoilage, health risks, or damage to physical goods could occur. Alternately, presence data from SmartThings devices or mobile/Smartphones can vary in accuracy, and therefore should not be used to control access to secure locations without secondary authentication.
Better to just set up a local timer system. 
I thought about a Wyze cam trained on the main shutoff valve for visual confirmation . Maybe I should consider a Hubitat for its local control. No cloud needed.
I agree that would be more secure. But, that would require my water valve be left on full-time. Too risky for my comfort. If the cloud went offline for hours or even days, the plants might not like it or they might be a bit droopy after a few days without water, but they’d be OK. Along with a Wyze cam on the main shutoff valve for I think I’ll have one looking at the plant wall for occasional check-ins.
I meant put the water valve on a local timer, these are widely available. 
Your straightforward approach here is simple and will work if “all things” are operational as expected. Redundancy quickly becomes expensive and chaotic when you start planning for the “What-ifs?”