We all take vacations or have to go away for a few days, who is going to water our bonsai? I mean the whole family is away, there is nobody home! Some people hire a house sitter, a friend or a neighboring kid to water their bonsai; the outcome can be great or disastrous depending on how reliable is the help.
My wife and I often take vacations from a few days to as long as 5 weeks, we need a reliable watering system for our bonsai. I experimented with several automatic sprinkler systems for the last 20 years or so, and found the one we have been using for about 10 years works well for us. When we set up this sprinkler system, our objective is to allow us to go away, the bonsai are watered and are alive when we come back. Not necessarily they receive the best of cares. For that, you need to stay home or board them in a professional nursery. I want to share how we do it, hopefully, readers will also share their experience and watering system benefitting others too.
Our system is quite simple, it relies on duplications and backups. We use two hose-end water timers to deliver water to one set of sprinklers. The logic is chances for two watering timers to fail during the period we are away are quite low, and that turned out to be true so far.
Each timer is attached to its own spigot. Water from both spigots are fed to a common pipeline which delivers water to the bonsai sprinklers. One timer runs in the morning, the other in the afternoon. Two watering cycles. Should one timer fail to work, the bonsai are watered at least once a day. Here is a schematic of the set up:
This is our physical set-up.
We use battery operated timers instead of electrical solenoid control valves, this is to make sure power failure does not mess up the main electronic control. The simpler the control, the less chance of mishaps. An orchid friend told a story of someone in his Society built a fancy greenhouse with computer controlled temperature and humidity; the computer failed one day and went into default heating mode. All his orchids were roasted upon his return.
It is important to use a reliable water timer. We liked our old Gilmore 8-cycle timers but they were no longer in production. We switched to the DIG 4-cycle timers, it is not as flexible as the old Gilmore in setting multiple cycle times, but they have been reliable so far. As a precaution, we also give a spare timer to our neighbor should we need to have him to replace if one were to fail, and this has not happened.
The outlet hose of each timer is connected to a check-valve to prevent back-flow when the other is operating. The two check valves are connected to a T-joint which feeds into a common underground pipe line to the sprinklers in the bonsai patch.
How Do You Know Your Bonsai Are Watered?
Security cameras! I position one close to the sprinkler. It detects motions when the sprinkler is on and the cloud server sends me an email alerting motions have been detected. When I hear a ping from my phone at say, 3 PM, a time set for one of the timers, I know the sprinkler is on. I can see the video in real time or review it later from the server. I also set cameras close to some of the more important bonsai trees so I can see how they are doing at any time by turning on the video and zooming in. Since my cameras are several years old and has only 720 dpi resolution, the video is fuzzy especially when water is splashing on the lens. Nevertheless, it is adequate for us to see water droplets coming out the sprinkler and our bonsai are watered.
These days security cameras come with 1080 dpi and 4K resolutions, wider field of view etc. Many competitive models are available for you to find one that suits your purpose. It is also time for me to update some of my security cameras.
Nothing is fail safe. It is how well you prepared for it. I replace the timers with new batteries, test the system several days before we go on vacation, adjust spacings between bonsai so it does not block water reaching the neighboring trees, that they receive enough water and there is no sign of distress during this test period. I also surround the taller bonsai with bricks to make sure wind or squirrels do not tip them over. Most of all, be prepared to accept dead bonsai should accident happened. If you accept that, the automatic sprinklers will set you free, allowing you to travel.