As promised, here is my report on the new drip irrigation system we installed in our vegetable garden earlier this spring.
In the past, we have used soaker hoses on a sprinkler timer to water our raised beds. They worked fairly well but frequently became clogged from the build-up of minerals in our water. This meant we had to poke new holes in them every so often which was an annoying task. If you poked a little too hard, the hoses would spray all over the place, including on the pathways between our beds. And if you didn't poke enough holes, the plants wouldn't get enough water.
After doing a lot of research, as well as getting input from friends who had other types of systems, my husband Bill decided to completely replace our soaker hose set-up with a drip irrigation system. He chose the materials from Dripworks (www.dripworks.com). When you have the chance, I'd recommend visiting their website because there is a lot of helpful information on it including a blog, FAQs, design information and so on.
We were able to retain the same underground water lines to each row of raised beds that we've had for years, which was nice. One item that was new was a filter (left) that catches sediment before it gets into the watering system. It has the ability to be drained as needed and will keep the actual lines that water the beds from getting plugged up.
So here is the set-up (right): after water from our well goes through the filter and into the lines that go to each bed, it goes through a PVC riser (see photo below), through a new valve that controls the water flow, and into 3 or 4 runs of "T-tape" irrigation tubing. The T-tape looks like a flattened hose but actually has slits on the top of it through which water weeps. So when the watering system is running, the T-tape fills up to where it looks like a round tube. You can buy T-tape that has different spacings between the slits; ours has slits every 8".
Right now, we're watering our vegetable garden at 8 a.m. each morning for about 25 minutes. It has been working really well so far. One concern we have, though, is making sure any block plantings (like lettuce, Swiss chard, beets and basil) are getting enough water.
For example, my husband installed 3 runs of T-tape on our 3-foot-wide raised beds and 4 runs on the new 4-foot-wide beds. It seems to be working well for plants that are planted right next to a run of T-tape (i.e., corn, squash, tomatoes, beans, etc.) but when you plant a crop in a block, some plants will be right next to the T-tape and some will be a few inches away from it. Since the T-tape doesn't spray water in a wide area, that can be problematic. We're going to keep an eye on things and see how all of the plants do this season. But we might have to make a few modifications to accommodate block plantings so they get more water.
Overall, Bill is pleased with the set-up and felt the system went together pretty easily. And I have to say that I'm very lucky to have had watering systems for the veggie garden that are on timers! It would take me forever to drag around hoses to each bed, so it's a real time-saver and keeps the plants real healthy.