One of the challenges of summer kitchen gardening in the Pacific Northwest is the lack of significant rain from June to September. In New England, where I started gardening, I could count on regular rain all season long. Not here. My first northwest garden was small enough that I could reach most if it with a hose and watering wand once I admitted that it really wasn’t going to rain that week or the next or the next. My next garden was bigger and I soon realized that hand watering simply wasn’t going to work. I needed an irrigation system. It’s taken a while, but thanks to Scott and a series of experiments we finally have an irrigation setup that works almost better than those New England rains did.
Our first experiments with irrigation systems relied on soaker hoses, those flexible, black, porous hoses made from recycled rubber. Not only did they provide good irrigation, they were inexpensive and easy to install. After a few years, the tiny holes that let the water leak out did start to clog up a bit and after a few more years, they didn’t leak much at all, but soaker hoses were still available and not too expensive so we just replaced them. They were our irrigation choice for nearly two decades.
Several years ago, though, soaker hoses suddenly got harder to find at a reasonable price. At the same time we started thinking that it would be really nice to have an irrigation system that didn’t require quite so much dragging of water hoses to soaker hoses and coupling and uncoupling of hose fittings. A timer that shut off the water automatically would be nice too. And while we were making a wish list, irrigation hoses that lasted longer would be nice and certainly less wasteful. Fortunately for our growing wish list, we found DripWorks and, specifically, T-Tape irrigation. I think it will be our irrigation choice for the next two decades and more.
This page from the DripWorks website defines T-Tape and explains how it works: http://www.dripworks.com/category/ttape1. In addition to low cost and ease of installation, T-Tape pleased us because it operates with low water pressure and the water is still distributed evenly along each tape. And a length of T-Tape lasts up to seven years when covered with mulch. We also purchased a simple timer that turns off the water automatically. It is necessary to use a filter at the water source to remove sediment and other particles big enough to clog the T-Tape but it was easy to install the filter.
If you are interested in setting up an irrigation system, visit the DripWorks website, http://www.dripworks.com/, which not only lists their products but also provides very useful print material and videos on how to select and install their irrigation systems. And read this guide: http://cdn.dripworks.com/downloads/manuals/DripPlanningGuide.pdf. The company also offers phone consultations on irrigations plans. We drafted a design for our system and then talked with a DripWorks staff person who reviewed our plans and helped with our order.
In our plan, we divided our twenty-one five-by-eighteen foot garden beds into three zones of seven beds each. This photo shows nearly all of the three zones. We connected the seven beds in each zone with a supply line, buried just below ground level. At the head of each bed in a zone, there is a tee fitting coming off the supply line and an shut-off valve, and at the end of each of these three supply lines, there is a hose coupler where we attach the water hose. Now instead of dragging a hose to each of the twenty-one beds, we simply drag it to one of the three zones from the centrally located hose bib where we also installed a water filter, flow restrictor and a timer. And within each zone, we can use the shut-off valves at each bed to supply irrigation to the beds that need it and avoid watering beds that don’t.
While these supply lines and valves are permanent, we move the T-Tape itself from bed to bed depending on what we’re planting. Each T-Tape unit consists of a short supply line to which we’ve attached two, three or four lengths of T-Tape. The short supply lines attach to the tee fittings at the head of each bed. Our beds typically contain two, three or four rows of plants so we figured out how many units of each size we needed and assembled them. At the end of the growing season, we detach the T-Tape units from the supply valve at each bed, screw a cap to the supply valve to keep bugs and dirt from getting in, fold the T-Tape accordion fashion along the supply line and store it until the next year. From start to finish, it’s a great system.
This photo shows the tee fitting coming off the buried supply line, the shut-off valve, the supply line for the bed, and finally, lengths of T-Tape connected with fittings to the supply line. For this bed of bush dry beans, we spaced three T-Tapes eighteen inches apart along the supply line to the bed.
In this photo, tiny threads of leeks are starting to grow along the four lengths of T-Tape spaced a foot apart. The photo below shows melon plants I just set out along three lengths of T-Tape. I’ll lay strips of black plastic in the rows between the beds and set a cloche over this bed to provide the warmth it takes to ripen melons. And, of course, the T-Tape will provide the water.
There’s been one more unexpected benefit to using T-Tape. The lengths of T-Tape in each bed define the rows and, just as convenient, the emitters along the tape where the water drips out are spaced eight inches apart and work as a surprisingly handy ruler. I space some plants eight inches apart, others sixteen, and others at twenty-four or thirty-two inches. The T-Tape emitters have it laid out for me. That’s something New England rains, welcome as they were, could never do.