Back Yard, part 2 - 2007

I specifically took this picture midday, to show the sun and shade pattern. First, the dirt in the foreground is supposed to be there: there is supposed to be a stone path there, not yet installed. The lawn successfully starts along the line between the scalloped bricks on the left and the regular bricks under the redwood tree at the right.

Note the pattern of sun and shade: for the most part, in the shady areas, the lawn is green. In the sunny areas, the lawn is brown. Indeed, this is part of the problem: the sunny and shady areas really ought to have their own separate sprinkler circuits, and they do not.

Having just now (on the date this was written: 5 July 2007) checked, there is an equally big problem: the brown areas correspond very well to areas not covered by the K-Rain rotary heads. As in the case of the front yard, the coverage of these Dial-A-Nozzle heads is uneven at best.

Finally, there is supposed to be head-to-head coverage:

It is close, yet because this is a rectangle and not a square, it is not fully head-to-head.

By the way, “head-to-head” is irrigation jargon for each sprinkler head spreading water all the way to the next head. It is more or less stating that all the turf should be covered by a minimum of two sprinkler heads at any point, for proper watering. On my drawing, head-to-head is indicated by the number 2. The other numbers indicate the number of sprinkler heads covering that particular point of turf in an ideal system where each sprinkler head has 100% uniformly even water distribution, which never ever happens in the real world—not even close!—even with the best commercial-grade heads. The areas covered by only one head (marked 1 in the drawing) are the theoretically under-watered parts, which would be expected to be brown. The higher numbers are theoretically over-watered, yet this is typically not a problem in the real world.

In theory, there ought to be a pair of heads along each of the long sides, in the middle. Yet, since the pipe runs down the center of the lawn and it would be a pain to re-dig and add a center lateral each direction, i am dealing with it. Notice that the brown spots in the photo do not correspond very well to the theoretical 4 head coverage that should be taking place: instead of the 4 small slivers of inadequate coverage, there are wide areas which should have at least head-to-head coverage. My sense is that with decent heads, the unevenness would be much less noticeable.

Here is another view of the avocado trees and bird of paradise in the south end of the backyard, showing more of the tree canopy. (This picture was taken from beneath the redwood tree canopy, visible at the top of the image.) Sharp eyes will see the black compost bin at the left, and the wood pile on the right. These trees are plenty mature enough to not be counting on an irrigation system for their survival. While we have not wanted to test them by disabling their drippers, i like to think that the drippers keep them happier and more productive than ground water alone, especially in the drought years.

Walking to the wood pile and turning around to look northeast, one sees this view of the rose garden, sandwiched between the east edge of the backyard lawn and the garage. Also visible are a very happy crape myrtle, some succulents, a rosemary bush, and a hybridized mandarin lime tree, whose suckers prefer to generate lemons. Just outside of view on the right edge is the mature and productive Meyer lemon tree.

Yes, there are some brown weeds in this bed. The wood chips and the drip irrigation keep the weeds way, way down vs. typical sprinkling, yet several years of rain and no weeding will still generate plenty of weeds, esp. since there are plenty of grass seeds in this bed from careless gardeners in years past and the former sprinklers keeping the grasses in this area growing all too well. These weeds were whacked with Roundup®, hence the brownness.

Back yard, part 3…