In my efforts at xeriscaping (using drought-tolerant California natives) I've discovered some practical principles about sustainable gardening, here in Downey, that I'd like to share.
The first is that you don't need to xeriscape everything in order to save significant amounts of water. In deference to the 60-year-old star pine in my front yard, I use garden-tolerant plants in it's root zone and water it weekly. In the back, a quarter of the yard hosts two 60-year-old avocados and another quarter is lawn (a place to play with the dog), and they also get watered every week. But by converting approximately 2000 square feet into xeriscape, I managed to save, on the average, 30% of my water usage. That's a lot!
I hate my electric bill, and am doing everything I can to reduce it. So I planted three canary island pines to the west of the house because they're (1) fast-growing, (2) narrow, and fit the space (3) sidewalk-and-foundation friendly, (4) are beautiful to look at and (5) tolerate thinning quite well, which will be necessary as they're just off to the side of the power lines. They're not drought tolerant, and they don't particularly like our hard water, but they like our sandy-loamy soil and overall do very well with weekly water. I also planted an island oak out front. It's narrower growth habit fits the yard, and one day, it will be majestic.
In fact, most people think that xeriscaping means cactus, succulents, and rocks. Nothing could be further from the truth! Once you see the heat shimmering above bare, unshaded landscape, you realize that it's reflecting a lot of heat onto the home and into the neighborhood. Trees shade the ground directly, prevent ground-level air from heating up, and allow cooling breezes to blow through. There's a tree for every landscape, from desert willows to towering ashes, so don't sacrifice trees in order to save water.
If you're looking for maximum shade, plant tall trees along north-south lines - they will cast long shadows to the west and east during the morning and evening. My star pine shades the house in the morning and the road in the evening, and people love to park there.
But don't count on trees to shade your roof or walls in the middle of the day: At noon, the sun is high in the sky and the shade is a small puddle directly under the tree. For noon shade, you would be best planting a wide tree (like an oak) that will keep the property generally cool. As an aside, there are cool roofs that reflect sunlight and heat, and they come in all kinds of materials. Did I mention that I hate my air conditioning bill? We selected a cool roof when we re-roofed.
By focusing on California natives, I've enticed all kinds of birds, butterflies, hummingbirds and bees onto my property. Where it was once rather quiet, scrub jays, orioles, goldfinches, monarchs and honeybees busy themselves in my backyard, and the squirrels and lizards are an endless source of amusement (and frustration) for the dog.
And finally - style. There isn't a landscape that I don't like: woodland, beach scrub, meadow, prairie, desert - I love them all. In experimenting with different plants, I've managed to create everything from woodland to coastal scrub to English cottage garden (sometimes accidentally) and I've learned that there isn't a style that can't be reproduced (except maybe tropical) with the right choice of water-wise plants. So, what kind of landscape brings you joy when you look at it? You can achieve it and be water-wise too.