Marin Master Gardeners
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Ponds, When it comes to building a backyard water feature, start with a good plan

August 1, 2009
Julie Monson
 

The gentle splash of moving water in your own garden is as delightful on a cool morning as it is on a warm afternoon. Ponds and fountains have been primary focal points of gardens through the ages, from early Islamic courtyard gardens representing paradise, to enclosed abstractions of nature found in traditional Japanese gardens.

 

When we created our garden on the Inverness Ridge 10 years ago, I knew I wanted a Japanese-style garden with a natural, rock-rimmed pond, even though I knew it was unreasonable to expect we could have an authentic Japanese pond like those we had visited in Kyoto. Through trial and error I learned many lessons that may be helpful in designing and installing any kind of water feature in your garden.
I can't stress enough the need to integrate the pond into the garden's overall design. Don't just go out into the back lawn with a shovel and start digging. Start with a well thought-out plan. This means thinking about how and where you want to view the pond; where you will hide the filters, plumbing/pumps the pond will need; how large and deep the pond should be; and the basic design specifications.
I wanted a small pond to fit into our courtyard. I could as easily have chosen something contemporary, tile-lined and symmetrical. I also wanted moving water, so we planned not one but three small ponds, one feeding water into the other over rocky ledges. The moving water makes a continuous gentle splash, a lovely benefit that could as easily have been created by one slightly elevated rocky water source. Creating three small ponds was an unnecessary complication and expense.
I think of fountains as requiring sparkling clean water. My pond is not exactly murky, but since it contains water lilies and other plants and about a dozen goldfish, it is often greenish. I have to control algae, especially in summer. The permanent quest is for balance: of fish, plants and an efficient filtering system. In my pond, I also learned the importance of adding biological products that control algae, reduce decaying matter and help clear the water. These are available at some pet and pond stores. It took me a few years to work out the right balance, which results in slightly greenish but clear water and a healthy aquatic environment. I've learned to live with some algae on the bottom and side surfaces of the pond (the fish eat it), and pull out the "string" algae as it grows with warmer weather.
Two other factors assist with maintaining a healthy pond - shade and depth. The maple trees we planted 10 years ago now provide some shade during the summer. Water lilies and other water plants floating on the surface also create shade that helps moderate the temperature of the water.
Water temperature is also influenced by the water's depth. A shallow pond a foot deep, in full sun, without floating plants will become very warm on a summer's day. In my pond research, I learned that if we had raccoons - we do - we should make our pond 2 feet deep with fairly steep sides, to deter raccoons. This depth and partial shade works well to keep our pond cool in summer and warmish in winter. We also designed underwater benches on which to place potted water plants. The benches create hiding places for fish in the event of a raccoon invasion. We know raccoons visit our pond because we see their wet footprints; they haven't yet caught any fish.
My pond is a relatively simple one, yet I was caught unaware by how complex it became to design, build and maintain. I haven't yet discussed a filtering system, which is essential. For the novice, I strongly urge by starting with one or two of the excellent guides to pond building now available, even if you plan to hire a professional pond builder. The design of the pond will dictate future maintenance.
About cost: I had budgeted $10,000 to build our pond. In the end, it was more like $20,000, including excavation, all the large and small rocks, cement, wiring and plumbing, two filter systems (the first one wasn't satisfactory), and a crew for the initial installation and aquatic plants. Fortunately goldfish are cheap. A medium Japanese pond, as beautifully lined with boulders and plants as in those gorgeous photographs, is about $100,000.
We enjoy our pond. It fits our shady, Japanese-style courtyard garden and is a gently insistent reminder of both untamed nature and a controlled domestic garden. We can only control so much of what goes on in our pond. Occasionally, it is visited by small birds getting a drink, lots of dragonflies and skitter bugs, newts and, once, a red-legged frog. Would I do it again? Yes, only this time smarter.
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