NOTHING ADDS MORE TO A GARDEN THAN WATER. Just ask the birds, frogs, and insects—oh, and human visitors, too. It’s a magical element, providing sustenance and visual fascination (auditory, too, if you can make it move). I just hauled my simplest, seasonal water gardens—two big, glazed troughs I fill spring through fall, then stash—out of winter storage, and ordered the plants I need to get the look above. The details (and no, nothing to worry about re: mosquitoes, really):
Yes, mosquitoes: That’s the most common question I’m asked when I lecture, when people see these photos, above and below, among my slides. “What about mosquitoes?” After that: “How often do you have to change the water?”
Making an “instant” seasonal water garden—meaning no plumbing required—merely requires a watertight vessel, water, and some floating plants to shade the water surface. I top up the liquid as needed during the season, but do not swap it out completely.
Containers can be anything that holds water, including galvanized cattle tanks; earthenware pots with glazing at least on their interior surface (like my big troughs) and no drainage hole; or some other found object.
Level the pot or pots first (use a carpenter’s level), while still empty, and insert shims beneath, such as from an old shingle or pieces of slate, to adjust and stabilize. Once you add water, forget moving the pot if it’s off-kilter.
I prefer to place these temporary water gardens in a part-sun spot, rather than full sun, to keep algae growth down. The shade provided to the water by the floating plants like Azolla (fairy moss) or Lemna (duckweed) that I use helps with that, too (sold by mail by places like Waterford Gardens). If your garden will go in full sun without a full cover of green, consider dyeing the water black with a non-toxic dye to help shade out algae instead (and hide all the underwater plumbing parts).
You can add fish if you like, but I don’t, since they are easy prey for cats, raccoons and the like. The frogs, above, add themselves at my place. Fish or frogs will eat mosquito larvae and mosquitoes, and I have no issue with insects, with my water pots in bright indirect light and covered in floating plants.
One funny note: If the pot is topped up to near the rim, heavy rains will cause overflow—and not just of water but also floating plants, which will likewise go overboard. Though they spread fast and make more, more, more all season in the water, you don’t want your velvety surface of green to go running down the path or into nearby soil, where the thousands of tiny plants would be impossible to recover…trust me, I have tried.
Don’t overfill, or instead cover the pot or scoop the green stuff into a dish and keep inside during big storms.
Hi Margaret, I just purchased a pot similar to the ones shown in the photo in your own garden. I remembered this photo from several years ago and saw the most beautiful ceramic trough today while shopping by appointment at my local nursery. While shopping I was thinking about what I could put in the trough, my nursery didn’t have any water plants and had planned to find this article. Low and behold it was on your homepage. The first thing my husband said while carting the heavy trough to its new home in the back, was that it would be a mosquito magnet. I live in an urban area of Seattle and not sure that frogs will take up residence. Do you have any other ideas of prevention. Regardless, I’m going to give it a try! Can you confirm the name of the green cover plant in the photo…is it duckweed? Thanks Margaret, I love your blog and your podcast.