WATER IS THE MOST IMPORTANT PART OF A GARDEN. Just ask the birds, frogs, and insects—not to mention human visitors. It’s a mystical substance that provides both nutrition and visual appeal (auditory, too, if you can make it move). I merely took my simplest seasonal water gardens—two large, glass troughs that I fill from spring through autumn and then stash—out of winter storage and ordered the plants needed to get the effect above. The specifics (and, no, there’s nothing to worry about in terms of mosquitoes):
Yes, mosquitoes: that’s the most typical question I get when people see these photographs, above and below, among my slides when I speak. “How about the mosquitoes?” “How frequently do you have to replace the water?”
Making a “instant” seasonal water garden involves only a watertight vessel, water, and some floating plants to shade the water’s surface. During the season, I top up the liquid as needed but do not totally replace it.
Containers can be anything that contains water, such as galvanised cattle tanks; earthenware pots with glazing on at least one side (like my enormous troughs) and no drainage hole; or any other discovered object.
While the pot or pots are still empty, level them with a carpenter’s level and insert shims beneath, such as from an old shingle or pieces of slate, to adjust and stabilise. If the pot is off-kilter after adding water, don’t move it.
To prevent algae growth, I like to position these temporary water gardens in partial light rather than full sun. The shade offered by floating plants like Azolla (fairy moss) or Lemna (duckweed) that I employ also aids in this (sold by mail by places like Waterford Gardens). If your garden will be in full sun and will not have a complete cover of green, try painting the water black using a non-toxic dye to help shade out algae (and hide all the underwater plumbing parts).
You may add fish if you like, but I don’t since they are easy prey for cats, raccoons, and other predators. The frogs above have decided to join me. Mosquito larvae and mosquitoes are eaten by fish and frogs, and I have no problem with insects in my water pots, which are in strong indirect light and covered in floating plants.
One amusing side note: If the pot is filled almost to the brim, severe rains will create overflow—not just of water, but also of floating plants. Though they grow quickly and produce thousands of little plants during the season in the water, you don’t want your velvety covering of green to trickle down the walkway or into neighbouring soil, where the thousands of tiny plants would be hard to retrieve… I tried, believe me.
Don’t overfill the pot; instead, cover it or scrape the green material onto a plate and keep it indoors during severe weather.