Ask Martha

Make your own outdoor water garden

The Colorado water lily is a good addition to your homemade outdoor water garden.
Ngoc Minh Ngo
The Colorado water lily is a good addition to your homemade outdoor water garden.

You don’t have to have a lily pond to grow water plants. With just sun, a little outdoor space and a container, you’ll be right in the swim of things.

“You can create a water garden in almost anything — just think of an aquarium,” says John Mark Courtney of Aquascapes Unlimited, a wholesale nursery in Pennsylvania that specializes in aquatic plants. There’s no need to have a lake or pond. And no special parts such as drains or filters are necessary. Just follow the tips below, and birds, dragonflies and other creatures will soon be drawn to this unexpected slice of nature. And so will you — these still waters can be deeply satisfying.

What you need

Courtney recommends water troughs, basins, planters, and even jumbo metal catering bowls, since large containers are easier to maintain. Look for vessels at least a foot deep and 15 inches wide, made of stone, ceramic, galvanized metal, stainless steel, or clay that has been sealed to hold water. Avoid copper, zinc, and other heavy metals, which could leach into the water and harm your plants. Glass, while attractive, will heat up quickly and is more high-maintenance since the water gets murky and will need frequent changing.

What to grow


There are three types of aquatic plants for containers. Submergents — such as anacharis (Egeria densa) and fanwort (Cabomba caroliniana) — live underwater and provide necessary oxygen. Emergent plants — including corkscrew rush (Juncus effusus “Spiralis”), golden club (Orontium aquaticum), and flowering water lilies and lotuses — leaf out and can bloom above the surface but are rooted in submerged soil.

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Floaters — such as water hyacinth, duckweed (Lemna minor) and fairy moss — cover the water’s surface, which helps keep it cool. The warmer the water, the less oxygen there is in it, making it susceptible to algae. Flowering plants such as water lilies and lotuses need at least six hours of sun. Add gambusias, or mosquito fish, which will feast on any mosquito larvae.

What to do in winter

In colder regions, you can treat your plants as annuals or bring them inside when temperatures drop below freezing. Remove spent foliage, and transfer plants to 5-gallon buckets of water in a cool garage or basement.

During winter, drain your container and cover it with plywood to prevent cracks until the following spring.

Adapted from Martha Stewart Living.