You can create a container water garden in one afternoon. Here’s how:
1. Locate a large container that can hold water. Many garden centers and nurseries carry containers made for water gardening or you can use a half barrel. If you use a half barrel, line it with plastic to prevent toxins in the wood from contaminating the water.
2. Place the container on a flat surface in an area that receives six or more hours of sun each day.
3. Select a variety of tropical plants for the water garden. Don’t crowd too many plants into a container. Two to three potted plants and some floaters will make quite an impact.
Hardy water lilies that perform well in container gardens include the miniature yellow Helvola, the classical Pink Sensation and red Fulgens. Good tropical selections include the blue Dauben and “sunset-colored” Albert Greenberg. Josephine, a promising new variety, has purplish-tipped, white blooms.Marginal plants include Native prairie cordgrass, arrowhead and iris-like sweet flag are marginal plants to complete the garden. Parrot’s feather, aquatic mint and Aeschynomene fluitans are charming novelty-like plants that don’t need to be potted and drape nicely out of a half barrel.
Floating plants include water hyacinth and water lettuce.
4. Pot your plants in containers filled with a heavy, packed clay and submerge them underwater. Use bricks or an old, terracotta pot to prop them off the bottom so the foliage is above the waterline.
5. Top off the container with water every few days as water evaporates.
6. When plants begin to grow, add a fertilizer tablet available at the garden center where you purchased your plants.
If algae develop, remove the water plants, empty the container, refill with clean water and replace the plants. Mosquitoes have not been a problem in container water gardens as the living plants keep the water from becoming stagnant. If they do develop, remove them by overfilling your container and letting the mosquito larvae run out with the water flowing over the top.
Aquatic plants won’t over-winter in a small container. Bring tropical plants indoors prior to the first frost, and keep hardy plants cool, but don’t allow them to freeze or dry out.
For more information see these Colorado State University Extension resources:
- Marginal or Bog Plants
- Selecting Plants for the Water Garden
- Floating plants
- Container water gardening