Easy Ways to Grow Aquatic Plants and House Fish without a Full-Pond Commitment
Looking for a way to dip your toes into the world of water gardening before jumping in head first? A container water garden is the perfect solution. These miniature ponds provide all the components of a large-scale feature (aquatic plants, moving water, fish, and the ability to draw wildlife) on a smaller, less intimidating, scale. Best of all, they can be created without the aid of shovels or a backhoe.
Containers designed to hold water are often referred to in the trade as water bowls. They are glazed inside and out, have no drainage holes, and come in a variety of colors, shapes, and sizes. Other vessels such as whiskey barrels can also be modified to hold water if a plastic liner is added to prevent leakage. When choosing a container, consider the size of the space where it will be placed, the type of plants you want to grow, whether fish will be added, and if a fountain will be used.
Aquatic plants can be divided into four groups based on growth habits: floating, submerged, floating-leaved, and marginal. When choosing plants for your container water garden, it is important to note that a good combination will create a more balanced ecosystem, which will in turn deter algae growth and promote fish health.
Floating plants such as Water Lettuce (Pistia stratioites) and Frogbit (Hydrocharis morsus-ranae) have leaves which float above the water surface and well developed root systems that trail in the water beneath. They are excellent at filtering and shading the water.
Hornwort (Ceratophyllum distichum) and Cabomba (Cabomba caroliniana) are examples of submerged plants (plants that grow with their roots and leaves completely beneath the water surface). These plants oxygenate the water and feed on excess nutrients, thereby reducing algae growth.
Floating-leaved plants include waterlilies (Nymphaea spp.) and Water Hawthorne (Aponogeton distachyos). Growing with their roots anchored in the soil and their leaves floating on the water surface, they also shade the water and provide protection for fish from predators.
Marginal aquatics grow in shallow water or boggy soil at the pond’s edge and include hardy species such as Lotus (Nelumbo spp.), Cattails (Typha spp.), and Water Iris (Iris spp.), as well as tropicals such as Violet Stem Taro (Colocasia esculenta ‘Fontanesii) and Umbrella Palm (Cyperus alternifolius). These plants feed on nutrients in the water and provide a habitat for frogs and insects to lay their eggs.
Two primary methods are used to plant water bowls. The first is to add a heavy clay loam to the container (soil mixes containing light materials such as peat and perlite should be avoided as these will float to the surface), plant a marginal or floating-leaved plant directly into the soil, add a layer of gravel or polished rocks, and fill the container with water.
A second method is to fill the container with water and place individually potted marginal and floating-leaved plants inside, leaving space for fish as well as submerged and floating plants. A small fountain can be added if the container is placed near an electrical outlet where a submersible pump can be plugged in. If fish are added, opt for small varieties such as goldfish and avoid large species including koi, which will quickly outgrow the container. A good rule of thumb is to add one inch of fish per gallon of water.
Water bowls are easy to maintain. Regular tasks include fertilizing marginal and floating-leaved plants monthly during the growing season with an aquatic fertilizer (submerged and floating plants feed on nutrients in the water and do not usually require additional fertilizer), removing spent leaves and blooms, and monitoring for mosquito larvae. Products containing beneficial bacteria that feed on these larvae can be added monthly. If algae become a problem, algaecides that are safe for fish and plants can be added weekly to maintain water clarity.
Winter care in colder climates includes draining the container to prevent expanding ice from causing it to crack. Hardy plants can be mulched heavily and stored in an area where they will not dry out, while tropical marginals can be moved inside to a sunny room or simply treated as annuals and purchased again the following year. Tropical waterlilies will often form tubers which can be stored in damp peat, sand, or water in a cool garage or fridge for the winter months. Fish can be kept in an aquarium indoors.
So what are you waiting for? Toss aside that shovel, fill up a water bowl, and jump into the world of container water gardening – the water’s fine!
Photos provided by Aquascape, Inc.