Walter - Water Gardening in Containers

Ken Walter

Few of us can resist the natural attraction of water. Whether in a still pool reflecting the summer sky or the tinkling rush of a stream, water provides a cool oasis in our busy world. Gardening magazines are full of beautiful pictures and elaborate plans for creating ponds, streams, and even waterfalls in your backyard, and bookstores now have whole areas in the gardening section devoted to water gardening. With good reason. Water gardening is relatively simple, and once your water feature is set up, it is very easy to maintain. This is probably the only type of gardening that rewards you more for doing less. Water gardens suffer no weeds and few pests; additions from the world outside the garden are usually welcome. The downside is that most in-ground water features require yard space and a significant commitment of time, effort, materials, and money to do the job right.

So its no wonder that, just as with soil gardening, most beginners wish to start small, with a more modest investment of their resources. And container water features are the best alternative for these beginners, as well as for people without yards who still wish to garden. A container large enough to hold a couple of plants and a few fish may be placed on a patio, on a porch or deck, on a sturdy table by a sunny window, at ground level, or even on a balcony or rooftop. It will support your favorite water plants, marginal and bog plants, and even fish. And because container water gardens present their own set of challenges, even experienced water gardeners may find this style of gardening interesting.

A typical container water garden has room for plants and even fish.

Large, in-ground water features have a couple of advantages over tub gardens: weather and water volume. Even in northern climates, a pond can sustain hardy plant and animal life throughout winter. This is because the pond usually wont freeze to the bottom, so plants that rest on the bottom will survive. Fish will become dormant and spend winter safely hidden below the ice and snow. And during the rest of the year, the larger volume of water in a pond will keep temperatures more consistent. Sun striking a small garden pond will heat it up much more quickly than it would heat a lake, and a lakes temperatures rise more rapidly in the summer sun than an oceans do.

Containers, which are situated above ground and lack insulation, hold little water. During winter they may freeze completely. And because of their small size and water volume, containers cool more quickly at night and heat up more quickly during the day.

As you begin to stock your container garden, keep these cautions in mind. With a little preparation, hardy water plants can be overwintered. Or treat your container garden as an annual garden, emptying it in fall and restocking in spring. While this is more expensive, you do get to experiment with many different plants this way.

In water gardening, as you can already see, an appropriate and fairly consistent water temperature is every bit as important as soil temperature is to regular gardening. Water plants will suffer and many die from exposure to inhospitable temperatures. Water gardening in smaller containers should not be started until outdoor water temperatures stabilize at 60F and above, well past danger of frost. Mail-order houses ship their plants to purchasers on a dated schedule based on average safe temperatures at the plants destination. And since many local garden centers get their plants from the same mail-order sources you can, they may not have plants available until it is safe to use them.

You can, of course, move your container water garden from season to season, but once you fill it with water each spring, that is where it should stay. It will be way too heavy to budge once it is filled, and emptying it to move it is very disruptive. You may already have a site in mind. Good. A few simple siting guidelines will ensure your success.

Most water plants require a minimum of 6 hours of sunlight daily. Wherever you site the water garden, make sure that it gets at least this much sun. If it gets less, some plants, especially water lilies, may not flower; others will not thrive. A location with late-morning and early-afternoon sun is generally the best for all plants within a feature. And the plants will do better if the container itself is not turned often, but is maintained in the same relative position to the sun.

As you look now for that sunny spot to place your container, consider the availability of water. You will have to fill the container, and then you may need to replenish its water often; in the heat of summer, the effects of evaporation will require almost-daily replenishment of some water in a feature of any size. If your container is truly small, this is no big deal. You will not need running water immediately adjacent to the container, though a hose will aid in cleanup. But consider a half barrel, the ideal container for a first experience: If placed in full sun, it may lose nearly a gallon of water a day. Maintaining a proper and consistent level of water is critical for plant life. The smaller the container, the greater the effects of loss of water level. So choose a site your garden hose will reach, if at all possible.

If you plan on lighting your water garden, adding a small fountain or waterfall, or using filters to maintain water quality, you will need access to electricity. And since water and electricity do not mix, the electrical circuit should have a ground fault circuit interrupter (GFCI). Under no circumstances should ordinary household extension cords be involved in the circuit. Not only are they dangerous, but they are un-sightly and can become a tripping hazard as well.

A water feature is best placed in a secure spot. Steps or ledges do not fit my idea of an accident-free location. If you are planning on adding a container water garden to your deck, make sure the deck is strong enough to support the container, all that water, and the plants. The surface on which you place a tub garden should be flat and must be level. And depending on the size of your container, keep in mind that it can be tripped over, kicked, stumbled upon, and otherwise disturbed by running children or unwary adults. So again, choose your site with care.

Consider safety when placing even the smallest feature, and then be watchful when children are near. Water, especially if it contains fish and other aquatic life, is even more attractive to children than to adults, and any water feature, no matter how small, presents a hazard to children. Those same children can also be a danger to your pond: In a small container, fish and snails cannot get away and may not be able to hide, and water plants of all sorts are easily damaged by being tugged, removed from the water, sunk, tipped over, or any of the other things a curious and active child can dream up. Supervision is the key. Also, check with your town officials. Although container water gardens are usually regulation-free, some towns have begun regulating garden ponds.

Any water feature is of more than passing interest to animals. Some, like frogs, turtles, and snails, are welcome additions. But be prepared for the questionable deeds of other animals and birds. Regardless of location, urban or rural, critters will find ways to slake their thirst and satisfy their hunger. Perhaps those in high-rise apartments will feel themselves secure against the squirrel, but birds are to be reckoned with anywhere. Animals all seem to delight in playing in water and even tipping an unstable container. There is plenty of technology available to help you control incursions should your patience be worn thin by pesky varmints.