Nothing has more of an immediate impact on a garden’s appeal than adding a water feature. These come in a plethora of forms from multiple-acre wildlife ponds to gushing, resort-style waterfalls to tranquil pools of water in a quiet backyard. Contrary to expectation, a small water feature can be added to yards of practically any size and they are neither expensive nor difficult to maintain.
Let’s first address some common misconceptions – If properly stocked and maintained, the pond will not breed mosquitoes, nor will it be malodorous. Water features are not prohibitively-expensive; a patio-sized tub pond can be quite affordable and is easy to maintain – even easier than growing traditional land plants in pots – you don’t even have to remember to water them!
This is the flower of ‘Helvola’, one of the smallest water lilies.
One of the most common options for a patio mini-pond is a cask cut in half or some other similarly sized and shaped vessel. While these will usually hold water, it is best to line them with a suitable pond liner or find a tub made from plastic, as the wood can leach toxins into the water that can harm fish and plants. A tub at least fifteen inches deep and two feet across is a good minimum size. There are also commercially-available tubs designed especially for patio water gardens.
Aponogeton distachyos (water hawthorn) has an interesting, white flower and grows well in tub ponds. This mini-pond was made in a plastic pot with no drainage holes.
For the best plant growth, water gardens need to be sited where they will receive at least six hours of direct sunlight. Fewer hours is fine, but many aquatic plants require direct sunlight. If you’re planning to grow water lilies or lotus, six hours of direct sun is the bare minimum.
This mini-bog garden with Drosera rotundifolia (common sundew) was made from a plastic saucer designed to be placed under potted plants.
Tubs can also be used to grow bog plants. This tub filled to the top with soil and water is being used to grow Gunnera tinctora, a very large and dramatic bog plant.
With a tub pond, there are two options for planting – you can place suitable soil directly on the bottom of the tub and plant into it, or the plants can be grown in pots placed on the bottom of the tub. The former method is simpler, but the second allows more freedom in plant placement and can prevent some plants from taking over the whole tub. Aquatic plants do best with a heavy, clay garden soil without additives such as perlite (peat, perlite, and vermiculite will float out of the soil if you use potting soil and make quite a mess). Commercial aquatic plant mixes are also available. You can place a layer of sand or fine gravel on the surface of the soil after you have planted your plants to help keep the soil in place. For plants that prefer shallower water, pots can be set on bricks to elevate them.
Mosquitoes are a common concern for people who are new to aquatic gardening. Fortunately, they can be prevented from breeding in your water feature in several ways- the addition of fish such as goldfish, killifish, or minnows will eat any mosquito larvae that manage to hatch. You can also use a small pump to disturb the surface of the water- this will prevent the mosquitos from laying their eggs and stop the larvae from breathing. This method requires the entire surface of the water to be moved by the ripples, and works best with the addition of fish. The movement of the water needs to be balanced, enough to prevent mosquitos and not too powerful to damage the plants.
Petting a friendly goldfish.
A third option is to use insecticides in the water. This cannot be done if you have fish in the pond, as it will kill them too. An environmentally-friendly, non-toxic option is to use Bacillus thuringiensis, a bacteria that kills insects during their larval stage. It can be bought in commercial form called ‘mosquito dunks’, and is perfectly safe for use around people, fish, and other pets (unless you're raising insects).
Routine patio pond maintenance is simple; remove dead leaves and other decaying plant matter from the water and keep the water level topped up. You can use an automatic watering system and float switch to keep the level steady automatically. If you are using a pump to run a fountain or waterfall, the pump will need to be cleaned now and then to keep water flowing smoothly. The plants can be fertilised every month or two of the growing season using fertiliser tablets pushed into the soil. For those of you who live in places with winter, the best time to repot your plants is in early spring before growth resumes. If your winters are severe enough for your tub garden to freeze solid, fish and pumps must be removed before winter. Be aware that if your tub garden freezes solid, even cold-hardy plants might perish, depending on the kind of plant. Given the confined growing environment of a tub pond, rather than repotting your plants into larger pots, it’s better to trim the rootball and re-plant it in the same container with new soil.
If you choose to have fish in your pond (which I highly recommend, as they add beauty and movement as well as help keep your mini-pond free from aquatic insects and debris), in a typical, small, outdoor pond, you can have a few small fish without having to worry about feeding them (you’ll have to feed them for the first month or two while the pond matures), as the natural life in the pond will provide them with sufficient food. You can have more fish if you like, but any more than a few small ones means you’ll have to feed the fish.
Apart from that, there’s little to do other than enjoy your own little pond! Whether you choose a commercially-made mini-pond, build your own, or get really creative (a barrel pond as the base of a glass-topped table, perhaps?), a water feature can really make a splash in any sized garden.
Improvised containers can be used to include aquatic plants among terrestrials. Here we see ong choy (Ipomoea aquatica) growing in a bottle that is normally hidden behind other pots.