Water Gardens


Water Gardens

‘Dear Dr. Kris,
I would like to have a water feature garden in a large sealed pot with plants such as water lily or lotus but I am not sure how to tell the difference between these. Are there any other types of plants or even fish that I could grow in a water garden, what are the main factors to consider for this type of gardening?
Thankyou in advance,
Beatrice.’

From majestic flowers to the tranquil sounds of trickling water and the serenity of flickering reflections, all are a welcome presence in any garden. A water feature can range in size from a small water bowl or fountain, right up to a series of large cascading pools. Container water gardens are much easier to develop, maintain and rearrange, the bigger the water feature the more maintenance and work it will require.

“What is the difference between water lily (Nymphaea genus) and lotus (Nelumbo genus)?”

These plants are often confused with each other. A simple way to distinguish between water lilies and lotus is that the lilies will grow with the circular ‘lily pads’ that grow from below and float on the water’s surface, whilst the lotus has leaves that grow from stalks protruding up to a metre above the water line. In Indonesia water lilies are known as bunga teratai, and lotus are called padma. You will probably be better off growing water lilies, as lotus prefer the space of a large pond, pool or swamp.

Plants and Design

When designing a water garden you could use a combination of plants with contrasting foliage types, heights and textures, to create an interesting landscape. The water lilies will grow from below and sit on the surface. You could add the tuberous calla lily which will grow from below up to a metre above, with large flowers emerging from elongated stalks, then have the water lilies dispersed around this, and then finally you can add a surface plant such as water lettuce which will float on the surface and meander in the wind.

Before introducing water plants into the container cover the surface soil of the plants with decorative pebbles to stop excessive leaching of the mud into the water feature. The pot should be placed so that the root stock of the lily or lotus lies about 20-40cm below the water surface. If your water is too deep, use bricks or an upturned pot to stand your plant on.

Aquatic plants require full sun of at least 6 hours for consistent blooms. They will also need to be re-potted every two years to stop the pot becoming root-bound, which will also affect flowering. To get the best out of the lotus, it’s best to plant them in an earth bottom pond, because the more the lotus can run, the more it will flower. Water lettuce is placed free floating on the water surface so that it can float around, it will also multiply rapidly. Water lilies and water lettuce will help to cover the surface of the pond restricting algal blooms in the process. You will need to cover at least 50-70% of the water surface to reduce the proliferation of algae in your pond which would otherwise starve the water of oxygen.

You will find nurseries stocking an abundance of water plants in the Renon/ Sanur area especially on Jl. Hang Tuah, go there and have a look to see what is visually pleasing to you, as their display configurations will also give you a starting point for your own ideas.

Fish and Mosquitoes

You should also seriously consider adding small fish into the pond to keep the mosquito larvae in check. You won’t be able to enjoy the water feature if it is a breeding ground for mosquitoes, add a small pump/aerator to keep the water circulating. Solar aerators and solar fountains are relatively inexpensive and spare you the hassle of hooking up cables. If adding fish when you start your water feature you must add a conditioner to neutralise chemicals such as chlorine which may be contained in town water, and a water ager which will introduce bacteria beneficial for fish health.

If you wait a week or two the natural interaction between the plants, soil and water will produce a natural bacteria level that you can then add fish into. Start with a few minnows and one goldfish, it is much better to understock than overstock. Surface water plants will add oxygen and will help maintain water quality. Underwater plants/weeds which will grow from the pond floor to just below the surface such as elodea can be added as a natural food source for goldfish. In the absence of fish there are also mosquito dunks which are small tablets you can add to the water that will prevent the mosquitoes breeding.

Water Quality

A water garden is a mini ecosystem, that reproduces nature, but on much smaller scale. It is important that the system is maintained within a healthy balance. By occasionally removing 25-50% of the water and adding new fresh water you will help dilute any potential chemistry problems, ammonia build up from fish waste, nitrites and nitrates as well as algal growth. Regular partial water changes and the removal of dead leaves/organic matter are the primary duties in maintaining a healthy pond.

If you are having recurring problems with green murky water you will have to reduce algae growth by increasing surface cover. This can be done by adding more water lilies. Submerged plants (elodea), and floating plants (water lettuce) will also compete with algae for nutrients and a few water snails and sucking catfish (which are only small) will also consume algae and aid the balance of the system. Otherwise move the water bowl to partial shade, but then you will have less potential for lily flowers.

If your fish are breeding or tadpoles are present this is an indication that you have the system in perfect balance. With the system in balance, the combination of mosquito larvae, pond plants and naturally occurring bacteria will mean that you may rarely need to feed the fish at all. Goldfish will also appreciate the occasional live worm or boiled pea! Make sure you touch the worm or pea on the water surface to alert the fish, you don’t want the food falling to the bottom uneaten where it will slowly decompose and dirty the water.

If the water develops an unpleasant odour you will need to remove the plants and fish to a temporary tank, and scrub your water feature clean without using detergents. Adding 100% clean water, without appropriate water treatment would be disastrous for the fish. Refill with fresh water using the appropriate water conditioners and water ager as at the start.

Good luck and happy gardening!

Dr. Kris
Garden Doctor
Contact: dr.kris@ymail.com
Copyright © 2015 Dr. Kris
You can read all past articles of Garden Doctor at www.BaliAdvertiser.biz