The sight of crystal clear water, fishing swimming around, and decorative pond plants is a truly wonderful sight to behold.

The aim of the majority of pond keepers is to maintain this relaxing, tranquil image in the forefront of their minds. The last thing anyone wants is a fish pond containing decaying and lifeless aquatic plants.

Not only is this unsightly, but it also impacts upon the pond water in many ways; including: increased pond sludge, increased levels of ammonia and nitrite, changes to the pH of the water, increased levels of heterotrophic bacteria etc. All these eventually affect the health of pond fish and pond life.

Generally speaking, aquatic plants are hardy and not as easily bothered by many of the pests and plant diseases that affect their land dwelling cousins.

Unfortunately, however, they are susceptible to illness and disease, just like you and I. As with most things relating to pond keeping; prevention is far better than having to find a cure.

Maintaining healthy water plants requires some careful planning and keeping a careful eye out for tell tale signs of plant disease and plant pests.

If these tell signs raise their ugly head then you need to act quickly and decisively. If you do this then you should be able to keep your water garden pond in great shape.

Want A New Lodger? Insects Love Aquatic Plants

Insects are a common pest, both for land dwelling plants and aquatic plant life.

Certain insects use the leaves of the pond plant as a place to lay their eggs. These hatch into caterpillars; which as we all know love to eat plant life. One such example is the China Mark Moth, whose 1 inch (2.54cm) long, cream coloured caterpillars, emerge towards the back end of summer.

These voracious creatures are responsible for biting oval shaped holes into plant foliage. They use these pieces of foliage to make a protective floating house, from where they can continue to eat pond plants and grow; eventually becoming a pupae.

The best solution for preventing mass scale destruction to your aquatic plant life is to remove them from your pond. As you see their floating homes, simply remove them from the water.

The beautiful Water Lily, one of my favourite pond plants is a particular favourite of insect attacks. One such culprit is the larvae of the Water Lily Beetle. The brightly coloured grubs (black with a yellow belly) will quite happily eat their way through the leaves of water lilies. The damage, in the form of large holes, eventually causes the leaf to wither die. If you see any leaves like this then remove them and destroy them ASAP; before they fall off and rot on the pond floor.

Fortunately the Water Lily Beetle prefers to lay its eggs in large expanses of water, leaving the smaller garden pond in relative safety.  This prolific brown beetle is capable of depositing between 3 and 4 batches of eggs during the summer season.

If your pond does become infected by these pesky creatures then you will need to hose the infected water lilies down, after systematically removing any damaged leaves. As the beetle can lay several batches of eggs, you may need to repeat this several times during the summer.

During really hot weather your aquatic lily plants will often come under attack from Water Lily Aphids. They appear in their droves and manifest themselves on water lily leaves, stems and flower buds.

Due to the large colony of these tiny aphids your plant life will be severely weakened. You may notice absent flowers or distorted growth patterns. These aphids are very similar in size to the more common vegetable black fly.

You get rid of these pests in exactly the same way that you got rid of Water Lily Beetles i.e. hose the plant down, after having removed any damaged leaves. Your Koi, goldfish and other aquatic life will savour these tasty snacks.

Continuing with the theme of insect pond pests, the Leaf Miner Midge is another example of menace to aquatic vegetation. It isn't fussy and will pretty much chew away on any pond plant species.

These transparent, small maggots are difficult to see, but there is no mistaking there presence in your pond; they eat their way through the soft tissue of the plant, leaving a skeletonised leave behind.

If you are looking for a treatment then things aren't looking too good. The only solution is to pick off the damaged leaf (leaves) and get rid of them.

Water Lily Crown Rot

This highly infectious fungal infection is very similar to potato blight, and is capable of totally destroying an entire pond full of water lilies.

TIP! Prevention is better than cure. When you buy new water lily plants always inspect them for signs of insect infestation, or disease. In the case of Water Lily Crown Rot you will see a black, soft spot on the rhizome of the lily.

An infected water lily will have leaves that become a yellow colour, prior to them coming away from the crown. The crown eventually starts to smell and becomes a black colour.

Unfortunately, the only remedy is to remove infected plants from the pond water ASAP. As stated earlier, Crown Rot is highly contagious to other water lilies.

The good news for water gardeners, however, is the general resilience that aquatic plants show. Unlike land plants, where pesticides can be used, pond plants have to be handled differently. After all it isn't a good idea to spray pesticide chemicals into a fish pond.

A vigilant approach to pond keeping and careful observation of your pond should help you to notice insect infestation or diseased plants. If you act quickly then you should be able to maintain your beautiful water garden pond.