Aquatic Pond plant problems | Watercress died in garden pond
I have a small pond and recently all the plant watercress in it died. Please can you tell me what tests I can do to see why it might have died. Would it have died due to high nitrate levels?
Andrea Fletcher, Leeds
Peter May says:
Most people, in fact whole continents have the problem of watercress taking over, filling ponds and blocking waterways. It is usually quite difficult to kill once it is established and excess nitrates will make it flourish even more. However it is delicious stuff and it is not just us human beings that find it nice to eat.
If you have any snails in the pool or a slug and snail problem on dry land, I would look to these as the culprits.
It is very sensitive to cool air which slows down its growth, and if it is being grown like a marginal plant, it will tend to duck its foliage below the water level where it would be particularly at the mercy of water snails and even fish.
Thinking of 'duck', ducks love it too. There haven't been any itinerant quackers visiting, have there?
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