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Pond plants – Has my pond become invaded?

Hi, could you help me with my newly acquired pond please?

We have a kidney shaped “natural” pond in the garden, approx. 450cm x 300cm x 35cm (15ft x 10ft x 1ft) which has become a bit overgrown (no fish but some frogs/tadpoles).  As you can see, I have recently cut away some overgrown lawn which was growing into the pond to display the original pebbles.

I am more concerned about the plants.  I cannot seem to find what the ratio of plants to pond should be and whether there is too much here.  The bottom end has some small lilies and duckweed which are manageable (for now) but I am worried about the top half which is taking up half the pond. 

There seems to be some familiar pond plants (I think flags, king cups and a broad leaf plant – which might be the king cups' leaf) but there is some sort of unidentified plant working its way down the middle (plant id app says it might be European marsh wort).

If I need to divide up, I’m not sure how to go about this as it will be a solid heavy carpet of wet roots, so I won’t be able to pull it out and am worried about sawing into it as it is a liner.

It would be also nice to have a little water feature in the pond as the dragon/damsel flies seem to love this but I don't know if it is too shallow and will be prone to clogging.

If anybody help can help with the best course of action for the pond, i.e. plant to water ratio, how to divide up plants, identification of the plants, should I separate into containers, when is the best time to do it etc I would be very grateful …

Thanks in advance Della


  • You appear to have marsh marigold in there. It's difficult to ID anything else since: 

    A) I am a dimwit
    B) It's all green against similar greens

    It would be easier if you just removed 1 sample (eg Stalk, Leaf, Flower) of each plant you want to ID and photograph it against a contrasting background. 

    If it's a natural pond then it's already the right ratio. Nature tends to take care of all that. 

    I know you said no fish but they are hard to resist sometimes. If you do decide to add fish (and assuming you live in UK) you should ideally make it deeper in case it freezes in the winter. If those fish are koi then it would need to be deeper still. 

    If you go on this koi forum and ask then there are some very knowledgable people on there who may be able to ID the rest..

    Sorry i typed so much without actually giving you any answers. 

  • ButtercupdaysButtercupdays Posts: 2,739
    You want a pond, not a marsh. Your pond has a liner, so is not natural, only aiming to look like it is. Water and nutrients are more limited than they would be in a truly natural pond.
    Almost all pond/marsh plants are innately thuggish and will colonise as large an area as they can. Once they have used up the available water they will begin to struggle, but they will make a less attractive garden feature long before this, so you need to control them.
    The three you have do not need to grow in water, just in moist soil, so you could perhaps make a small bog garden at one end of your pond with some water proof liner and soil and just make sure it gets some water in dry periods. This would give you the chance to enjoy both the plants and the pond and you would have space for your water feature or maybe a dwarf waterlily and maybe another decorative plant too.

    I would start with the lousewort as it has spread the most and is the least decorative in a garden sense, though nice in its modest way, and a pair of scissors.
    Start at the edge, where it looks a bit yellowish,  carefully lift a little bit and cut through the roots, and keep repeating this until you have as much open water as you think you would like. You may be able to work underwater by feel alone, once you have had some practice, the way I can weed ground elder!
    I would restrict the iris to one nice clump. If you like it and have space you could plant some elsewhere if it is not too dry.
    The marsh marigolds will die back and disappear shortly after flowering, but you might want to reduce their numbers a bit, so that you could add a later flowering plant.
    Have fun and enjoy your pond :)

  • BrexiteerBrexiteer Birmingham Posts: 955
    My advice would be to take out the irises strip them all out and pop a few in a pot if you want. Under that water will be an area of solid root believe me I you pull one of the iris the whole lot will move. It's happened to my mates pond. He didn't tend to it for a few years as he wanted a natural wildlife pond but then one year he decided he wanted a few fish, his pond is about 12 × 6 he popped the fish in went up the next day the fish were exactly where he left them in the open water. Baffled but soon found out the roots covered 10 feet of pond
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