WATER GARDEN CALENDER and CHRONICLES (October) by Peter May

What to do with the water garden in OCTOBER

This is probably the most important month in the UK for keeping on top of things water garden and gardening wise, so what should be done? Things can be looking a bit drab, any work done now has its dividends later on.

Any plants with leaves that are rotting into the pond should have these carefully removed. This should be an ongoing task for those of you in particular that have small ponds since they are so much more affected by the seasonal swings of growth and decay, cold and heat. With larger ponds, you can only attend to the fringes, but keeping these areas tidy and under control does make a big difference in the longer story of the ponds life.

It will be getting noticeably colder by the day and leaves have been falling for some time. This year an early quick change in temperature has started the leaf fall earnest, therefore for ponds surrounded by trees the leaf nets should be and covering the ponds already.

For those ponds too big to be netted, a bit of 'netting-off' of the surface and a bit of investigative dredging all helps to delay the day of a big clear out. Of course if the smell and the evidence on the dredging is that that day has now arrived then this is probably one of the most opportune moments to clear out – as long as it stays mild that is.

If the marginal plants in the baskets don’t look too over grown you can trim off the adventitious growth poking out the sides and try growing these on in separate containers, either to replace your old stock at a later date or as a present for someone. Any serious replanting can be left till spring.

If you are going to do a big clear out, don’t leave it too late otherwise all the frogs in the bottom of the pool will resent the upheaval and the plants, particularly the oxygenators, wont get settled in properly before it gets seriously cold. Also if you contemplate a big clearout, if the water is good, save as much of it as possible. Keep any fish or good beasties in it until then operation is complete.

Netting the pool or pond may be a bit difficult if the marginals are still at full height, so this may be the time to cut them back. Wild life and conservation pool owners usually prefer to leave the growth of poolside plants as cover for the wildlife ‘toing and froing’. A further quandary for fish keepers is that, although the tall poolside fronds of grasses and reeds waving in the autumn gales look attractive, they are also the perfect cover for herons. There is a perfectly acceptable compromise, however, cut the plants back to one third. This is good gardening practice because it means that those plants that were setting seed now divert their energies into food storage for next year. It reduces any risk of disease or over-wintering of pests, but also of course it diminishes the spray of unwanted seed all over the pool and garden. For instance did you know that there are between 175,000 and a quarter of a million viable seeds in your average Cats Tail/Reed Mace/Typha latifolia seed head and every teeny weeny little flower on a Water Plantian produces something like 40 or 50 seeds, which adds up to a quite a few thousand for every inflorescence stem.
With the plants cut back to one third, they make quite useful support and grip for the net.

As the temperature starts to approach 10°C you should be feeding the fish less and less. Koi need only have special high protein winter food or wheat germ. This is more easily digestible. At 7°C cease feeding altogether. They may still take food, by force of habit, but it wont be digested, only sit in their gut for the rest of the winter. Any uneaten food remains a time bomb of pollution ready to be set off in the spring as it begins to warm up and when the fish are at their lowest ebb.

Back to plants. Any soppy frost tender plants need to be rescued. You can plant up water hyacinths into soil and keep them in a frost-free greenhouse. Water Chestnuts and Frogbit need to be saved in their little nut form, particularly important to watch out for if you are having a bit of a cleanout. Any fancy frost tender lilies, like the Lotus, need rescuing too.

You should check your biological filter now, if you have one. If you intend to keep it running as much as possible through the winter, that is if you are banking on a mild winter, you may want to clean it out before the winter sets in. In this way it has a chance to recover and get going biologically before the temperature brings that activity to a halt. Therefore dont be too radical about the clean out (definitley dont use fresh tap water), you want the biological activity to continue and leaving a bit of muck behind works like a yoghurt starter. Besides if the weather really turns nasty and very cold for some time, then the filter will need to be properly cleaned right out to start again fresh and clean in the spring. An article will follow shortly on filter maintenance.

If you have seriously been considering building another pool, a waterfall, stream or such like, now is the time to get it done. Plan it and do it in one great swoop and you will have forgotten the pain of it by Christmas and all the evidence of the turmoil will be gone by spring. So what about it? This is the season for sorting. After Christmas, forget it. It all becomes a bit too much effort then until we are kissed by the faint, fair flickers of spring.