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Most
people agree that a wildlife pond is one of the most important
features you can have in an organically maintained garden.
Not only does it provide water for birds and passing mammals
to drink, but encourages many other beneficial animals to the
garden. Every organic gardener knows the value of having a
good population of frogs, toads and newts around, and
hedgehogs and foxes take their fair share of garden pests as
part of their nightly foraging.
One of
the most important features of a wildlife pond is that is has
plenty of vegetation to provide cover for all the creatures
that use the water in one way or another, whether for the
tadpoles of breeding toads, frogs, and newts, or to encourage
dragonflies and damselflies which are such efficient predators
of other insects. Most good wildlife ponds have a few inches
of soil over the liner, which enables the plants to spread and
increase as they will, but this in itself can bring problems.
With no limitations on the amount of water available, these
wetland species are inclined to grow very prolifically. Add
to this the fact that most are rooted directly into the soil
and not in containers as they would be in a more ornamental
pond, and it is easy to see how rampant they can become.
Great for the wildlife but inevitably some careful management
is needed to prevent the pond becoming a bog garden! This
slow transformation of pond to wet soil is a perfectly natural
occurrence in the wild, but in the garden we want to maintain
the status quo and ensure there is open water available for
wildlife at all times.
October
is one of the better months to perform the basic maintenance
that any pond needs, especially one brimming over with
wildlife. At all times of year there will be problems –
whenever we start to pull out plants and trample about on a
pond edge we will create disturbance for the wildlife there.
But by October most frogs, toads and newts will have removed
themselves to the rest of the garden and will be looking for
safe damp places to spend the winter months. Mature dragonfly
larvae have hatched and the breeding cycles of many of the
smaller pond creatures will be completed. Some male frogs
spend the winter months deep in the mud in the bottom of
ponds, but in general they will not have yet taken up these
winter quarters. There will still be many smaller
invertebrates, water beetles, the larvae of larger dragonflies
that take more than one year to complete their life cycles,
even the occasional undeveloped tadpole. But with care at
this time we can do some pond maintenance.
Choose
a time when you are not rushed – this can be an operation that
takes a little while - and equip yourself with a large piece
of light coloured plastic. This is ideal on which to place
the excess plants and the light colour makes it easier to see
any larvae, snails, water fleas or beetles that have been
inadvertently removed. If your pond is small it is likely
that you will able to reach the excessive growth of marginal
plants by leaning in and removing by hand, but in a larger
pond you may need to (very carefully) use a garden rake. It
is surprisingly easy to puncture your liner if your pond has one,
even if it is covered with soil, as I know to my cost! Try not to forget at any
time that your pond is only there because of this fragile
sheet of polythene or butyl. Liners are repairable with a kit
from the Garden Centre, but the hassle involved and distress
to the wildlife (and you) can be considerable. As you gently
pull or rake out the excess marginal plants, lay them on your plastic
sheet. Any animals that are immediately obvious can be put
straight back into the pond, but the vegetation should be left overnight
to allow most things to crawl back into the water of their own
accord. If you don’t have a friend who needs these excess
plants, compost them. Never be tempted to put them into a
wild wetland habitat even if they are native species.
In a
well-balanced pond, oxygenators can produce excessive growth.
These can also be gently raked out now and either donated to a
friend or added to the compost heap. Some ponds have problems
with alien invasive oxygenators such as parrot’s feather (Myriophyllum
aquaticum) or Australian Stonecrop (Crassula helmsii). These
must be removed and destroyed. The Crassula in particular is
causing enormous problems in our native wet habitats and has
threatened rare native species in many locations. These
plants can be left in a dry situation (in a garden shed for
instance) to dry out completely and die off before composting.
Water
lilies that have outgrown their space can be a further
problem. Their rhizomes are so vigorous and tough that they
can sometimes puncture liners. This is problem with one or
two water plants including the native yellow flag iris, and
the only thing here is use discretion if a plant seems to be
resistant to extraction. It is also difficult to deal with a
lily without emptying the pond, something that should be
avoided if possible. If the lily appears to be stuck fast to
the bottom of the pond there is a good chance that it has
rooted in and removing it will open up a leak. It is probably
best in these circumstances to leave well alone unless you
wish to clear the pond completely and start again although
there may be sections of the lily root that can be cut away
carefully with secateurs to reduce its overall area. In
general a good wildlife pond should have between one third and
one half of the surface covered by floating leaves, so if
yours hasn’t yet reached that stage there is no harm in
leaving a lily alone.
Try to
work methodically, slowly moving around the pond edge,
removing your excess vegetation as you go. This approach will
allow wildlife in the pond to move away from your activities.
It is also advisable to see this as a three stage process.
Tackle one third of the pond area (if there is a great deal of
excess growth, go for the most overgrown section first).
Repeat the process in October next year and the year after and
resign yourself to carrying out the whole process in three
stages. This way your water creatures will have time to
recover and will benefit from the fact there are still areas
of dense vegetation for them to take refuge in.
Once
you are satisfied with the progress you have made, take the
opportunity to improve the surrounding environment. A wildlife
pond should never be viewed as a stand-alone habitat, and logs
at the pond edge dipping into the water can provide an
attractive, damp environment for small frogs and toads as they
leave the water in summer. Long grass rather than a close
mown edge (or flat paving) will also make a safe refuge for
many emerging creatures.
The
value of water to wildlife can never be underestimated and a
well-balanced pond will be alive with insects and amphibians,
providing food for many other creatures that come to your
garden. Looking after your pond in an informed and careful
way will increase the diversity of wildlife there, and ensure
you have an army of helpers to keep your garden healthy and
pest free. |
