AUTUMN POND MAINTENANCE
In the London Borough of Richmond upon Thames, allotment holders are permitted to create a pond on their plots using a liner or existing container e.g. old butler sink.
Benefits of having a pond on your plot:
1. A habitat for wildlife – ponds are one of the most important habitats for wildlife, especially in urban areas. They provide vital refuges for some of our protected species, (e.g. Common Toads), and stepping stones across a wider fragmented landscape to allow species to move between suitable breeding and terrestrial habitats.
2. Pest control – ponds attract a variety of wildlife, including birds and predatory insects e.g. dragonflies and amphibians. All these species help with pest control of your crops, reducing the need for manual or chemical pest control.
3. Pollination – ponds attract pollinating insects, for example bees and hoverflies, which are attracted to water sources which contain minerals to drink. This will help to increase your crop yields e.g. tomatoes.
4. Aesthetic appeal – ponds are a nice addition to your plot, enhancing the visual appeal of a plot.
Autumn maintenance tasks
1. Remove fallen leaves from the surface of the pond regularly. Alternatively, cover the pond in a wildlifefriendly net but ensure it is raised off the ground to allow animals to get in and out of the pond safely.
2. Thin out excess oxygenating pond weed. Aim for 40 – 60% oxygenating pond weed in the pond yearround (this is especially important for male Smooth Newts, who need space to perform their mating ‘dance’). Place excess weed in a trug bucket with an inch of water in the bottom and after a minimum of 30mins remove the weed and either donate to fellow plot holders or compost. Return the inch of water to your pond, which will contain damselfly larvae etc. This can be repeated throughout the year.
3. Cut back any rotting plant vegetation e.g. Flag Irises and Marsh Marigold leaves. You can leave more woody stems from Water Mint and Loosestrife as the leaves and seedpods are good for overwintering invertebrates e.g. ladybirds and spiders.
4. Continue to remove duckweed and blanket weed, although growth will slow over autumn. See below for tips on how to improve water quality with barley straw bales and watercress (in spring).
5. Avoid topping up the pond with water from October – March as it is better for it to fill with rainwater.
6. September – October is the ideal time to perform any major pond restoration tasks e.g. replacing liner, removing excessive sludge at the bottom of ponds. Common Frogs may be brumating (similar to hibernating) from November – January and spawning from February – March, so it’s important not to disturb ponds during this time where possible.
7. September – October and March – April are ideal times to build new ponds.
Recommended materials and plants
Mini straw bales for helping to control algae growth in new ponds naturally:
https://www.watersidenursery.co.uk/barleystraw-minibales
Add one to small ponds or two to large ponds in Spring and Autumn each year. Remove after six months and leave by the edge of the pond for invertebrates to crawl back into the pond – then the barley straw can be composted.
Watercress: in spring buy a punnet of organic watercress from your local supermarket and just throw it into the pond (John Hurd’s is a popular brand – available at Waitrose).
Topping up the ponds with water: – Ideally use collected rainwater from a water butt. – Alternatively use tap water with EcoPond Chlorine Guard (available in 250ml or 2.5L). If you have containers and the time, leave the tap water in a bucket for 24 – 48hrs before adding to the pond with EcoPond Chlorine Guard). – Do not use water from Beverley Brook, it is heavily polluted with raw sewage.
Suppliers of pond plants and materials
Waterside nursery: https://www.watersidenursery.co.uk/
Lincolnshire pond plants: https://www.lincsplants.com
Pond liners and underlays: https://bradshawsdirect.co.uk/pond-liners/
and information on which liner to select (choose the most expensive liner you can afford as it will last longer): https://bradshawsdirect.co.uk/blog/which-liner-should-i-choose/
Recommended plant species
Emergent/ deep shelf
• NYMPHAEA sp. (Dwarf Water Lily)
• IRIS PSEUDACORUS (Flag Iris)
Oxygenating weed (fully submerged in the water)
• CERATOPHYLLUM DEMERSUM (Hornwort) Rafters (float across the top of the pond)
• RANUNCULUS AQUATILIS (Water Crowfoot)
Shallow shelf at the margin (max. depth 10-15 cm)
• MENTHA AQUATICA (Water Mint)
• MYOSOTIS SCORPIOIDES (Forget-me-not)
• CALTHA PALUSTRIS (Marsh Marigold)
Around the edge of the pond (like damp soil):
• GEUM RIVALE (Water Avens)
• LYCHNIS FLOS-CUCULI (Ragged Robin)
• LYTHRUM SALICARIA (Loosestrife)
• SUCCISA PRATENSIS (Devils Bit Scabious)
Additional resources
BHAS website: https://eastsheenallotments.com/a-pond-for-every-plot/
Freshwater Habitats Trust https://freshwaterhabitats.org.uk/advice-resources/garden-pond-advice-hub/
RHS – making a new pond https://www.rhs.org.uk/ponds/construction-and-repair
Wildlife Trusts – a pond for small places https://www.wildlifetrusts.org/actions/how-create-mini-pond
Advice on maintaining or fixing a problem pond – we are here to help, please email [email protected] and we can offer friendly advice on keeping your pond in good condition and provide free native pond plants to improve diversity.