Pond work for March

Last updated March 2018 from a series written by Alec and Val Scaresbrook for Koi, Ponds and Gardens magazine


This time of year the weather is famously unpredictable so we have to be ready for any eventuality. Prepare for new shoots, frosty mornings and garden pests…and focus on planning if it’s too wet to venture into the garden.

A timely tip for Koi keepers
In March, temperature is all important for Koi. Maximum, minimum and average temperatures dictate their metabolism and their behaviour in the pond. If your pond is well designed then its large volume of water plus its insulated cover should provide a stabilising effect. Monitoring is still essential in order to spot potential problems, and decide whether to adjust feeds. Remember to check that the fish are interested in the food and if not, stop feeding and try again in a week or so.

Spruce up for spring
Start weeding
Plants: spot the slime trails
Plant of the month – snowdrops
Fishponds: don’t ice up

Get set for spring

It’s still a quiet time of year generally for water gardeners and Koi keepers so it’s a good idea to make the most of your spare time, checking over pumps, lights and other equipment until spring arrives properly.

If you didn’t have time to clean and service your equipment before you put it away last year then an urgent inspection is in order. You can then buy essential parts (try Bradshaws Direct for filter spares, Bradshaws Direct for pump spares and Pondkeeper) and fit them in good time, and stock up on cable clips and other bits and pieces so that you can finish off installation in one go.

Outdoor features will be due for a brush and polish too. You may have stored any self-contained water features indoors, but if you only brought in the pump and left the rest outside it will need a scrub and shine to bring it back to its former glory. In particular, green and brown algae can disfigure some planters, and the pebbles of fountains, so if you don’t want the ageing effect it is worth giving them a quick scrub to spruce them up. A stiff-bristled brush and elbow grease is usually sufficient but if you use any cleaning fluids be careful to choose carefully and rinse thoroughly, as any residue or runoff could damage surrounding plants or harm birds and other wildlife drinking from such features.

If relentless rain stops you gardening, don’t let your preparations come to a stand-still. Wet days are a good excuse to browse your local garden centres, think about summer plants and garden features, and find inspiration for summer projects.

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Start weeding

You know when there’s been a mild spell by the weeds in your garden. In fact when weed seeds begin to germinate and their first shoots are visible, you know that the soil is warm enough for successful sowing of plants that you want. However, be sure only to sow hardy plants at this stage of the year – wait until frosts finish before sowing tender plants originating from warmer countries.

Do stroll around the garden looking out for weeds that are taking advantage of mild conditions and your winter absence from gardening duties. Be sure to pull up the creeping types, plus any that are flowering or seeding, before they multiply and make lots more work for you later, and before their roots go too deep into the earth for easy weeding.

Keep an eye on your bog garden, containers, and cracks between paving and alongside buildings. When the ground is wet, it’s easy to pull out the complete root if you grasp the stem firmly, and this cuts out work later in spring. If you move the leaves of garden plants to one side, you’ll often find weed seedlings growing there out of sight, where they’ll become too big to pull out so you’ll have to dig them out and risk damaging your garden plants.

For weeds in paving cracks, all you have to do is pour boiling water over them to kill the leaves and, if enough water goes down the crack, kill the roots too. If there is any regrowth, just repeat and you will soon weaken the plant and kill it altogether.

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Spot the slime trails

Mild spells mean that slugs and snails emerge from their hiding places to nibble on plant debris and tempting young shoots (but never of weeds, seemingly). Keep one step ahead of these creatures by keeping a look out for their slime trails and tracing them back to their hide-outs. The recess on the underside of plant pots is one popular hiding place, as is the underside of garden ornaments and stones. Pick up the offending creatures and drop them in a bucket of salty water to kill them; necessary for your garden’s survival. Alternatively, welcome thrushes and magpies, who both do a good clearance job.

You can also attract slugs to drown themselves. Make up a bait of baker’s yeast or dregs of beer in a container or special trap and sink this into the ground. Empty regularly. Or try purpose-made slug traps and attractants. Slug and snail poisons are a last resort because most are dangerous for other creatures, including your pets. If you do resort to using them be sure that the poisons and pellets are inaccessible to all but your target, and never use pesticides near your pond because they may seep or be washed into the water.

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Plant of the month: Snowdrops

Cheer up your garden with snowdrops (Galanthus), which shine bright at this time. Depending on the type of snowdrop, you may already have had a wonderful display or be about to enjoy their delicate flowers. If you didn’t plant any bulbs last autumn, you can still have snowdrops now because potted plants are often on sale (try Gardening Express. Plunge the pot into the ground or in a larger container with other plants for the best effect. Once the leaves begin to fade, plant up those in containers, and lift and divide other clumps of bulbs and spread them around the garden. You can also often buy bulbs ‘in the green’ ie with leaves, to be planted immediately but be sure the roots have not dried out before buying/delivery/planting.

For inspiration regarding which types to grow, find a ‘snowdrop walk’ near you. Gardens not normally open to the public in your area may be opened solely for their snowdrop spectaculars, so ask at your local tourist information centre for gardens open now, or visit further afield. We’ve visited Hodsock Priory, Nottinghamshire, and Rode Hall, Cheshire. For a comprehensive list across the UK, go to Great British Gardens website.

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Don’t ice up

It’s not easy to keep a pond ice-free manually so many fish-keepers install an electrically-powered pond heater to prevent some or all of their pond from freezing over. This ice-free area enables the ventilation of various gases from the decomposition of debris and the metabolism of fish which could build up to toxic levels if trapped beneath ice. It also allows for entry of oxygen from the air.

Also, whether you have fish or not, if you have a concrete pond with rather thin sides, these can be vulnerable to pressure exerted by ice. So a small ice-free area reduces the pressure.

There’s a variety of heating equipment from Bradshaws Direct and Pondkeeper but when choosing, take into account what other equipment is needed in conjunction with the heater, and what the running costs might be.

There are also low power alternatives to heaters, mostly floating devices designed to be connected to an air pump (or supplied with a small pump) to circulate some of the slightly warmer water from the depths of the pond to the surface. This keeps a small area of the pond ice-free.

If you don’t want to use a power source, you could resort to placing a pan of hot water on the ice every day. This is better than waiting for the sun to melt the ice, but it doesn’t maintain a permanent ice-free patch unless you’re able to (and want to) go out in the middle of frosty nights with your saucepan.

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