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Water-wise gardening -from drought to downpour

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Credit: Maureen Barlin

 Emma Cooper, author of ‘The Alternative Kitchen Garden: An A to Z‘ (Permanent Publications) shows how to solve our watering problems whatever the weather.

It seems there’s no such thing as perfect weather for gardeners. When the sun comes out, we worry that the plants aren’t getting enough water, and get aching backs from hefting the watering can around. When the heavens open, we worry about waterlogged soil and the run-off leaching all of the nutrients away. However, the way we manage our garden can really make a difference to how it uses and stores water, and this will make our lives easier into the bargain.

Tips for efficient watering

When lack of water is a problem:

  • Mulch. Bare soil around plants allows water to evaporate from the soil surface, so get creative with mulches and cover your soil. You can use anything from bark chips to plastic sheeting, with the choice depending on your budget and how you use your garden. Gravel and decorative stones are great for containers. For larger areas you could try Strulch, an organic mulch made from wheat straw that lasts up to two years, deterring both weeds and slugs at the same time.

    Straw mulch

    Straw mulch

  • Use saucers. It’s tricky to keep containers well watered during sunny weather so put saucers underneath pots so that water that seeps off can be reabsorbed by the compost later on. Remove saucers in the autumn so that plants aren’t sitting in water through the winter though, as this encourages root rot.
  • Use microclimates. Moving containers to a spot with some shade can make a big difference in the height of summer, as can giving plants shelter from the wind.
  • Add compost. Organic matter has a magical effect – it helps to store water in the soil and make it available for plants. It also improves overall soil health, and healthy soil means healthy plants, and healthy plants find it easier to cope with fluctuations in their water supply. So make plenty of compost, and add it to your garden beds.
  • Water at the right time. Water in the morning, or the evening, to give plant roots more time to absorb water before it evaporates.
  • Water well. Giving plants a little water every day causes them to grow shallow roots which don’t withstand drought. Drenching them every few days encourages them to grow roots down into the soil to find water.
  • Water wisely. Prioritise – make sure that you water containers, seedlings, fruiting plants and anything leafy. Perennial plants and tuber crops can go longer between waterings.
  • Stop mowing. In dry weather, let grass grow longer, and mulch the lawn with the clippings when you do mow. If the grass is still going brown, then let it – it will green up again once wetter weather returns.

Flood prevention tips

If too much water is the problem, then there are ways to help your garden cope with the influx:

  • Avoid hard landscaping wherever possible, replacing it with water-permeable surfaces to allow water to soak in.
  • Add organic matter – as mentioned above, it helps soil hold more water for longer.
  • Mulch. A surface layer protects the soil structure in heavy rain, again allowing water to sink in.
  • Plant green roofs on sheds and garages to slow water run-off, and add guttering to divert water into a butt.
  • Plant trees – not only do they use a lot of water, but their roots help to stabilise the soil structure and slow run-off.
  • Rain garden, Credit Roger Soh

    Rain garden, Credit Roger Soh

    Build a rain garden. These are areas designed to hold water and to slow run-off, and are planted with species that thrive in damp conditions. At their simplest they are depressions in low spots with suitable planting, but you can design rain gardens so that you link together your water butt, a pond and an overflow bog garden – all of which will look fabulous, even when built in containers or raised beds on the patio.

 

 

Water collection systems for urban gardens

Guttering

Credit: Burkhardt Reiter

Credit: Burkhardt Reiter

Guttering is a great invention, but modern plastic pipes aren’t what you would call attractive. Where downpipes are on view, rain chains are an attractive option, although they’re currently more popular (and hence more readily available) in the US. Rain chains are decorative metal chains that direct water from the guttering down into the drains or into your water butt. Options available include chains of little buckets, copper umbrellas or lotus flowers. They usually arrive fully assembled, so replacing a downpipe can be done in minutes.

Ifs and Butts

If you have a water meter then watering the garden becomes an expensive business, and it pays to install a water butt or two. Plain plastic butts are cheap, but there are plenty of prettier options on offer for small gardens. You can buy recycled oak whiskey barrels via the RHS online shop (http://www.rhsplants.co.uk/product/_/product/water-butts/water-butts/oak-whiskey-barrel-water-butt/classid.2000007178/) that hold 181 litres of water and add a traditional touch to the garden. There are slightly larger (270 litres) oak-effect plastic barrels on offer from Water Butts Direct (http://www.waterbuttsdirect.co.uk/decorative.htm), and a terracotta-coloured ‘Moroccan Beehive’ butt holding 150 litres is one of the decorative options on offer at the Water Butt Warehouse (http://www.waterbuttwarehouse.co.uk/decorative-water-butts). If none of these fit the bill then simply do a search for “attractive water butt” and you should be able to find the perfect one for your garden.

Automation

A water butt is great for collecting water, but it leaves the distribution entirely down to you. It is possible to buy automated non –pressurised watering systems that run off water butts – Amazon offers the Irrigatia SOL-K12 ‘fully automatic solar drop watering system’, http://www.amazon.co.uk/Irrigatia-irrigation-greenhouses-allotments-establishment/dp/B005AQRD90 which can cope with hanging baskets, greenhouses, raised beds and containers and well as the flower borders.

Hozelock make a Water Butt Pump that you can submerge in the water butt itself to pump water into the garden. http://www.hozelock.com/watering/garden-pumps/water-butt-pump.html  It’s part of their range of automated watering kits, which can be adapted to your specific situation.

There are plenty of options available so it’s important to do your homework and purchase a system that is right for your needs.

Hazel Silver recommends some other automated solutions to the watering problem.

Drip irrigation

Drip irrigation is a drip or trickle system, which disperses water on to or into the soil via a direct drip-by-drip action. It is worth investigating since over time it can cut water use by 90%, which both helps the environment and reduces water bills. In the microclimate of the urban environment, water is essential in the garden: buildings and traffic fumes raise the air temperature, so soil dries out quickly. Plus a lot of urban gardens are containerized because they sit on roof terraces – since containers need three times the moisture that flowerbeds do, a timed drip system saves a lot of watering.

Dripline irrigation. Credit: Marg O'Connell

Dripline irrigation. Credit: Marg O’Connell

The pressurized systems use plastic piping that releases water from emitters evenly spaced along its length; it is laid on the soil amongst plants. You will need about three linear metres of tubing per square metre of flowerbed and should set the gauge to release 3-4mm of water per day in hot weather; that’s three litres per square metre, which takes around forty-five minutes twice a day. If you’re watering containers, you can use smaller, more discrete ‘micro drip’ tubing and you should set the gauge to release one litre per day for every ten litres of soil. You can buy a sensor that switches the system off if it rains, for around £20.

Two of the best drip line systems are BioDrip installed by Watermatic http://www.watermaticltd.co.uk/irrigation-systems.html?section=irrigation-systems  and drip line irrigation kits which you can buy from www.easywatering.co.uk and install yourself. A small garden with ten square metres of flowerbed can be irrigated in this way for around £100.

Greywater Recycling

A reliable way of providing your garden with a continuous supply of water is to install a greywater recycling system. This will carry water from the bath into a filtering system that catches hair and skin cells, before depositing it in a tank. The resulting water is not completely pure so don’t use it on the vegetable patch. But as long as you don’t use hair dye in the bath or clean the bath with bleach, greywater is fine for flowerbeds; its only downfall is its lack of nitrogen, but this can be added easily in the form of Nitrate of Soda fertilizer.You can install a small system yourself from around £750, but you would need to regularly clean the filter. A more elaborate system, with a self-cleaning filter, can be installed in a larger family home from around £3,500.

And finally

Remember – whether too much water, or not enough, is the problem, the solution always lies in the soil. When you design your garden to store as much water as possible, you’re helping to prevent future problems, and saving your back!

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