Saving Water in the Garden

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Saving Water in the Garden

A saucepan filling from a hot tap

Why should Letchworth gardeners save water?

To conserve supplies
Particularly in hot dry years, watering gardens puts a great strain on water resources which in turn has an adverse effect on the environment.

To save money
Within the next couple of years every house in Letchworth will have its water supplied and charged for via a meter, so if you use less water, you also spend less money.

What can we do to help?

Techniques for saving water in the garden can be divided into several different areas –

A montage of water saving ideas
A mauve chair in amongst lavender

Plant Selection

What are the best plants for dry conditions?
Some drought-tolerant or drought-resistant plants have small grey or silver leaves covered in tiny hairs; this helps to reflect sunlight and reduce transpiration (water loss through leaves). Plants such as lavender and rosemary fall into this category.

Others such as succulents and cacti have fleshy stems or leaves that can store a reserve of water.

Vegetables such as carrot and parsnip have deep roots which can also be useful.

Here are some other plants good in dry conditions: Miscanthus Grasses, Osteospermum, Aloe Vera, Geraniums, Euphorbia, Thyme, Marigolds and Verbena

Tell us your favourites – email them to enquiries@ldga.org.uk

Pots & Containers

Which pots and containers should I use?
Plastic or glazed pots are best as water does not evaporate through the sides like it does with terracotta pots or wooden planters. If you like the look of terracotta or wood, then use a plastic pot inside or line with a piece of old compost bag with holes in for drainage.

Another good idea when growing in pots is to use water-retaining gel; when added to the pot’s growing medium it swells up as it absorbs water during rain or irrigation. Biochar, a charcoal-based soil improver, does a similar water retaining job but also aids soil fertility.

Using a few large pots with several plants in is better than a number of small ones with one plant each. This is simply because the larger volume of growing medium in a large pot won’t dry out so quickly. Group the pots together so the plants can shade each other, better still move the pots into the shade if it gets really hot.

A large number of pots all grouped together
Mulching around flowers

Mulching and More Mulching

What is mulching?
This is a technique where the area around plants, both in the ground and in pots, is covered by something that shades the soil, prevents water evaporating from the surface and helps to suppress weed growth. Mulching may be done with or without fabric.

Mulching with fabric – in this case the mulch is placed on a woven landscape fabric (also known as semi-permeable membranes or geotextiles) to a depth of 2.5cm (1”). Mulches used in this way are usually decorative. Some examples of decorative mulches are: gravel, horticultural grit, shingle, slate and other aggregates.

Mulching without fabric – in this case the mulch is placed directly on the soil to a minimum depth of 5cm (2”) ideally 7.5cm (3”). Mulches used in this way are usually biodegradable and will also add nutrients to the soil. Examples of biodegradable mulches are: bark chips, garden compost, mushroom compost, rotted manure, leaf mould and grass cuttings.

Water Collection

How can I get free water?
Rainwater harvesting from sheds and greenhouses into purpose-made butts or other recycled vessels is a fairly easy way to collect free water. You’ll be surprised how much you can collect in one year from even the most modest of greenhouses. You can also collect water from your house roof using a downpipe diverter kit.

Greywater is water, usually from your house, that has already been used for something else. This includes water from washing up and vegetable preparation. Water from cooking your vegetables may also be used – let it cool first, this will have added nutrients that have been lost during boiling. Although you can get detergents that can be used in greywater it’s probably best to use them just on your flowers and not your fruit & veg patch. Greywater should be used straight away and not stored.

When running the shower or hot tap waiting for the hot water to come through why not catch that water in a saucepan or bucket and use it on your plants.

Always use clean tap water for seeds and young seedlings as any impurities in stored rainwater or in greywater could cause problems.

Three water butts linked together
A piece of permeable walled hose

A computerised watering timer

Watering Techniques

What are good watering techniques?
The timing of your watering is important: never water in the middle of the day when the temperature is hottest unless the plant is visibly in distress then water immediately. Some say first thing in the morning is best, some say last thing at night. All in all morning is probably best because leaving plants and the ground wet over night when they are using less water could encourage slugs and snails and also allow fungal disease to form.

Another good idea is localised watering: use a can without a rose or a hose with a trigger nozzle to water the ground around the plant rather than the plant itself.
For larger plants, sink a perforated plastic bottle with the end cut off in to the ground next to the plant and use it as a watering funnel.

To promote deep root systems a good soak every 7-10 days is better than small amounts every day.

If you are willing to spend some money on your garden irrigation then soaker hoses are very useful for rows or larger areas of planting. Soaker hoses are permeable and allow water to flow through their walls at a controlled rate; they are connected to the water source with normal hose and may be laid on the surface and covered with mulch or, preferably, buried in the soil.
For more localised application, drippers may be used; these also deliver water at a controlled rate. A watering system can be made automatic by using a small computerised timer on the tap or water butt.

Never use a sprinkler as they can consume up to 1000 litres of water per hour.

Smarter Gardening

What is smarter gardening?
All the techniques mentioned so far may be considered smarter gardening; here a few more.

Keep your soil in good condition; incorporating plenty of compost or manure helps with moisture retention and encourages deep root formation.
Check the weather forecast, there is no point watering if it’s going to rain.

If you are not mulching, keep up to date with your weeding. Weeds use up water and nutrients that should be for your plants.

If you are growing runner beans, another good idea is to dig a ‘bean trench’. This is a trench dug well in advance and filled with kitchen scraps, newspaper, cardboard etc. and then back-filled. This gives a great reservoir for the beans’ roots to grow into.

Weeding with a fork
A post it note asking for your suggestions

Your Suggestions

What can you add?
We have gathered a fair number of garden-based water saving ideas from a wide range of sources, including some members’ suggestions, but we are sure there must be more. Let us know your ideas by emailing enquiries@ldga.org.uk

Some of the products mentioned above can be found at our Trading Store, see our Trading List for details and the full range of products stocked.

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