Part 1: How can we landscape more sustainably?

Water Conservation for More Sustainable Landscaping

Sustainable landscaping is becoming ever more important. As our towns and cities heat up, our summers become hotter and drier and our winters become wetter, we need to think more about how we are to conserve and control our water supply.

In this first of three posts on the subject of sustainable landscaping, we will be looking at how we can conserve water usage, particularly in the dry months.

Lush, green lawns and foliage may be a feature of our environment that we have taken for granted. Visitors from nations with drier climates invariably comment on how verdant Britain always looks, even in the summer. But over the last few years, this has been changing and the summer of 2022 was a stark warning of what might lie ahead.

Let’s look at a few of the ways we can conserve water in the garden.

1. How and when we water the garden

Hose watering is fast and easy, but it isn’t a very efficient use of water. Although it comes with an initial cost, installing a drip irrigation system will massively save on water and is much easier than watering with a hose. If you can’t run to the expense of a drip irrigation system, avoid using a sprinkler as these are extremely high water consumers.

Choosing the best time of day for watering can also save water. The best time for watering is in the early morning when air, plant and soil temperatures are lower and there are generally fewer breezes: this will reduce the rate of evaporation. In hot, dry weather it will also prepare the plants for the heat of the day.

Conversely, planters and containers should be watered in the afternoon: studies have shown that containerised plants watered after midday perform significantly better than those watered in the morning.

Evening watering should be avoided, especially on foliage. This is because night-time temperatures are rarely enough to dry any moisture not absorbed by the leaves, and this can encourage the growth of fungal pathogens.

Watering the garden may be a daily routine, but does the garden need that much water? Generally speaking, a lawn only requires weekly watering and planted areas may be better at storing water than we realise. A moisture meter is an inexpensive tool that will tell you exactly how moist the soil is and whether you need to water it.

• 10-30% moisture means the soil is too dry and you need to water it
• 40-70% moisture means the soil is properly hydrated and needs no further action
• 80-100% moisture means the soil is too wet and shouldn’t be watered.

A grey water system is another way of recycling water from baths, showers, sinks and washing. This is perfectly acceptable for garden irrigation and will reduce the amount of water entering the wastewater system.

2. Choose water-saving containers

If you have a patio, terrace or roof garden, choose planters or containers that will help to conserve water. Terracotta is porous so water will leach through the pot and evaporate, while metal and resin will absorb heat and dry out the soil, particularly if they are dark-coloured.

Glazed ceramic and solid stone are the best choices as they retain moisture and keep the soil cooler. Dark-coloured containers should also be placed in areas with more shade, leaving their light-coloured cousins to enjoy the full sunlight.

Self-watering containers are another good choice, as they wick moisture up from a reservoir in the container base to evenly irrigate the plants over time. Adding water-retaining crystals to the soil will also help.

Larger pots that contain more soil are better at conserving water. You might consider planting several species in a larger pot rather than giving them a pot each, and the result can be quite spectacular.

If you are into hanging baskets, avoid open baskets with coconut or coir fibre liners. These will also allow water to evaporate too quickly. You can also place a pot or container underneath a hanging basket to collect and use any water that does escape.

3. Choose plants that aren’t so thirsty

Drought-tolerant plants will survive a hot summer with less watering, but there is a caveat – some will be very thirsty when they do get watered and in the long term may not save water. Equally, plants that require little watering may not be drought-tolerant.

Small, well-established and slow-growing plants generally require less watering. Varieties with leaves that are small or narrow, grey or silvery, leathery, hairy, curled or fuzzy also tend to require less watering.

Try to avoid plants with high fertiliser needs, fast-growing species and varieties with large leaves. Likewise, avoid planting during dry seasons, as waiting until the damper weather will give plants time to become established before the next summer.

When planting shrubs and trees, lay plastic over the soil and plant through it. This will help to conserve moisture and control weeds.

4. Use mulches and compost

Mulches are an excellent way of retaining moisture in the soil as they prevent evaporation – up to 70% of soil’s moisture can evaporate on a hot day if mulch isn’t used – discourage the growth of weeds that also deplete moisture in the soil, and retain essential nutrients.

A composting system is also another way of creating nutrient-rich and moisture-retaining soil additives. This doesn’t need to be anything fancy or expensive; even a black bin liner perforated with holes to allow air circulation will work.

5. Rethink lawns

Lawns require large amounts of water to stay green and healthy-looking and will quickly turn yellow in a drought. But as soon as the rain returns they will equally quickly return to a healthy hue.

If you can’t bear the thought of yellowed grass, consider reducing the area of your lawn by widening your borders or creating a Japanese-style gravel garden, or replacing the lawn with artificial grass.

While we’re on the subject of borders, gravel and artificial grass, let’s talk about landscape edging. Traditionally timber or concrete, landscape edging creates a clearly-defined border between planted areas and lawns, or between hard and soft landscaping. But neither timber nor concrete is particularly sustainable.

Granted, timber is in plentiful supply and comes from a renewable source, but with a relatively short lifespan it needs regular replacement, adding to the overall carbon footprint of this option, and once it has started to rot away, cannot be recycled. Concrete is most definitely neither sustainable nor recyclable.

But there are other options. Metal landscape edging is growing in popularity, and with good reason. They are lightweight and easy to install, strong yet flexible (meaning you can shape them to create stunning effects), weatherproof and 100% recyclable. They are also manufactured from metals with a high percentage of recycled content.

Made from aluminium, galvanised steel and Corten (weathering steel), metal landscape edging also gives a wide choice of design effects, ranging from the cool modernism of aluminium to the earthy tones of weathering steel that blends so well in rustic and urban, contemporary and industrial landscape themes. You can even get metal landscape edging for roof gardens and terraces.

Unlike timber and concrete, aluminium and steel edging is completely non-porous and will therefore prevent moisture from being sucked out of lawns and borders by gravel paths and stone, brick or concrete slabs and blocks.

This is the first of a three-part series on sustainable landscape design. Other posts in the series are:

• Part 2 – Rainwater Harvesting & Run-off Control for More Sustainable Landscaping
• Part 3 – Using Mulches & Growing Edibles in Urban Areas for More Sustainable Landscaping

Look out for these in the coming weeks!

We hope you will find this information helpful and interesting, and if you would like to find out more about aluminium and steel landscape edging, call the friendly team of experts at Kinley on 01580 830688 or email sales@kinley.co.uk.