Part one of this tutorial covered the basics of how to water your garden effectively and to minimise wasting water. In this second part we describe the things we can all do to reduce the need to water with mains water in the first place.
Preparation is everything
Our number one rule when embarking on any gardening, is to know your garden.
Knowing where water drains to or from, where is baked by summer sun and where is shady and/or cooler is fundamental. It is of utmost importance to understand your soil type and whether you have sandy, silty or clay soil, or something in-between. This will enable you to choose the right plant for the right place. Plants are happiest in conditions that closely mimic their natural habitat and giving them those conditions will reduce their demand for watering. Use the RHS Plant Finder online. Type in your specific conditions and it will return a list of plants that should flourish. Or, when buying new plants, read the label at the point of purchase to make sure your choices are suitable.
Even with an educated assessment of your garden conditions, it’s possible to get things wrong. As professionals we also have to admit to this! Don’t panic if a plant doesn’t like where you’ve put it. Have fun experimenting with your planting and if you see something that isn’t as happy as it could be, don’t be afraid to move it when summer is over.
Getting to know what your plants are doing through the seasons is also a fantastic reason to sit back with a cuppa or beer, relax and watch the flowers. We say cheers to that!
Fill your borders, cover your soil
Sparse planting with lots of bare soil is a recipe for rapid drying out by the sun. Foliage acts to protect the soil surface from scorching rays so fill your borders!
Consider planting a tree canopy as well as lower growing herbaceous plants and shrubs. Trees provide dappled shade which cools the ground and reduces evaporation in hot weather, though be mindful that a dense canopy can create a rain shadow. If you have a small garden there are plenty of smaller trees to choose from. Take a look at our blog on choosing the right tree for the job. Once established, most trees are also fabulously drought tolerant, with their woody framework and large root network.
Alongside this, protect and condition your soil with an annual spring mulch of organic matter and you will increase the moisture retention of your soil. This is particularly important for sandy soils, but it will also act to ‘open up’ a clay soil, making it easier to rewet if it does dry out in the summer. Ideally use homemade compost or leaf mould but if you do need to buy it in always buy peat free compost. The added bonus is of course that this mulch will also ultimately feed your plants. Hurrah!
Cover hard surfaces
We always say that plants make a garden. However, did you know that they can also cool it significantly? Brick or stone walls, fences and hard landscaped areas all act to increase the overall temperature of our outside spaces during hot summers. They absorb the daytime heat and, in the case of bricks or concrete, release it slowly overnight. This will dry out your garden even further in a drought. Counter it by growing climbers up walls and fences and minimising paved areas. As we always say, plant more plants! Your garden will look better and we guarantee it will be a more comfortable place to be.
Make your lawn a tapestry
Grass is very drought resistant and can regenerate easily following water stress, but having a diversity of plants in our lawn can add to that resilience. Plants like self-heal, daisies, white clover and birds foot trefoil, once the scourge of lawns, are now welcomed as well behaved, low flowering plants enjoyed by a lot of passing wildlife. Many are the only green thing left on an otherwise parched landscape in the hottest of weather. Pop them in as plugs in the autumn then once they’ve established, mow with the rest of the grass though consider leaving it slightly higher to encourage flowering.
Time it right
For potted herbaceous plants* the best time to plant is early to mid-autumn, the next best being spring. In autumn the plant is entering dormancy so doesn’t require energy for lots of top growth, but the roots continue expand into the soil which retains summer warmth. The soil also tends to be more moist over winter, enabling the plant to establish with minimal watering.
Inevitably the seasons vary according to where you are, so watch what the weather is doing. In autumn wait for the temperatures to drop from summer highs, and ideally for some wet weather to have rewetted the ground. In spring, beware the fools’ springs that we seem to get so often in the UK and be sure that the wintry weather has passed before putting your new plants in. Evidently the ‘normal’ seasonal patterns are rapidly altering with the climate emergency, so exercise your judgement.
If you’re planting deciduous woody trees or shrubs, consider buying them bareroot and plant them anytime from November through to March. They’ll establish their roots in winter and will be stronger for it when the growing season commences.
*Before plastic pots, herbaceous plants were sold bareroot. Some nurseries still supply plants in this more sustainable way. Seek them out if you can. Follow the same timing instructions as for planting bareroot woody plants.
For most plants, planting larger specimens is a false economy. We would normally look for a minimum 1 litre pot size for herbaceous plants; any smaller and they tend to get lost in borders, their disappearance going unnoticed until you find a receipt for them hiding in a drawer. Anything beyond 2.5 litres we’ve found surprisingly hard to establish; what often looks like a large and robust plant tends to be a very fussy diva, yearning for its life back at the nursery it came from!
For trees and shrubs, it might seem counterintuitive but the smaller they go in, the faster the rate of growth, as they become accustomed to their new position and put down roots more rapidly. Trees put in as mere whips have been shown to eventually outgrow more mature plants over just a few seasons.
Water Harvesting and Storing
Water; it literally falls from the sky! An obvious statement, and yet we see so many gardens who don’t harvest this liquid gold. Look at your house, or any structure that rain falls on; sheds, garages, greenhouses. Put up guttering and away you go; what looks like a relatively small area can yield a surprising amount of rainwater. Water butts are available in ever more diverse sizes and shapes. This means that even small spaces are catered for. Always get the biggest you can get away with. There is no rule on how many water butts you can have in your garden, so the more the merrier!
Even with your rainwater harvesting system wrapped up, in dry and hot periods water doesn’t seem to go very far. Identify spaces in your garden that you can store rainwater in sealed bottles or any vessel you see fit. Nooks and crannies in gardens are there to be filled, whether that’s under benches or behind sheds. Every litre helps.
If you want to take your water conservation to another level, look at using grey water to water your ornamental plants. This refers to any water that is no longer drinkable but is still relatively clean. For example, water you’ve used to rinse your dishes, washed your vegetables in (ideally organic vegetables to be sure there aren’t pesticide or fungicide residues on them) or, shower and bath water. We collect the non-soapy part of our shower water and it’s kept our planters watered all summer, guilt free.
A word of caution though; do avoid using water that might contain a lot of detergent, because this can harm wildlife, in particular aquatic creatures.
Ongoing plant establishment and maintenance
Don’t mollycoddle plants
Plants become stronger when given a bit of tough love as they’re growing. Each time you water new and growing plants, be sure to give them a good dose of water, but do it less frequently. Roots then have to grow down in search for the water as it drains into the soil, becoming more able to cope with water stresses in the future.
Look after the soil
In addition to mulching annually, avoid overcultivating to keep soil healthy. Don’t dig or turn over soil unnecessarily. Your back will certainly thank you! More importantly, soil life will keep your soil aerated and porous, allowing plant roots to forage for the air, water and nutrients within it. Don’t compact your soil by regularly walking on it and if you hoe annual weeds off at the surface, you should be able to keep digging to a minimum.
We all have a responsibility to not be selfish with water, in our gardens and elsewhere around our homes. If we all follow this basic advice we can reduce the pressure on water supplies and what’s more, your gardens will be more resilient.