It seems crazy, doesn’t it? One minute it’s pouring with rain and the next we’re facing hose-pipe bans. So how do you know when your garden plants need a good drink, and how often should you water them and when?
With heightened awareness of climate change, you’ll discover taking a two-pronged approach to your watering regime can make positive changes to the way your garden and the plants you grow.
Using less water and drought-proofing your garden doesn’t mean compromise either; plants that can cope with extended dry weather are every bit as beautiful as more traditional choices.
It might be that you’re already growing several drought-resistant plants, trees or shrubs in your garden but there’s always room for improvement. Now’s a perfect time to tweak your plant choices, fine tune your water conservation approach and do away with the hose-pipe ban blues by following our favourite labour-saving watering tips.
When is the best time to water garden plants?
Should you water plants at night, or in the morning or perhaps the afternoon?
Let’s put it like this, imagine you’re going jogging – are you more likely to sweat more running on a cool morning or in the heat of the midday sun?
Plants start using water in sunlight, sucking it up through their roots and sending it to the leaves where it’s released through microscopic holes, rather like sweat. And there’s your answer.
The best time of day to water plants is early morning. This allows roots to fully absorb moisture rather than it going to waste through heat or evaporation and lets them process water more efficiently.
If you’re not an early bird, the next best time to do your watering is in the late evening. But, that means you’ll run the risk of encouraging diseases such as powdery mildew or luring thirsty slugs and snails out into the twilight; the kiss of death if you’re a hosta grower.
How often should you water outdoor plants?
Different plants have different watering needs, so how often you should water plants very much depends on what you grow. We’re often asked by customers whether they should water plants every day? Or should you water plants in the sun, when it’s overcast, once a week or fortnightly? There are no hard and fast rules since watering is weather and plant dependent.
The good news is that even small changes can prevent water waste and have no detrimental impact on the health of your garden plants. In winter and late autumn, you won’t need to water your grass, garden plants or containers as natural rainfall obligingly does the donkey work for you.
However, as plants begin to actively grow in spring, watering once a week is fine in average weather. If there is an impromptu mini-heatwave, up the watering to two or three times a week as long as it lasts.
Tell-tale signs your plants are gasping for a pint or two are:
- wilting leaves
- flowers that are hanging their heads
How much water to give plants
It’s better to give most plants a good drenching weekly than light or sporadic watering. It’s especially true of lawns that appreciate a heavy soaking once a week to encourage grass to root more deeply.
If you think about it, lawns are made up of millions of individual plants all gasping for water and although in drought, grass browns quickly and looks dead, fortunately, lawns recover very quickly with the first rainfall.
How to water your plants
Mature trees and shrubs rarely need watering at all because they’ve already developed extensive roots to seek out the water they need. Older, well-established fruit trees can fend for themselves too, but may need a helping hand in prolonged dry weather. A good weekly soaking should be ample.
Newly planted trees, shrubs and perennials need frequent watering to help them settle down. The RHS recommends watering every 7-10 days using two and a half 10-litre watering cans per square metre. (That’s roughly 24 litres per sq. metre.)
And let’s not forget fruit and vegetables! Vegetable and salad crops just can’t cope with water shortages so you’ve no choice but to water generously as often as needed. Soft fruit and newly planted fruit trees also need watering at least once a week to help them establish and help the fruit swell.
How to save water in the garden
Here are our top tips on how you can save water in the garden; they’ll not only save you money but are labour-saving too.
- Add organic matter to flowerbeds in late autumn, winter or early spring – Mulching beds and garden planters with a thick layer of organic material, such as homemade compost or rotted manure, about 5-6 cm deep helps trap moisture in the soil and reduces water loss.
- Reuse household water – Soap and washing-up water are fine, although avoid any water with heavy doses of bleach or chemicals.
- Invest in water butts – Collecting rainwater is free and plants respond better to pure rainwater because it lacks hard elements. The larger your garden, the more water storage containers you can have, but even small courtyards have room for a slimline water butt.
- Try to avoid sprinklers – So much water is lost in evaporation so it’s better to hose areas directly.
- Automated irrigation – This can be timed to come on in the early hours of the morning, delivering water to the base of plants where they need it most and it is most easily absorbed.
- Invest in a seeping water hose – Look for one programmed with a water timer to come on in the wee small hours for maximum results.
Drought tolerance doesn’t mean plants can get by with no water at all, but it does mean they are more able to survive prolonged periods of dry weather with much less water than traditional lush perennials.
Drought resistant perennials
Most silver-leaf plants not only have built-in sunscreen (that’s why their foliage has that seductive grey or silvery sheen), but many of them come from hot climates such as the Mediterranean with little summer rainfall, so they have an inbuilt ability to thrive in drier conditions.
Growing drought-busting plants doesn’t mean sacrificing form for function either, because there are a huge range of beautiful but tough perennials to choose from. Here are just a few you might like to try.
Festuca: Often called bluegrass, Festuca is a stunner for pots and sunny gardens, making neat, spikey mounds of metallic blue. If you can offer it a sizzling spot, the colour is heightened in full sun.
Feather reed grass: Is far easier to say than Calamagrostis, but if you’re looking for a fabulous-looking garden trooper that can cope with drought, wind, hail and everything in between and still look stunning, this is the grass for you. Vertical fresh green stems steadily rising in height from spring are tipped with charming feathery heads of purple-green, and once established, it’s reliably drought-resistant.
Mexican feather grass: Better known as Stipa, it has great drought-coping tools: tactile, tall, airy stems sway gently in the breeze adding height and structure to summer borders.
Pampas grass: Cortaderia is back in fashion and about time too! It’s easy to grow and is as tough as old boots. It can take wind, rain and, yes, drought, and also has the bonus of providing a natural nesting habitat for birds.
Rosemary: Rosemary is not just a fantastic drought-tolerant shrub, it’s also very handy for foraging a handful of aromatic sprigs to add to the Sunday roast. From spring to early summer, tiny powder blue flowers smother the grey-green needled foliage. It’s happy in pots and creates unbeatable evergreen goat-proof hedging.
Russian sage: Fragrant spires of pale lilac from August to September make Perovskia a must-have drought-trooper in gravel, cottage and Mediterranean gardens.
Zebra grass: Adored by landscape designers, Miscanthus creates elegant focal points for larger gardens. Unparalleled, often zebra-striped foliage in dreamy cream and green are topped with buff to damson flourishes in summer. It’s fabulous for introducing texture, swaying height and structure to long or wide borders and you might try growing one of the evergreen varieties to create unusual garden divisions.
Thyme: Forget parsley! If it’s drought-busters you’re after, thyme is your go-to herb. Small pin cushions of aromatic delight are smothered with tiny tubular flowers from spring in shades of pink, red and white. Perfect in herb gardens, trailing over walls or charming left to its own devices lining paths or peeping from nooks and crannies.
Drought-resistant hedging and shrubs
Box: Buxus is an enduringly popular evergreen classic and copes surprisingly well with long bouts of dry weather. Planting box ball topiary or hedging adds formal charm to cottage gardens as well as formal courtyards and rambling country acres.
Beech: Whether you wish to grow beech as a hedge or ornamental tree, once established, its drought credentials are rock solid. Choose from fresh green or moody purple-leaved varieties and if you keep your hedge under 6ft, you’ll find the leaves stay on even through winter.
Buddleja: The joy of free-flowering butterfly bushes guarantees butterflies and buzzing bees all summer long and they can go for weeks without watering without too much trouble.
California lilacs: Ceanothus with vivid powder blue to deep blue blooms easily shrug off bouts of dry weather without compromising their flower displays. Did you realise that the abundant summer flowers are beautiful as well as practical? Pluck blossoms and massage them with water in your hands to make a natural detergent to clean grubby greenfingers.
Cherry laurel: Easily the most popular hedging for town and country, there’s no getting away from the sheer versatility of cherry laurel. Vibrant green, glossy foliage makes it an all-round winner and a drop of dry weather doesn’t bother it in the least.
Escallonia: Evergreen escallonia doesn’t mind a little water deprivation and.
has gorgeous flowers ranging from pink, red or white from June to October.
Holly: We tend to think of evergreen hollies as winter plants, but before they strut their flowers and berries in the autumn/winter landscape, they’ve still got to make it through long, hot summers and it’s something they manage admirably even when the weather heats up.
Lavender: Possibly the most popular aromatic shrub, lavender hail from the Mediterranean so are no strangers to water shortages. With so many different varieties to choose from, it’s a no-brainer to grow them.
Honeysuckle: We tend to think of climbers when we talk about honeysuckle, but shrubby golden honeysuckle (Lonicera nitida) often gets overlooked. It’s a dependable, neat evergreen shrub that makes great hedging and can cope with dry conditions admirably.
Oleaster: We used to call them Elaeagnus but whatever their name, they make regal garden shrubs with deep green, silver and gold-edged foliage, and they pack a perfumed autumn punch! Orange berries in spring make them a dependable choice in any drought-proof garden.
Portuguese laurel: Many gardeners, especially those trying to create a Mediterranean garden opt for the deep green polished leaves of Portuguese laurel with its candle spires of fragrant creamy flowers in spring. With impeccable drought credentials, it serves as a feature shrub or dwarf hedging and is a great choice for evergreen boundaries.
Drought resistant trees
Bay: The distinctive smell of sweet bay leaves and its sheer versatility, together with its ability to put up with dry spells make bay (Laurus nobilis), a sound investment for all gardens great and small. Use it for hedging, topiary or feature trees.
Yew: Possibly the gold standard of hedging, yew, (Taxus), is an elegant choice for topiary, hedging and garden divisions. For all its aristocratic bearing, it’s unfussy about dry weather and can take whatever the British climate throws at it.
Japanese Privet: A popular evergreen for hedging, it can also be grown as a standalone feature tree. If you’re looking for architectural inspiration, you can even buy pleached trees. Privet (Ligustrum japonica) copes with just about all soils, and it also withstands drought and absorbs pollution and carbon. It’s an eco-friendly choice, especially for coastal gardens.
Head to our blog to discover more gardening advice and planting inspiration.