When people start off with gardening, they almost always do the same thing: once it has been sunny for a month and things are starting to look a bit sad, they break out the hosepipe or watering can every evening in the summer and spend half an hour giving everything a bit of a sprinkle. It’s absolutely the worst thing you can do for a plant in dry conditions, because what happens is, you wet the top inch (or few inches) of soil. Over time, the plant puts out roots into the bit of soil that has water – ie, the very top few inches. And during a hot day, that soil dries out. Completely. If you forget to water your plants for a day or two, they’ve now got all their roots sitting in the very bit of soil that is going to go bone dry on the first sunny day.
A plant sitting with nice, damp roots at eight in the morning, and bone dry roots in the afternoon, day after day, will begin to suffer debilitating stress. It will fall prey to pests, moulds (ironically, this includes mildew), and may, in its dying days, throw out a few desperate flowers in an attempt to at least have some seeds survive. But from the first half-hearted sprinkle to its final crispy end while you’re away for a week in Cornwall, that plant will have been dying.
If a plant roots down rather than out, it is more likely to encounter soil which is naturally moist. The roots will be protected from the stressful wet-then-dry daily rhythm of surface soil. And you’ll get plants that are better equipped to withstand drought through the summer. In order to achieve this you have to get the water down deep in the soil, and that means deep soaking it rather than giving it a ten minute wave-over with a hosepipe. If you deep-soak a bed, you will have the additional benefit that any rain that does fall will soak into the (already damp) soil, rather than simply running or evaporating off.
There are other, more subtle benefits to deep-soaking a bed once a week: keep your garden damp and you keep the worms active. This means your soil is being worked from below, which will improve that soil’s aeration and texture significantly – that makes it a friendly environment for plant roots. A damp garden is also a great environment for insects, birds, bats and amphibians. These creatures are essential components of a flourishing garden and will help you by pollinating plants, eating pests, and providing that element of pure delight, as you turn over a rock and find a little brown newt peering up at you. (Put the rock back, if this happens.)
The aim of watering is not to prop up a plant that’s already gone floppy and a bit crisp. The aim of watering is to encourage your plants to root down, as deeply as possible.
Watering is a strategy, not a solution, and it should be approached in preparation for dry conditions, not as a reaction to them.
I live in an area where a hosepipe ban is already effective. Any watering I do this year will be by hand and watering-can. I will also save and use bathwater – although I will be careful not to use it in isolation. It’s perfectly alright to use bath or shower water on flowering beds, and a little soap in the water will even act as a mild fertiliser. I wouldn’t use water from a washing machine, dishwasher, or from washing-up. The washing machine and dishwasher water will contain chemical surfactants (stuff that breaks down water’s natural surface tension), which won’t bother your plants, but if you have amphibians in your garden – and I hope you do, as amphibians do nothing but good in a garden, and desperately need our help – this stuff is really bad for them. Washing-up water is obviously going to be full of food and fat particles and those will rot, so avoid that as well.
I wouldn’t use “grey water” on vegetables. Really, who wants to eat a lettuce that’s been regularly splashed with Aunt Maud’s old bathwater?
In the back garden, much of my planting went in last autumn. I was relying on a winter soak to help it get established, but of course we haven’t had one, so my new plants need support this year to get going. My hope is that in April the rain will keep falling – but if it doesn’t, I have divided up my garden (in my head, obv), and will water one sixth of it by hand with a watering can each day (and on the seventh day, she rested). I have a pretty small garden, so this isn’t a terrible chore. I won’t bother with the lawn – it might look frightful by midsummer, but it won’t die, and frankly it has so much lovely clover in it that it stays emerald whatever the weather.
If your garden is full of large, established plants and shrubs that have been there for years, they will be fine without your help. Deep-rooted plants like roses or most bushes are well equipped for periods of dry weather. But anything that has been planted since last summer, or plants with very soft, green foliage (clematis, oriental poppies etc), is something you should be thinking about setting up a watering plan for.
Here are my top watering tips:
– Water the plants you need to water – anything tender and green, or younger than 6mo. Don’t water large shrubs or trees, and if there’s a hosepipe ban in your area, don’t bother to water your lawn.
– Get a calendar and when it does rain – and I don’t mean just for an hour, which doesn’t count, but for a whole day – mark that on the calendar so you have a good idea of when the plants last had a decent soak. You won’t need to bother watering for a few days after a full day of rain.
– Check the soil in your beds. If the top inch is dry, but below that it’s dark and moist, that’s fine. If it’s drier than that, soak it.
– Keep an eye on the weather, and when you’re due to have a run of several sunny days, water in preparation for it, not once it is happening. Water evaporates from warm soil fast on sunny days. Additionally, plants suck up and then “breathe” water vapour out in a process known as transpiration. If the water isn’t already there for them to use, they’ll start going into drought mode and bang go your flowers (and the plants’ disease resistance).
– Water either very early in the morning or late in the evening – preferably the evening. Never water during a sunny day, as droplets of water will act like lenses on the plants’ leaves and scorch them. You’ll also lose an awful lot of that water to evaporation.
– When watering a dried-out bed with a can, I always water it so it puddles, then leave it ten minutes for the water to start to sink down and “open” the soil, and come back and water it until it puddles again. Then once more. This gets water deep into the soil. If a bed has really dried out, I will do this for three days running.
– Water the plants that need watering once a week. Not every day. Give them a thorough, deep drenching once a week, and you won’t have to bother with them. Do it half-heartedly, and you’ll be out there every evening for very little result.
– Lastly, if you’re leaving your garden in someone’s care while you’re on holiday, take the time to explain to them how to water. Non-gardeners are lethal. You wouldn’t leave someone who had no idea about cats in charge of feeding your cat without instruction, would you? Well, you’ve probably put a great deal more hard labour and a great deal more money into your garden than you have your cat. It is a thriving ecosystem with thousands of inhabitants – it deserves to be taken care of!