It may seem odd that watering your garden could be a problem in the Manchester climate, after all, are we not the rainy city?
But no matter how much of it we have here, water is a finite resource. Water molecules go round and round in a cycle: evaporation, condensation, rain, run-off… repeat. Although technically there are some chemical reactions, such as from volcanic processes, which can create water, this new water output remains very marginal. What’s more the amount of fresh water (what we use for people, plants, car washing, gold fish bowls…etc) is limited, only 2.5% of all Earth water is fresh water, the rest is saline ocean water.
And while the water molecules keep doing their thing, our demand for fresh water has increased dramatically. There are more of us, doing things which require more water. In the UK, water consumption per person per day is currently around 140 litres, compared to likely consumption of around 50 to 60 litres 100 years ago.
We are also quite poor at dealing with rainwater by surrounding ourselves with impervious surfaces, which means that water runs off fast out of our gardens and down the drains.
So when looking at how you use water for plants in the garden, there are some basic elements worth bearing in mind. This is a quick what, where and when of watering.
What?
When watering in the garden, we think about watering plants, but actually, not all parts of the plants are efficient at taking up water. Most vascular plants (i.e. the ones with tissues which can carry water and nutrients, so that exclude mosses) will take up water by their roots, pretty much 90% of a plant water uptake. So what you really want to water are the roots of a plant, or even better, aim to create the conditions by which the plants roots can find water easily when they need it. And that means watering the soil the plants are in.
Do all plants need watering? Newly planted plants will definitely require some watering in dry periods, this is because their roots might have not developed enough to access soil moisture.
Large plants (such as trees or shrubs) in particular, will not have developed enough roots to sustain the size of their canopy, and will be more vulnerable than plants which have grown progressively from a seedling in a garden. Even drought tolerant plants, like Lavender, may not be able to deal with drought when first transplanted from a pot into the ground.
Mature trees and shrubs, which have been in the garden for a long time and are adapted to the soil conditions, should not need watering in a dry period, even though they may suffer a bit and lose some of their leaves to cope with exceptionally dry weather.
It’s different for herbaceous perennials and vegetable crops, which do not have the same extensive root systems, and may need some watering during drought time.
What about lawns? Unlike other plants, grasses grow from the base of the leaves. This is why cutting the top of the grass does not stop it from growing, the leaf blades naturally start lengthening again from the base. And so established lawns do not require watering to survive. The top growth may go brown or die, but the roots will usually go into dormancy during a hot period and will start pushing new growth once the rain is back. More information on watering lawn and how best to go about it from the RHS –
https://www.rhs.org.uk/lawns/drought-care
You may not have heard my rant about pot-bound Britain yet, but the main point is that plants in pots have the lowest chance of survival. Pots are hard work, and that includes having to water them much more in periods of drought. They can also end up flooded in very wet weather, which is equally bad for plants.
Hanging baskets are an even more extreme case of pot-bound madness, as they hang in the air, they dry even faster…like your washing on a line, as astutely noted by Bob Flowerdew.
Where?
Always water the soil at the base of a plant, so that water is directed at the roots below ground. You also want to give plants a good drench, so water can travel down in deeper soil, and encourage roots to develop that way too.
In some cases, you may want to install a partially buried spike or perforated tube to direct water at the base of a planting hole, and encourage the roots development. This can be particularly useful for newly planted trees or for pots / raised beds in greenhouses.
Sometimes the ground will be covered with low vegetation, such as new veg seedlings, in which case it may be difficult to direct the water onto the soil only. In which case it is best to have the watering can rose facing upwards, so that the water falling on the seedlings is a soft shower, as opposed to a forceful downpour.
When?
You should not have to water plants outside in Autumn and Winter, even if it’s dry. There should be enough moisture in the ground, and from end of Autumn, plants slide into dormancy, whereby their metabolism slows down and they have limited need for water.
With newly planted trees and shrubs, water infrequently but deeply. A good drench every so often is better than a little bit of water all the time. In dry periods, you may have to water every 2 to 3 days. This type of watering may be required for 2 to 3 years after planting.
Newly planted herbaceous perennials or vegetables seedlings are different. They may have to be watered every day.
Morning or evening? Overall most people, including mad dogs and Englishmen, have got the idea that it’s not good to water plants in the hot midday sun. This isn’t so much that water left on leaves could end up scorching plants, but more about the inefficiency of watering at the hottest time of the day, when water will be evaporating fast and not travel to the plant roots.
Then, there are different schools of thought about morning or evening. Cold water in the evening may attract slugs, or create conditions for the proliferation of fungal infections such as mildew.
In the morning water will start to evaporate fast due to the heat rising during the day, although it can be argued that the plants will be provided with water during the day when they are most likely under heat stress. So, you decide.
And finally, a word of caution, it is possible to over-water. If you are unsure about whether a plant might need watering or not, you need to check the soil, if it’s still moist a couple of inches below the surface, then it’s unlikely that the plants need watering.
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These are just a few guidelines. Join me on 14th March 2026, 2pm – 4pm at St Margaret’s Church behind Bud Garden Centre, to discuss in more details how best to deal with water in the garden: what can you do to soils to ensure they both retain and drain water appropriately, how to select plants, what type of water can be used and how to have gardens ready to deal with high rainfalls.
Book tickets for the Art of Watering workshop here.
