Garden School:


Garden School:
Teaching this week: Roses (again!), and how to get them to flower lower down.

Monday, 9 July 2018

Hot weather Watering: Part 1, general principles,

This week, I have had everyone and his dog asking me about watering plants. Hardly surprising, as we've had hot sunshine, hot winds, and no rain for a good four weeks or more, and no sign of the hot weather breaking for at least another week or even longer.

"Phew, what a scorcher!" as they said, back in 76.

I feel sure that in a couple of weeks' time, we'll be shivering indoors, watching the rain on the windows, and wonder if we imagined four whole weeks with constant sunshine, no rain, and no end in sight....but in the meantime, what can we do to help our plants?

I wrote an article about this for GreenPlantSwap the other day, but I have a lot more to say on the subject, so I've split it up into four parts:

1: General Principles.
2: Don't waste water on plants that don't need it
3: Pots
4: Resuscitation

Right, let's start with general principles.

When the weather is hot and dry, you might need to water your plants, and in essence, that means splashing a bit of water on them from time to time.

But as always, there's a little more to it than just a simple bald statement, and as the phrase "hosepipe ban" seems to be hovering in the air, it's worth a few words to encourage us all to use our water wisely.

How to water.

When you water, don't splash it around wildly, all over the foliage, the path, your feet, etc: aim it around the base of the plant That's the bit that needs the water.

Turn down the pressure of the hose, or - better - use a watering can. You are not jet-washing the plants, you are imitating nature, which droppeth like the gentle rain from above.

If you find using watering cans too heavy, and you really have to use a hose, then buy one of those big nozzles with a variety of water patterns, rather than the sort which make a narrow jet.

This is the jet-wash type of nozzle - you twist the yellow part against the grey part to make the spray narrower (and into a jet-washer) or wider (and softer).

There is no pressure control or trigger, it's either on or off: the only way to turn it off is to twist it all the way wider and wider until eventually it stops.

After spraying your legs, and everything within a 180 degree angle...
This type - right - is much better in three important ways.

Firstly, see that big roundy thing at the left? It's a series of spray patterns, you twist it round to select them. The best one is the "gentle rain" setting.

Secondly, see the grey/yellow trigger? That means you point it in the right direction, squeeze the trigger and there is the water, exactly where you want it.

You don't waste water on the journey between one watering point, and another.

The red band going horizontally across is a lock for the trigger, so if you have a large area to water, you can lock the trigger on, to avoid hand strain. Nice!

Thirdly, and best of all, see that red sticky-up tab on top? Push it to the right, you get full pressure. Push it to the left, it reduces the pressure.

So, even if you've turned the tap on too far, you can reduce the pressure down to a point where you are gently watering, not sand-blasting.

Now, a word about those mains taps: don't turn them on full! You don't need to turn the tap on and on and on, until it won't go any further. When I use my own mains tap at home, I turn it from the 12 o'clock position to the 9 o'clock: that's one quarter turn. That's all. And that's plenty of pressure.

Turning the tap on full just puts pressure on every connection in the hosepipe, and much of the time, it means your tap end is dribbling and wasting water. So don't turn it on so far!

Next: how much to water.

Don't pour on so much water that it starts to run away, or makes a big wet puddle on the surface: both of these mean that you have put too much water on too quickly, without giving it time to soak in.

This also means, counter-intuitively, that you have stopped too soon!

Your aim is to give sufficient water that it can soak into the ground around the plant. This means a slower application speed - see above - and it can mean going round the plants in a circuit: instead of doing each plant once and that's it, go to and fro from plant to plant, giving the water time to seep down into the soil before returning.

To explain what I mean, this morning, I watered a long bed of roses for a Client: if you imagine each rose bush has a number, I started at number one, and gave it a slowish count of five. Then on to number two ("..two, three, four, five")

This gives the water time to soak in to number one.

Back to number one (second sloosh), then number two (second sloosh) then on to number three (first sloosh... two, three four, five.)

Back to number one (third sloosh) and now we're up and running: on to number two (third sloosh, two three, four, five) , then number three (second sloosh) then on to number four (first sloosh.)

Back one: number three (third sloosh), number four (second sloosh) and on to number five (first sloosh)

Back one: number four (third sloosh, number five (second sloosh) and on to number 6 (first sloosh)

Hmm, it sounds a lot more complicated than it is!

Basically, once you get going, you water three plants as a group, one, two three: then back one and water three, including a new, dry one, each time. This gives each plant three bouts of watering, with time between for the water to soak in.

A simpler method, on small gardens, is to go from one end to the other, then back again, and back again. (Some of my gardens are quite large, so I've had to establish the most efficient way to do things.)

If you put on too much water at once, you'll often see it forming rivulets and running away. This is a sign that you are watering too fast: water will always take the easiest course - lazy stuff! - and it would rather run away on top, than soak in. This is a particular problem on banks, or beds which have a slope to them.

The answer is to do it more slooooowwllllyyyyyyyy.

You can also build little mini-moats around selected plants, to give the water time to soak in. Of course, they are anti-moats, really: just a ridge of soil, built up on the downward side of the plant, to stop the water galloping off downhill. Technically they are bunds (how many of you know what a bund is? Answers below, please...).

Sprinklers:

Don't slap on the sprinkler.

Sprinklers are the work of the devil for anything other than lawns, as they waste water by spraying it indiscriminately all over the place, they splatter water all over the foliage, leading to those white water-marks and spots which make people think their plants have a nasty disease, and - worst of all - people tend to set them going and then leave them for an hour or more. Such a waste! Our precious, clean, expensive tap water!

Also, if you use a sprinkler rather than a can or a hose, you miss the opportunity to have a chat, as it were, with all the plants. You miss out on seeing what they are doing, how they are getting on: which ones are flowering, which ones need deadheading, which part of the bed is starting to need weeding, where the gaps are.. all those things that make gardening more interesting.

Watering cans:

The best way - not only are you directing water exactly where it's needed, at a nice slow speed, but it gives you a chance to check out all the plants, as you go along. But I do accept that it can be heavy, and can be slow if you have a lot of plants to water.

You can make things faster and easier by having a dipping tank: this can be nothing more complicated than a large open-topped tub under the tap of the water butt, sufficiently large for you to dip the watering can in. When you are watering, you leave the tap open enough to top it up as you use it.

This cuts out all that tedious standing-around-waiting-for-it-to-fill.

Or, you can get two watering cans and learn to judge how far to turn the water butt tap on, to get the second can full just as  you have finished using the first one.

Handy Hint: (known these days as a Hack, apparently, but I'm that old that I remember when Life Hacks were called Handy Hints, or possible Top Tips) many water butt taps don't put out a neat flow at anything other than fully open, so cut a short length of hose and push it over the tap.

Here's one I made earlier... you might need to hold the end in a  beaker of hot water for 10-15 seconds to soften it, but it's worth it to avoid it splattering all over your hands.

When to water:

There's an urban myth that says it's a waste of time to water in the middle of the day or when it's very hot.

Not true! Well, not entirely true.

The best time to water is very early in the morning, while it is still cool: the water will soak down into the soil straight away, and will be available to the plants as they start their day's work.

Watering last thing is the evening means you are putting water around the roots of the plants while they are "asleep", so they are not benefiting from it: and you are creating a whole mass of five-star hotels for slugs and snails, allowing them to move freely all around your plants overnight, which is their busy period. So watering in the early evening is actually the worst time to water.

Watering in the middle of the day means that the water goes straight where it is needed, and is appreciated straight away. Yes, some of it will be lost to evaporation, but even on the hottest day, most of the water goes where it is needed, and you will see that the soil remains damp on top for some time. If you really, really believe that the sun will suck all the water out of the soil, then after watering, use the hoe to rake some dry, dusty soil over the watered areas, to act as insulation.

As a general rule, then, watering in the morning is best, evening is less good,  but it's far, far better to water in the heat of the day, than to not water at all.

Coming tomorrow:

Part 2: Don't waste water on plants that don't need it
Part 3: Pots
Part 4: Resuscitation

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