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Watering FAQ

This FAQ was originally published on www.nugget.demon.co.uk.
Can anyone give me advice on how to apply mulches around:
i) shrubs
ii) vegetables
iii) herbaceous plants?
To concentrate water where I want it I build walls of soil around all of these types of plants so they are sitting in the middle of a saucer shape. Do you think if I gave them a good soaking now and then mulched over they would survive the summer or is it too optimistic? Do you put the mulch right up to the stem or leave a gap? If you water again later do you have to remove the mulch first so the water can get to the plant more efficiently? If you mulch each year don‘t you ultimately end up with a raised bed?
We have a hose pipe ban in this area and I have a large garden to water. I find that carrying watering cans every day plays havoc with my back so I am anxious to minimise my labours if possible. Trish.

I shall not answer your question :-)
My garden is in nearly the driest (and, in summer, hottest) part of England, and is basically sand on clayey gravel. There is no humus below about a foot down, and wasn‘t below about 6” when I moved in! So here are my comments on how to garden without watering:
1) Choose appropriate plants. Forget spinach except in spring and autumn, and don‘t bother planting for succession - if vegetables aren‘t established by the time the drought is, they won‘t live. But do plant for succession (especially carrots, spinach etc.) in September, because you may get a warm autumn.
2) Decorative plants are easy - go for Californian, Mediterranean, South African, etc., ones, plant them in early spring or autumn, and forget about them once they are established. Sand and gravel are good because they don‘t waterlog, and the plants don‘t have to re-establish their deep roots.
3) Water deeply and rarely around the plants while they are getting established - and similarly for vegetables. If they need water once they should be cropping, write them off and try again next year.
4) Get as much humus into the soil as you can, but mulch only shallow-rooted plants (which you should have avoided). After all, the bone-dry top 2” of soil is a fairly effective mulch! I.e. encourage them to get their roots DOWN and not footle around near the surface, where it bakes.
But your experience may differ ....
Nick Maclaren, Email: nmm1@cam.ac.uk

You have my sympathies. Mulch right up to the stem. Water if you see early signs of distress. Do not remove the mulch to water. Add mulch each year *only* if you see that the previous year‘s has rotted away - the bed will not rise all that much, if at all.
When you think a plant (or plants) need water (drooping, scorched edges to leaves) water it very thoroughly so the water goes very deep. If you water like this infrequently the plant will develop deeper roots and escape the worst of the drought.
Nick‘s points are very valid (another post: plant for drought, etc.) but one thing that might be borne in mind: the idea of a mulch is to break the capillary action of fine-grained soil from drawing up moisture from below and evaporating it. Therefore, the best mulches in this respect (some mulches are for nutrients and weed suppression) are large particulate matter.
Gravel is ideal. Broken bark would be fine. Cocoa shell is good. Anything that is too fine or breaks down will be less good. I‘m not so sure that grass cuttings would be good, but they can work if they form an aerated mat of some thickness. Old carpets will do.... None of these suggestions is particularly cheap or convenient, unless you just happen to have access... A layer of newspaper could also work, but may look unsightly. But whatever you use, it will not help much if it forms a compacted mass in *close* contact with the soil and is itself absorbent (so it‘s back to large particulate matter).
(We still need to keep up the political pressure to ensure a rational water grid is constructed in this country! #$@$$! We need to plan for drier summers. It is INSANE that some areas of this country suffer water restrictions from one decade to the next ad infinitum... We are not prepared to live with regional food restrictions, or regional fuel restrictions, or regional power restrictions, etc., etc., etc.... so why put up with regional water restrictions?)
Keith Dancey

One tip I've used successfully is to bury a large plastic bottle a little way from the establishing plant having first punched a number of small holes in it. Leave the top just protruding from the soil (cover with a stone if it's too unsightly). Watering into this gets the water under the plant rather than spread over the surface (and evaporating). Choose a fairly rigid bottle as the soil around it will try to collapse it.
Kevin Rolph, Cambridge, UK

I have 3/4 acre of garden mainly laid down to an orchard of fruit and nut trees, but also have vegetable, soft fruit and ornamental areas. By extensive use of a straw mulch the only watering I do is:
1) To vegetables at crucial times of establishment and harvest
2) To herbs and flowers in pots by the kitchen door.
I top up the straw mulch each spring after the ground has warmed up but before it gets too dry. Mulch also has important benefits of weed control, and adding organic matter, but because of insulating effects it can slow the warming of the soil in spring, and lower the surface air temperature on frosty nights.
For trees and shrubs you should avoid the mulch touching the trunk as it could cause rot. It isn‘t a problem for annuals such as vegetables. I raise my vegetables in modules and plant them out into the mulch when they are a reasonable size, although large seeds such as broad beans can be planted directly under the mulch.
Eventually it will raise the soil level but it is amazing how it disappears over the year as it rots down. If there are weeds/grass on the area to be mulched a layer of newspaper under the mulch is recommended, and if there are weeds/grass adjacent to the mulched it is best to protect the boundary, e.g. with strips of old carpet, which can be covered with something more ornamental. I buy the straw each August whilst it is in surplus and leave it to stand. You need to avoid straw on which straw shortener has been used as residues can affect plants. For more ornamental areas bark chips can be used, but is too expensive to use on a large scale.
This year I have arranged for the grey water from the house to be pumped onto the soft fruit and a few choice fruit trees.
Nick Reeves

Keith Dancey writes:
> Nick‘s points are very valid (another post: plant for drought, etc.) but one thing
> that might be borne in mind: the idea of a mulch is to break the capillary
> action of fine-grained soil from drawing up moisture from below and evaporating it.
Yes, quite. I should have mentioned that, if you use soil/sand as a mulch, it MUST be extremely loose (which is much easier to arrange with sand than with clay)! Sorry about that omission :-( This is the main reason that crops are hoed regularly in very hot countries. Gravel or even medium-sized stones have the other advantage that they 'collect' the dew, which is why the traditional method of planting trees in the desert and semi-desert is with a mulch of stones.
Nick Maclaren, Email: nmm1@cam.ac.uk

I received a leaflet through the post today, called ”the water friendly garden”, published by the RHS and the Water Services Association. It contains lots of good advice about reducing the need for water in a garden.
But among the "wise watering tips" there was one gem which amused me. I share it with you:
”Move all pot plants and hanging baskets to the north side of the house or into the shade. Group them together to conserve moisture and water throughly early in the day and again in the evening.” Well, yes, I daresay that would conserve water. But to me it seems a bit like defeating burglars by moving all furniture and ornaments in the house into a locked cellar! So I think I‘ll give that tip a miss and keep my plants in the places I want them.
Happy watering!
Martin Hadfield, Ealing

Given that my soil is very free draining and last year was so dry, this year I added plenty of compost to the soil and lots of mulch on top. Everything was planted closer together than recommended to conserve moisture.
At regular intervals I‘ve half buried inverted 2 litre pop bottles with the bottom cut off to allow watering directly into the soil. I can therefore water the garden at any time of day without losing water due to evaporation or worrying about damaging the leaves. The main aim of getting the water into the soil is that it is directed to the roots where it counts and encourages deep root growth away from the dry surface. This way I don‘t need to resort to a hose as a watering can is sufficient, if a little invigorating!
BTW there was a company selling 400 gallon water butts at the NEC Gardeners World Exhibition for about 85 UKP. It seems viable to bury such a thing in the garden to collect rain water (assuming there is any), attach a pump to allow the use of a hose or sprinkler system and thus save on the water bill especially if you‘re charged on a water meter.
Anyway, so far all in the garden is wonderful :) What do others do to conserve water?
Steen Jensen - * Never uses his PC for games, honest * Watford, Herts, U.K.

There is a firm at Barnsley that sell old containers from soft drink manufacturers for about 35 UKP. I‘m not sure of the capacity however, or the current price.
After toying with the idea of providing a separate drainage system for grey and rainwater, I went to the grand opening of the local Wickes and came away with two 40 gallon water butts for 15 UKP each. After installing them below each downpipe, I realised that I could replace the tap with a fitting to take Alkathene, and run a pipe round to the cold water tank in my kitchen garden.
That only leaves the grey water to deal with.....
I‘m also considering asking the ice-cream factory next door if I can intercept the run-off from their roof. They must get a good few gallons when it rains.
Personal email: Jon@timewarp.demon.co.uk

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