Agriculture Reference
In-Depth Information
Feeding polytunnel beds
Every bed in the polytunnel should be given a dressing of at least 7cm of good
compost or about half as much well-rotted manure once a year, preferably in April
or May, and light soils will gain additional benefit from a smaller application of
compost in October or November. Use additional fertilisers only as needed for
hungrier plants, but keep an eye on the general condition of the soil using a soil-
testing kit once every few years. Apply dressings to the soil surface or fork them in
lightly rather than digging, because deep digging disturbs the soil structure.
Worms will take care of the rest for you.
Watering deeply rather than 'little and often' encourages plants to develop strong
root systems that will resist temporary dryness, and a soaker hose is an effective
way to deliver a lot of water with little effort. However, don't rely on a soaker hose
as a complete irrigation solution. Instead, think of it as providing background
watering; thirstier plants will still need hand watering, and all the soil needs some
top watering to encourage worms to take top dressings down into the soil, and to
stop the top layers of soil from turning to dust.
Manure
Animal manure is a traditional way of adding nutrients and organic material to
soil. It must always be allowed to rot under cover for several years before use,
and although this doesn't kill all weed seeds, it's much easier than making a
compost heap. You simply pile up the manure, put a tarpaulin over it, and leave
it to rot down. Garden centres charge quite a lot of money for professionally com-
posted manures, while stables are usually happy for you to take manure away for
nothing. Lighter manures such as really well-rotted horse manure are low
enough in nitrogen to use every year, and this makes for a really rich soil that
most plants love.
Fresh manure should never be used on any vegetable bed as it is extremely high in
soluble nitrogen and ammonia, and can kill plant tissue very quickly. Moreover, it
is full of potentially dangerous organisms, and even well-rotted manure should not
be used anywhere near plants that will be eaten raw. Disregard this advice at your
peril, or you could find yourself suffering from (at best) a squiffy tummy for a day
or so, or (at worst) a dose of salmonella. It's worth remembering that even if you
do decide to take the risk, it doesn't really matter how much care you put into
placing manure around salad plants, as you are very likely to splash some of
around it when watering - and quite probably some will land on your lettuce.
Many gardening topics specifically recommend using manure, but this is purely
because if you can get it directly from a horse owner or a farmer, it is essentially
free; there are no other real advantages over compost. Wherever you get your
