Agriculture Reference
In-Depth Information
deficient in one or more minerals. If you see signs of unhealthy growth, particu-
larly in 'indicator' plants such as tomatoes and cauliflowers, check the mineral
deficiency list in Chapter 11, and take action if necessary.
Finally, if you dig your beds and then find that you can't get the cover on promptly,
cover them with cardboard or black plastic and keep it wet or weighted down
with stones. Seeds of pioneering species such as nettles and dandelions will find
any bare soil very quickly, even in winter, and the last thing you want is for some
of these weeds to get a toehold before the cover is even on.
Start sowing
There is no need to wait until your tunnel is up to get a start on the season, and
indeed you will be using a warm windowsill or propagator every year to do
exactly that. Once you have planned your tunnel for the first year (see Chapter 1,
page 15), go ahead and get the first sowings started in small pots or module trays
that will fit easily on south-facing windowsills or, if it's warm enough, in a cold
frame or two. That way, once your tunnel is up, turning it into a productive space
will be much faster and easier.
How early you can do this really depends on what kind of conditions you can provide.
The warmth and light you can give the seeds determines how fast they will germi-
nate and grow, while conditions in the tunnel determine how soon they might be
moved to your staging. If you started seeds indoors and they are becoming big
enough to need potting on but the tunnel is not ready, transfer them to a cold
frame so long as it's not too cold outside. This will slow their growth and give them
time to acclimatise to a cooler environment. If you don't have a cold frame, it is
easy and inexpensive to build one. Alternatively, commercially available cloches
will work in a similar way. The important thing in both cases is to make sure that
pests can't get in to eat the young plants. They will probably be the tastiest thing
for miles, so you can expect them to be the focus of lots of unwanted attention.
The golden rule with seedlings is this: give them what they want. If you stunt
their growth, or they get too leggy from light deprivation, they may never fully
recover - so try to be realistic about what you can achieve. Even though it's
tempting to plant tomatoes in January, few of us can really give them the support
they need until the tunnel is ready to receive them in April. If disaster strikes, or
you simply can't bring on the seedlings you need until the tunnel is already in
place, then buy plants from a local nursery rather than starting late. With the
polytunnel, everything is about timing.
Once your tunnel is up, you're ready to go. A polytunnel in spring is basically one
huge cold frame. It's protected from the wind and heavy rain, the earth inside is
warmer than in the beds outside, and it will get more light than any windowsill
in the house. Once light levels pick up in mid-spring, it's an ideal place for seedlings
