Agriculture Reference
In-Depth Information
Preparation
All French beans prefer a rich soil with good moisture-retentive properties, and
are deep-rooting. Check your soil condition by digging a test hole, about a spade-
and-a-half deep, and if necessary amend it by forking in some compost and
watering it in. Ideally this should be done around the same time as the seed is
sown in modules, to give the soil time to settle again.
Sowing
Do not be tempted to pre-soak beans before planting, as this encourages halo
blight, to which they are prone. To minimise losses, sow individually in deep
modules or biodegradable pots in an area protected from mice, with a little heat
if early. Once the leaves appear, transfer to a slug-free shelf, transplanting when
large enough at a spacing of 35cm each way. French beans will not tolerate even
one degree of frost, so fleece the seedlings unless you are confident that all danger
of frost has passed; if they are frost-damaged they will never fully recover and
your only option will be to re-sow. Sow from late April; for a continuous crop
successive sowings can be done every month or so and dovetailed with those
grown outside.
If you wish to sow direct, place the seed in 5cm-deep drills 35cm apart, sowing
several extra seeds at intervals between the rows for filling in any spaces.
Remember that if you are growing more than two rows you will need to leave
space between each pair to give you access for harvesting.
Growing
Although dwarf French beans usually do not need supporting, they can grow
quite tall in the protected environment of the tunnel, and the sheer weight of the
developing pods may drag them down. If the plants begin to look unstable, place
a bamboo cane at each end of the row and run some twine in a loop between
them and around the plants.
Some additional watering will help the plants establish themselves after trans-
planting, and yields will be higher if they are kept nicely moist once flowering
starts. However, avoid wetting the leaves (as far as possible) to discourage the
spread of diseases such as halo blight.
Harvesting and storage
For the best yields and flavour, harvest regularly while the pods are still young.
As with most beans, any seed reaching maturity releases a hormone to stop further
flowering, so make sure not to miss any. Varieties with coloured pods can help
here as they are easier to see. After about four weeks of harvesting the beans get
fewer and coarser and it's time to take the plants out. However, if you need to
extend the harvest a little, a single boost with double-strength liquid tomato
fertiliser can sometimes trigger another show of flowers.
