CROP ROTATION
As daylight begins to lengthen and the sun’s warmth begins
to get noticed we look for some excuse to make a start to our gardening year.
We have had plenty time to look at catalogues and visit garden centres and
choose which crops to grow for 2017, so with seeds in hand and potatoes getting
chitted we can relax on an evening and plan where everything is going. We have
heard of crop rotation, but for some it is still a bit of a mystery.
Anna picks runner bean Enorma |
We do it to grow crops on fresh soil away from last year’s
crops that may have been infected by disease so hopefully we might just avoid
reinfection. The main fungal diseases to avoid include clubroot on brassicas,
white rot on onions and blackleg on potatoes. However other factors crop up as
some crops such as pumpkins, are gross feeders so need to go on land that was
heavily manured during the winter digging. Other crops such as parsnips,
carrots and turnips prefer fertile soil that got no compost in winter otherwise
you end up with forked roots. Salads like fertile soil so they can grow fast as
they are often used as a catch crop or an intercrop, (more later). Then of
course, different crops like varying degrees of acidity or alkalinity. Potatoes
prefer an acidic soil otherwise scab could be a problem. All the brassicas
prefer an alkaline soil with a high pH as this reflects their natural
Pumpkin just planted |
It is a good idea to draw up a plan of your garden to scale
and include paths, sheds and compost heap. You can then work out where crops
are to go well in advance of sowing.
My rotation plans show where last years potatoes were grown,
and this is where I start, as this area gets limed for the next crop of
cabbages, sprouts, Swedes, kale and cauliflower. The land that grew these
brassicas last year will now get the gross feeders such as peas, beans,
pumpkins, courgettes and sweet corn. Last years land that grew the gross
feeders will now become the root crop area plus salads. On a four year
Turnip Purple Top Milan |
If you grow strawberries on the same site and replace these
every three years bring this area into the rotation and replant fresh
strawberries as part of the rotation. They won’t be affected by clubroot or
white rot.
Intercrops
Salads are short term fast growing crops so are very
adaptable to use as an intercrop between other slower growing crops with wide
spaced rows such as Brussels sprouts or sweet corn, or even on the sides of
your celery trench before they need earthing up. Lettuce as pick and come
again, rocket, radish and baby beet can all be used as an intercrop to get the
maximum value off the land.
Salad catch crop |
Catch Crops
The same salads can also be used as catch crops where less
hardy vegetables such as courgettes, pumpkins and sweet corn don’t get planted
till early summer leaving the land free for a quick maturing catch crop from an
early sowing. Similarly catch crops can be used after an early harvested crop
such as early potatoes, onions or first early peas. There is usually time to
get in another crop before winter, and if you grow winter hardy lettuce, spring
onion and rocket they can continue to crop well into winter especially while
winters continue to be mild.
If you have enough salads any spare land can be sown with a
green manure crop in early spring and autumn to help improve the soil
fertility.
Tie in climbing
roses after pruning or any affected by recent gales, otherwise wind rock can
damage next year’s flowering stems.
END