'Green manure' seeds available now
Winter Tares, Field Beans, Winter Grazing Rye, Phacelia
This year, we are stocking four green manure seeds: Winter Tares (Vicia
sativa), Winter Grazing Rye (Secale cereale), Field Beans (Phaesolus spp) and
Phacelia. All grow well on heavy soils, add nutrients to the soil, and their
roots improve soil structure.
Although you can sow Tares, Rye and Field Beans in Spring, their real value on
allotments, where we tend not to want to tie up ground during the main growing
season, is that they are hardy, and able to be sown as other crops are
harvested in late Summer or Autumn. They then grow over Autumn and winter - and
can be dug in in Spring.
Tares and Field Beans are nitrogen fixing, and take up and hold other
nutrients as well, preventing them from being washed away. Both
over-winter. Tares and Field Beans may be planted to the end of October
in the London area, though do better if planted in September. The aim is
for these crops to produce good top growth to dig in by Spring. Field
Beans are said to be able to be planted as late as November, but my
experience (Bob H) is that germination and growth can be poor if sown that late
in the year. so the
crop won't fulfil either its purpose of retaining nutrients over Winter,
nor of adding much bulk to the soil by Spring.
Rye has a dense root system, amd is an efficient 'taker-up' and holder of soil
nutrients, but does not fix nitrogen. Its roots penetrate surprisingly deeply
into even heavy clay, and
will
help improve soil structure. It is one of the hardiest crops, growing at any
temperature above freezing. It may be planted to the end of November in
the London area, but, as with Tares and Field Beans, planting in September
means there will be more bulk to take up hold nutrients over Winter, and to dig
in
in Spring.
Any of of these three 'green manure' crops may be planted on their own, but
Vetch and Rye may also be planted together, and will complement each other, so
that nutrient harvesting is more efficient.
By bulk purchasing, we are able to offer Winter Tares, Field Beans and Grazing
Rye at around £1.50 per pound - which is a fraction (half or even a
third) of
the common retail price!
The experience of our members is that these seeds keep well if you don't use
them all
at once (store dry and cool).
Phacelia is another effective and attractive green manure. We packet it in 15
grams for 40 pence, a lot less than the green manures above, but the Phacelia
seed goes a long way! It is very fast growing
- germinating within just a few days in warm conditions, and reaching 6 inches
high in 3 weeks. Phacelia produces a dense mass of leaves that will quickly
reach 30 - 45 cms (up
to 1.5 feet), smothering weeds, and attracting bees when it flowers. These
characteristics mean it is particularly good for planting at any time from
Spring through to late Summer. Phacelia is
is quite hardy and may over-winter. It can be dug in at any time, but if the
crop has flowered, it is advisable to dig it in before it sets seed.
Photo and more information on Phacelia here
.
All green manure seeds are available now from the Trading Shed.
How to use Green Manure Seed
Sow Vetch and Rye in autumn by broadcasting or in closely-spaced rows, raking
into the soil
surface to a depth of 1 - 2 cm. Field Beans should be planted 3 - 5 cm deep, 10
cm apart.
It can help to soak Tares or Field Beans in water for up to 24 hours before
sowing
(best soaked in a flat tray so that the seeds don't suffocate from lack of air,
and don't leave for much longer than a day). Dig in the crop in Spring.
Tares can be sown in Autumn from late Summer till end-Oct, and from early
Spring to early Summer. Winter Grazing Rye can be sown from late Summer to
late-October. You will get the best results from sowing earlier than later in
these
suggested time-frames.
If you sow in Spring, you should dig in before the Tares sets seed in Summer.
Grazing Rye will grow to 5 feet high if left into Summer, and looks rather
beautiful, but by then, will have become tough and difficult to dig in, and
slow to rot in the soil.
Sow Vetch and Rye at 20 grams per square metre. Half a kilo of Vetch or Rye is
enough for 20-25 square metres which is about a
fifth of a 5-pole plot.
