Green manures are crops that are grown in order to increase soil fertility
and prevent leaching of nutrients. They may also suppress weed growth. They
are particularly useful where the ground is not in good condition and needs
a boost to humus levels. Some can improve the level of trace elements in the
soil by drawing them from the subsoil by means of long taproots. Light sandy
soils in particular benefit from the ground covering action over the winter
months when bare soil would be prone to leaching by winter rains. Digging
in (or cutting and covering) wilted green manures stimulates the valuable
work of worms and micro -organisms in breaking down organic matter into a
form that plants can more easily absorb. The legumes (members of the pea family)
fix nitrogen.
|
Plant |
Deep rooting |
Weed suppressing |
Attracts beneficial insects |
Leguminous |
Months to sow |
Comments |
|
Alfafa |
Y |
|
|
Y |
(3 -9) |
Dig in green, drought / t |
|
Blue Lupin |
Y |
|
|
Y |
(3 -6) |
Dig b/f, light, acid s. |
|
Buckwheat |
|
|
Y |
|
(3 -8) |
Calcium. Poor, light s. |
|
Chicory |
Y |
|
|
|
(3 -9) |
Light s. |
|
Clover |
|
Y |
Y |
Y |
(3 -8) |
Sandy or loam s. |
|
Fenugreek |
|
Y |
|
Y |
(3 - 8) |
Rapid, between crops. |
|
Fodder Raddish |
Y |
|
|
|
(8) |
Over winter ‑ rots. |
|
Grazing Rye |
|
|
|
|
(8 -10) |
Over winter. |
|
Mustard |
|
|
|
|
(3 -9) |
V. fast. Reduces wireworm. |
|
Phacelia |
|
|
Y |
|
|
Dig b/f. |
|
Sunflower |
|
|
|
|
(3 +) |
Cut before woody.h |
|
Trefoil |
|
|
|
Y |
|
Cut young. Compost tops |
|
Winter Tares |
|
|
|
Y |
(3 - 10) |
Heavy non ‑ acid s. |
Key : H Humus rich B/f before flowering s soil.
Supplies can be obtained from good Organic Mail Order Companies.