Alfalfa Green Manure
Alfalfa is a hardy perennial which can be grown for either for 2 to 3 months or a year and has excellent nitrogen fixing properties making it one of the very best green manures to use in the garden.
Alfalfa takes nitrogen from the air and holds it as nodules on its roots, a process called “nitrogen fixing”. This nitrogen becomes available in the soil for other plants to use when the alfalfa plant is cut down and its roots are left in the soil, or when the plant is turned into the soil.
The long deep roots of the Alfalfa also improve the structure of the soil by breaking up soil pans. Alfalfa roots reach down into the sub-soil, bringing valuable hard-to-reach nutrients up to the soil surface where they are stored in the leaves of the plant. Using the cut alfalfa in your garden and compost adds these nutrients to the upper layers of your soil where other garden plants can use them. Alfalfa is particularly good at bringing iron to the surface, a micro-nutrient needed for chlorophyll synthesis.
|When to sow||March through to September for over-wintering|
|Where to sow||Avoid acid or wet soils, likes dry soil best.|
|Soil preparation||Remove weeds, digging over if it hasn't been recently cultivated and rake level.|
|How to sow||Scatter seeds over the surface of the soil ensuring an even coverage.
Make sure the seed is in firm contact with the soil by gently tapping over the surface with the back of a spade.
Water in well.
|Growing Period||2-3 months or up to 1 year for overwintering.|
|Care||Cut down before flowering when the stems are nice and soft as they decompose quicker, retain more beneficial nutrients and are easier to incorporate into the soil.
If grown long term, cut down 2-3 times a year to encourage new growth, the cuttings can be composted or left on soil surface as a mulch.
Leave the plant material to decompose in the soil for at least 4 - 5 weeks before growing any vegetables in the soil. This allows the plant material to break down into rich organic matter, allowing nutrients to be released slowly over a period of time.
|Coverage||50gm covers 20 square metres ( 2.5gm per meter square)|