Blue Lupin Green Manure
Blue Lupin is a deep rooting green manure which provides excellent nitrogen fixation. A hardy annual green manure that can be planted from March to July and one that is a vigorous grower, that produces a mass of green matter.
Lupin 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 lupin 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 lupin also improve the structure of the soil by breaking up soil pans. Lupin 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 lupin in your garden and compost adds these nutrients to the upper layers of your soil where other garden plants can use them.
Lupins seeds should be sown 8cm apart, therefore they are not as good as other green manures as a weed suppressant. They can be be slower to germinate than other green manures.
|When to sow||March to July|
|Where to sow||Suitable for most soil types especially light acidic soils.|
|Soil preparation||Remove weeds, digging over if it hasn't been recently cultivated and rake level.|
|How to sow||Sow 2cms deep and 8cms apart in drills that are 15cms apart
Water in well.
|Growing Period||2-4 months|
|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.
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 8 square metres (6.25gm per meter square)|