Raise Your Own Plants for Green Manure Crops

Backgrounder

Annual plants for green manure crops are easy to grow from seed.  But propagating perennials (trees and shrubs that live for many years) from seed can be slow.

A faster way to propagate some perennials is to use stem cuttings‑‑that is, pieces of branches cut from mature plants or trees.  You can plant them in a bed or in individual plastic bags or cans to grow roots.  Once they have rooted, the cuttings can be planted wherever you want them to grow.

Dr. Nalini Dhawan of Bangalore, India teaches courses on plant propagation to women in her city.  She says that planting cuttings is one of the easiest ways of making a lot of new plants.  Some perennials, for example, gliricidia (Gliricidia sepium) or erythrina (Erythrina indica) root very readily.

“Of course, not all perennials will grow from cuttings,” she warns.  For example, Leucaena  or Cassia are better grown from seed.  But the cutting method is so simple that you can easily try it out on the perennials you want to propagate.

First, find a shady spot where the cuttings can remain undisturbed for 4 to 6 weeks.  It should be close to a water source.  And you should be able to reach it easily so that you can water and care for the cuttings.

You will need a clean, sharp knife with which to cut branches.  You will also need containers in which to root the cuttings.  Small plastic bags, about 10 centimetres wide and 15 to 20 centimetres deep, are the easiest to use.  You can plant 3 or 4 cuttings in each bag.  If you cannot get plastic bags, you can use flat wooden boxes, 15 to 25 centimetres deep, or large, shallow clay pots, or cans, 15 to 25 centimetres deep.  The containers should have a few small holes in the bottom so that excess water will drain out when you water the cuttings. If containers are hard to find, you can also plant cuttings in raised beds, about 15 to 25 centimetres deep.

Finally, you will need material to fill the containers.  Clean river sand is excellent material in which to root cuttings.  For hard or woody stems, mix some leaf mould with the sand to hold the cuttings firmly.  If you use soil, make sure it is clean and free of insects that will eat the cuttings.

Make the cuttings: The best time to take cuttings is just before the mother trees start their new growth for the season.  In tropical climates, this is usually just before the rains begin.

Choose healthy trees from which to take cuttings.  With a clean, sharp knife, cut off a few branches about 1 to 2 centimetres thick.  Cut each branch into pieces that are about 4 to 6 nodes in length.  The bottom cut should be just below a node and the top cut should be just above a node.  Cut off the leaves to keep the cuttings from losing water.  You might also apply some wet ash or cow dung to the top of the cutting to protect it from drying out or being damaged by rain.

It is wise to take cuttings from several different trees which have come from different sources.  Perhaps you can get a few cuttings from other farms as well.  This way, if a disease or pest attacks, some of your rooted cuttings may die but others may be able to resist the attack.

Plant the cuttings: Fill the container with sand or clean soil.  Water it lightly:  the sand or soil should be moist but not wet.  With a stick make a hole about 10 cm deep in the moist sand.  Insert the cutting in the hole at a slight slant.  More than half of the cutting should be buried.  That is, if the cutting has 6 nodes, 3 or 4 nodes should be buried in the sand.  With your fingertips, press the sand down firmly around the cutting.

If you are using boxes, pots, or beds, plant the cuttings 5 centimetres apart.  If you are using plastic bags, plants 3 or 4 cuttings in each bag.

Keep the cuttings out of the direct sun, under a tree or in a shed, if you have planted them in containers.  If they are planted in a bed, shade it with leafy branches or palms fronds.

Water the cuttings enough to keep the sand moist but not wet.  New roots cannot grow if the sand becomes dry and hard.  On the other hand, the young roots will rot if they stand in water.  Take special care not to overwater cuttings in plastic bags.

Transplant the cuttings: You will know that the cuttings have taken root when they begin to put out new leaves.  When a cutting has grown 4 or 5 new leaves, it is ready to be transplanted to the field bund or hedgerow where you want it to grow.

Dig a hole wherever you want each new tree to grow.  Mix the soil you have dug out with compost or manure and put it back into the hole, filling almost to the top.

Carefully lift out the rooted cutting without hurting the roots.  Hold the cutting upright in the hole and cover the roots with the remaining soil.  Press the soil firmly in place around the cutting.  Then water it gently.  Shade the new plant from strong sun for the first few days until it is used to its new home.  And if there are animals around, make a guard around the plant to stop the animals from eating it or trampling it.