Propagation - vegetative

Propagation by means other than seed, such as by budding, cuttings, grafting, division and layering.

Cuttings

CUTTING - A piece of a plant induced to grow roots and become a new plant.

Hardwood cuttings Are usually taken from shrubs, or trees, at the end of the growing season, from this year's growth. Dig a 'V' shaped trench about a spit (Spade depth) deep and put about 5cm of sharp sand in the bottom. Take your cuttings and have them about 12cm longer than the hole is deep. Dip the end in hormone rooting compound and place them in the trench, at about 6cm apart. Now fill the trench in and compact the soil by treading it down. The following spring they will start into growth. Leave them where they are through that year and dig them up the following spring.

Softwood cuttings

Are taken from shrubs, trees, or herbacious plants, using this year's growth, usually in early summer. They should be kept in a shaded place as the sun will 'cook' them. Before taking them prepare a seed tray or pot and have a clear cover ready, a large plastic bag will do. The compost can be either 50:50 peat: sand or 50:50 peat: pearlite. The peat may be substituted for another type of soil, such as coconut coia. Geraniums and Fuchsias are generally propagated this way.

Leaf cuttings

Many 'Indoor' plants can be propagated using their leaves, Begonias, Saintpaulia (African violets) and Sansevieria (Mother-in-laws tounge) are amongst them.

 

Take the strongest growth you can and remove any soft tips as these will rot. Leave about four leaves. Dip the end in rooting compound and insert into the compost, deep enough to avoid touching the bottom of the container. Make sure you press the soil firmly around each cutting. Water the lot thoroughly with a fungicide added. Now put the clear cover over the container.

leave them until new growth appears and if it is not to late in the season pot them on into individual pots.

With deciduous cuttings you should remove any leaves that will be below the soil level when potted, as well as any soft growth at the top.

Most Conifers are easy to root from cuttings (Pines being the exception). They can be treated as softwood cuttings, but will take longer to root. When removing them from the stock plant break them off with a 'heel' of old wood. Take all foliage that will be below soil level off as this will rot.

When potting up your cuttings, try to make sure they don't touch the bottom of the tray, or pot. To root successfully they must be surrounded by soil.

the cutting on the left of the illustration should be ok, the one on the right, in contact with the bottom of the tray will probably fail.

This of course applies to both deciduous and coniferous cuttings.

Here we see a Sansevieria leaf used for cuttings.

It would be sliced through with a sharp knife, treated with rooting powder and potted up.

Care should be taken to keep the segments the right way up, that's to say the way they were on the leaf.

Layering

A method of inducing roots to grow from the trunk, or branch, the top of which is then cut off, and grown as a new plant.

The technique may be divided into Ground layering, and Air layering

Ground layering

Where you fix a low growing branch into the ground (or a container). Anchor the branch to the ground with a steak, or cane to stop the tree moving, and mound soil over the area to be rooted.

The tree is usually left alone until the following spring when it may be dug up, and potted. If the tree is a conifer the best course of action is to carefully remove the soil around the cut to see if adequate roots have formed, replacing the soil if not. The tree should then be left for another year.

The trunk should be treated with a rooting compound as shown in the following section.

Air layering

This tree is being Air layered, the top part will be grown on to thicken it up, the bottom part will produce shoots, one of which will form a new leader that will eventually give a good tapered trunk.

The layering is wrapped in clear plastic, which will have a layer of black plastic put over it, as roots grow best in the dark. The black plastic can be opened when you wish to inspect progress, or check that the moss is still damp.

With both ground, and air layering, the technique below should be followed, noting the difference between deciduous, and coniferous trees.

 

The 'Ringing' method works well with deciduous species, however for conifers an alternative way is best. This involves wrapping a piece of strong wire around the trunk, and twisting it until it bites right into the bark. Then cut a number of small nicks in the bark just above the wire, and apply hormone compound, then wrap in moss.

Conifers take longer to root by layering, and may not show roots until the following year.

DIVISION

Many bushes, and shrubs can be propagated by division, winter is the ideal time to divide them, either by digging it up, and separating it or by breaking part of it (with some roots) off the major bush.

Many indoor plants, and herbaceous perennials can be divided. The indoor plants should ideally be divided when in growth. This would normally be during the summer months, when the length of daylight increases. Herbaceous perennials are best split in the spring.

Grafting

The reason for producing a grafted tree is to impart the growth characteristics of the rootstock onto the scion. Grafting is used almost extensively in the production of fruit trees where the producer may wish to make a tree that only grows to a height of say 10ft, but produces a normal crop of fruit, this could be achieved by grafting the scion onto a dwarfing rootstock.

Here we see a less vigorous white pine grafted onto a vigorous black pine rootstock. It may take a year or so to be sure the graft has taken. The cut has been bound with raffia to hold it closed. The graft will now be enclosed in a clear plastic bag, keeping the air around it moist.

 

Allen. C. Roffey Saturday, August 18, 2018 10:38