Propagating Native Plants

Stem Cuttings

Contents

Learning Objectives

Narrative

Handling
Rapid handling of all types of cuttings after removal from the stock plants is important. Cuttings should be kept in clean, moist conditions and out of the sun at all times. Soaking of cuttings in water to keep them fresh is undesirable for many species.
Trimming the Stem
If your cutting is too large or is not very fresh, the stem should be trimmed so that each cutting is 3 to 5 inches long. Cuttings should be as uniform as possible so that all material will be equally exposed in the propagating container. Make the basal cut 1/4 inch below a leaf node on a diagonal. If the terminal end needs to be trimmed also, cut perpendicular to the stem.
Trimming Leaves
Each cutting should have 2 or 3 leaves attached. Leaves are usually stripped from the lower third of the cutting before sticking it into the rooting medium. Pull or cut off the leaves without stripping the stem of the cambium layer. Some nurserymen reduce leaf size on cuttings to reduce water loss. However, retention of maximum leaf area will produce a stronger root system in a shorter period. All flower buds should be removed because they can hinder rooting of many species.
Growing Container and Medium
Any nontransparent disinfected container with drainage is acceptable for growing. A suitable rooting medium is half perlite and half sphagnum moss and some growers will also add sand to the mix. The planting mix must be sterilised either by baking or you may use a soil inoculant. It is desirable to have a porous medium so that the roots will not meet any obstructions.
Rooting Hormone
Rooting hormone is recommended as it helps to stimulate rooting, and often include a fungicide, which is a good idea given the damp conditions required for rooting success. Pour a small amount of the rooting hormone powder into a clean container to prevent contamination of all of your rooting hormone. Dip the base of the stem, including the node area, into the rooting powder. The stem should be dry when dipped. Tap off excess powder, because too much hormone can actually inhibit rooting.
Planting
Poke a hole in the medium before inserting the cutting to avoid loss of the rooting hormone. Because root initiation and growth require adequate oxygen, cuttings must be inserted into the medium at the proper depth, 1 to 1 1/2 inches, or about one-third the total length of the cuttings.
Growing Conditions
To create the conditions necessary for a plant to root from a cutting, high humidity, indirect light and soil temperatures of 70 to 80 degrees F are a good rule of thumb. These conditions may be created by keeping cuttings enclosed in a greenhouse, under glass or in a plastic bag tent in dappled shade. Label the containers and place them in a warm area where they will be shielded from direct sunlight, especially if they are under glass or plastic.
Care
Check the rooting medium every few days to make sure it remains moist. Remember you must transplant the cutting once the roots are sufficiently established as the rooting medium is devoid of nutrients. A light addition of nutrients to the water may be helpful but care must be taken not to over do it. Rooting may take anywhere from a few days to several months. After a few weeks, test for rooting by gently tugging at the cutting. If there is resistance, rooting has started and the plastic cover may be removed and the plant transplanted.
Key Points:

Exercises

  1. Have the students cut the flowers off of some carnations (or some sure-fire natives) that have been sitting around in a vase for a few weeks and stick some directly in the ground and some in containers at home. Keep a record of success and failure as well as growth rate between the ground and the containers. Most plants of this species will root quite readily without any hormone or temporary growth medium.

References

 
The content of the page was last modified 2008-05-07