This page includes; propagation, propagate, cutting, flowering shrub propagation, propagating flowering shrubs, how to propagate with cuttings.
TYPES OF CUTTINGS
Stem Cuttings are cut straight across the stem, just below the tip, where the current seasons growth commenced.
Basal Cuttings are side shoots that have been sliced off with a sharp knife at the joining with the main stem.
Heel cuttings are side shoots that have been pulled off down the main stem so that they have a sliver of that main stem at the base.
Heel cuttings generally root better than Basal cuttings and Basal cuttings more easily than Stem cuttings with a few exceptions.
In my class I demonstrate the types of cuttings on readily available Rosa multiflora.
CONDITIONS THAT CAN PROMOTE ROOTING IN CUTTINGS
Water must be available to the roots in the soil and as water vapor to the leaves in order to reduce the rate at which they dehydrate.
Oxygen must be present around the base of the stem in the area that roots will be produced.
Light must be available as the essential fuel for photosynthesis, the primary source of energy for growth.
Temperatures between 54 and 72 degrees F seem to promote the processes that affect root development the most.
HORMONES EFFECT ON ROOT PRODUCTION
Hormones are responsible for the recognition by the cutting of the absence of roots and the need for them.
Roots seem to be produced wherever there is a particular kind of hormone called Auxins.
Auxins concentrate in areas adjacent to cellular damage to either promote healing or root production depending on nead.
Auxins produce cells that grow into embryonic roots that mature into the kind of roots cuttings depend on.
High concentrations of Auxins encourage the production of embryonic roots to a point but then prevent further development.
Rooting hormones should be aplied only to the base of the cutting and the excess shaken off. Too much may prevent the growth of mature roots.
Wounding is a method by which the propagator can improve the performance of cuttings which have proven reluctant to root. The removal of a small sliver no more than an inch long from the side of the cutting directly adjacent to the cut will sometimes attract more auxins to the site and may also remove a scab that would otherwise deter root production.
In my class I demonstrate wounding and I apply rootone to a cutting.
CUTTING MIX NEADS
Dense enough to support cuttings so they dont fall over
Porous enough so that the respiration of the cutting is not retarded.
Be able to hold as much moisture as possible for as long as possible.
CUTTING MIX MATERIALS
Peat clogs the spaces between particles with dust. If allowed to dry out its difficult to rewet.
Vermiculite
Perlite
I use two parts perlite to one part vermiculite.
In my class I show samples of each material. I also show everyone the mask I use when mixing these materials.
EFFECT OF FERTILIZER ON ROOT PRODUCTION
Root production can be prevented in cutting mixes that have fertilizer in them because of the presence of mosses that grow, clogging the air spaces that provide oxygen diffusion and respiration for the cutting. The growth of mosses is reduced in unfertilized cutting mixes. By the time moss starts reducing respiration rates the cutting will have produced enough roots to find the addition of nutrients welcome.
STICKING CUTTINGS
Water your mix thoroughly.
Make holes where each cutting will be inserted. I use a fresh unsharpened pencil.
Cuttings should be inserted no more than half an inch. A quantity of cuttings (all the same variety) packed closely together in the same 3 inch by 5 inch rectangular pot can help support each other.
In my class I demonstrate the above.
CUTTING CARE
Cuttings should be left undisturbed in their propagator or cloche for 6 weeks.
As long as the cuttings remain green, their stems remaining undecayed, there is a chance they may produce roots. Peter Thompson in his book "Creative Propagation" indicates that conifers sometimes take 18 months to root (Thompson, 79).
The best way to keep them green for the required period of time is in some kind of incubator.
MIST PROPGATION
Mist propagation is not necessary for the majority of plants but can be useful for some difficult varieties. In a mist propagation system the air around cuttings is kept saturated with a fine spray of mater. High light intensities may be maintained and cuttings will root faster. Cuttings can be simply set out on a bench in the greenhouse.
The problem is that when something goes wrong you can lose your entire crop to the burning effects of direct sunlight or to drowning when to much moisture is aplied. An enclosed propagator is usually much simpler to set up and provides less opportunity for things to go wrong.
MY PROPAGATOR
All commercial propagators I have talked to have designed their own propagator. Talking about them usually involves comments like "if I did it again I'd do it different." My own propagator is described below.
The size is determined by the heat mat that is 5 feet long and 12 inches wide. Two propagators fit into one of my bench coldframes (12 feet long by 3 feet wide with hinged polygal top) at Azalea House without crowding. Each propagator has a plexiglass top and is insulated inside with foam and then lined with poly. The sand is several inches deep on top of the heat mat (I replace the sand every few uses). A piece of plexiglass is atached to the top air tight.
I lay a piece of bubble wrap over the propagator when in use and keep it in the shade of my crab apple trees. If the propagator is in the coldframe a piece of expanded metal is laid on top to protect the polygal and to provide part shade.
In fall of 2003 I talked with Mr Cash at The Plant Sciences Building at Cobleskill Ag & Tech College. He is using an unenclosed propagator that has no sand in it because as he says the heat mat has to warm the cold moist sand first which uses more energy. Of course its in a heated greenhouse under mist propagation. He uses a different type of switch that he believes is less likely to go wrong for his misting system (he also has an alternative to the dositron that is more efficient). My system doesn't require any mechanical aids.
I may show everyone a mist unit and my propagator.
CLASS
I am teaching a class on propagation on thursday, March 11, 2004 Voorheesville Continuing Education Program
The above is my course outline.
Questions presented to me at that time will later be added here.
BOOKS
"Creative Propagation" by Peter Thompson ISBN 0-88192-251-X published by Timber Press, Inc., The Hazeltine Building, 133 S.W. Second Ave., Suite 450, Portland, Oregon 97204-3527, USA