It's August and time for the 'toothpick' technique
I have not posted this propagation method in several years. Time for a repeat. Just a reminder that all cuttings need to callus before they will root. This method allows the callusing to take place on the mother plant before the cutting is removed and is most helpful for those hard to root trees/shrubs. Plan to use the toothpick technique during the last weeks of August up until mid-September. This is a little known process and when I first posted it a number of growers contacted me, pleased to know about it as it requires no misting systems, etc.
A very sharp, small penknife or Exacto knife.
A small block of wood (to prevent cutting fingers!)
Some colored yarns or tape for marking purposes.
THE TOOTHPICK PROPAGATION TECHNIQUE
1. Select the stem from which you wish to take a cutting. Look along it until you locate a bud ON LAST YEAR'S GROWTH.
2. Place the block of wood behind that point and make a single VERTICAL cut all the way through the stem, just below the bud.
3. Insert a toopick through the cut.
4. Mark each cutting with colored yarn/tape so that you can locate it at a later date.
5. Walk away from your toothpick cuttings until the end of October or November. Leave them alone!
6. REMOVING THE CUTTINGS FROM THE MOTHER PLANT.
You will note that a callus has formed where you wounded the cutting and inserted a toothpick. With sharp pruning shears remove the cutting just below the toothpick. Trim off the toothpick on either side of the cutting.
7. Dip your cuttings in rooting hormone and set them in a cold frame. Water well and close up the frame for the winter. Water as needed. If you do not have a cold frame, set the cuttings right next to your house foundation on the east or north side. Lean an old window or glass pane up against the foundation to protect them.
8. Rooting should take place by mid-spring. Those with greenhouses can leave the cuttings on the mother plant into December/January before setting them to root. Commercial propagators will find this useful.
A VARIATION OF THE TOOTHPICK TECHNIQUE
This method requires a bit of practice but works well. In August/September select the stem to be used as a cutting. Locate last year's growth on the stem and grasp it between thumb and forefinger. Snap the stem lightly until it breaks in half. Leave it hanging on the plant where it will callus. Then follow instructions above for setting cuttings. Snip the cutting off, when callused, at the wounded part. This is a useful technique for azaleas and many woody shrubs and Japanese maples.
Hopefully I have explained this method so it is understood. Reading it over a few times may be necessary.