The technique involves steeping willow cuttings in water for a number of weeks to produce a liquid that could promote rooting and reduce the stress on weakened trees. (AND NOT TWO OR THREE DAYS AS I PREVIOUSLY STATED) This is known to have been used as a method for propagation before commercially available rooting hormones were developed. Willow (Salix species) have long been known to root easily; cuttings from branches up to 5 or 6" thick can be taken at any time of year, placed in regular water and they will root within a matter of weeks. There is no need to apply rooting hormone to the cut end yet almost every cutting will still take root. This simple technique involves using the water that is left over from this cutting process (Willow water) to promote stronger rooting by using it to water cuttings, air-layers, yamadori (collected trees) and weak trees with poor root systems. The Theory Behind Willow Water Aspirin mixed with water has long been used by many to prolong the life of cut flowers and to increase the strike rate of cuttings. Aspirin is a natural anti-coagulant; meaning it stops/slows the processes by which fluids are converted to solid states/congeal. Some may also know Aspirin for it blood-thinning properties. Aspirin would seem to have a similar effect on plants, hindering the ability of the plant to clot up the damaged/cut end of a cutting or root and promoting the ability of water to enter the cutting and so sustain the plant itself whilst it self-heals. Interestingly, Aspirin is derived from salicylic acid, a product naturally found in Willow bark! There may also be other chemicals/hormones involved that promote rooting but the salicylic acid seems to be the primary cause. There is evidence to show that Salicylic Acid has an influence on blocking the wound response and effect of Abscisic Acid. Abscisic Acid is a stress hormone released by all plants in response to wounding or disease; it induces rapid closure of plant stomata and the 'shutting down' of injured areas of a plant. So we come full-circle, the Willow cutting releases chemicals into the water, this promotes its ability to absorb water and to take root. This water is then free for us to use to promote rooting in other plants!
I'm glad to here about the willow water, I have 2 massive willows in my yard. I'm going outside right now. Thanks for the useful info.
Up until the 1800's the main source of Salicylic Acid was willow trees, specifically the bark. In fact, willow tree-bark tea is still used in many area's for pain relief, and you can buy it at many health-food stores.
I tried it last year. It did not appear to work with any success. Albeit it was my first attempt at cloning. I have had much better, and consistant cloning success with a bubbler.
