I can see why asprin would cause root growth...salicylic acid is a natural rooting agent. The way of getting it naturally is to soak weeping willow stems in water
Source of Medicine – The use of willow bark dates back thousands of years, to the time of Hippocrates (400 BC) when patients were advised to chew on the bark to reduce fever and inflammation. Willow bark has been used throughout the centuries in China and Europe, and continues to be used today for the treatment of pain (particularly low back pain and osteoarthritis), headache, and inflammatory conditions such as bursitis and tendinitis. The bark of white willow contains salicin, which is a chemical similar to aspirin (acetylsalicylic acid). It is thought to be responsible for the pain-relieving and anti-inflammatory effects of the herb. In fact, in the 1800s, salicin was used to develop aspirin. White willow appears to be slower than aspirin to bring pain relief, but its effects may last longer. (Ref: University of Maryland Medical Centre, Medical Reference – Complementary Medicine – Willow Bark)Willow Water” is a homebrew plant rooting hormone that is easily made and can be used to increase the strike rate (growth of roots) of cuttings that you’re trying to propagate.
The way that it works can be attributed to two substances that can be found within the Salix (Willow) species, namely, indolebutyric acid (IBA) and Salicylic acid (SA).
Indolebutyric acid (IBA) is a plant hormone that stimulates root growth. It is present in high concentrations in the growing tips of willow branches. By using the actively growing parts of a willow branch, cutting them, and soaking them in water, you can get significant quantities of IBA to leach out into the water.
Salicylic acid (SA) (which is a chemical similar to the headache medicine Aspirin) is a plant hormone which is involved in signalling a plant’s defences, it is involved in the process of “systemic acquired resistance” (SAR) – where an attack on one part of the plant induces a resistance response to pathogens (triggers the plant’s internal defences) in other parts of the plant. It can also trigger a defence response in nearby plants by converting the salicylic acid into a volatile chemical form.
When you make willow water, both salicylic acid and IBA leach into the water, and both have a beneficial effect when used for the propagation of cuttings. One of the biggest threats to newly propagated cuttings is infection by bacteria and fungi. Salicylic acid helps plants to fight off infection, and can thus give cuttings a better chance of survival. Plants, when attacked by infectious agents, often do not produce salicylic acid quickly enough to defend themselves, so providing the acid in water can be particularly beneficial.
Willow water can be made from cuttings of any tree or shrub of the willow family, a group of plants with the scientific name of Salix. The more cuttings that are used and the longer they are soaked in water, the stronger will be the resulting willow water. Recommendations for the exact method of soaking vary. Cold water can be used, and soaking times of four or more weeks are often quoted. Other gardeners use boiling water to steep the willow twigs and soak the mixture for around 24 hours.
How to Make “Willow Water”
Here is the procedure for making willow water:
Collect young first-year twigs and stems of any of willow (Salix spp.) species, these have green or yellow bark. Don’t use the older growth that has brown or gray bark.
Remove all the leaves, these are not used. Don’t waste good green material though, compost the leaves or throw them in the garden as mulch.
Take the twigs and cut them up into short pieces around 1" (2.5cm) long.
The next step is to add the water. there are several techniques to extract the natural plant rooting hormones:
a) Place the chopped willow twigs in a container and cover with boiling water, just like making tea, and allow the “tea” to stand overnight.
b) Place the chopped willow twigs in a container and cover with tap water (unheated), and let it soak for several days.
When finished, separate the liquid from the twigs by carefully pouring out the liquid, or pouring it through a strainer or sieve. The liquid is now ready to use for rooting cuttings. You can keep the liquid for up to two months if you put it in a jar with a tight fitting lid and keep the liquid in the refrigerator. Remember to label the jar so you remember what it is, and write down the date you brewed it up, and to aid the memory, write down the date that it should be used by, which is two months from the date it was made!
To use, just pour some willow water into a small jar, and place the cuttings in there like flowers in a vase, and leave them there to soak overnight for several hours so that they take up the plant rooting hormone. Then prepare them as you would when propagating any other cuttings.
The second way to use willow water is to use it to water the propagating medium in which you have placed cuttings. Watering your cuttings twice with willow water should be enough to help them root.
