Weeping Willow (Salix babylonica)
Willows are an amazing tree that have captivated humanity since time immemorial. They appear in the ancient legends, tales, folklore and customs of the Chinese, Egyptians, Greeks, Brits, Celts and American Indians. They even feature in three of William Shakespeare’s plays, Hamlet, Othello and Twelfth Night.
Some folklore associated with willows is fascinating – my two favourites are are that it is bad luck to tell a secret while standing under a willow, as the wind that blows through the leaves will reveal the secret to everyone, and that striking an animal or a child with a willow twig will stunt their growth! They did have some strange ideas way back in Medieval Europe!
Surely, there is something “magical” about these trees, for them to capture our attention so strongly.They have some interesting and unique properties, as we’ll explore in this article!
Willows – A Brief Introduction
Willows are fast growing, deciduous trees that are mainly found found in the the Northern Hemisphere, in cold arctic and north temperate zones, in regions with moist soils. The Weeping Willow appears to be a native of extra-tropical Asia, from Japan and China to Armenia and the banks of the Euphrates, and of Egypt and North Africa.
One of the most popular and familiar willows is the Weeping willow (Salix babylonica), it has exceptional form and beauty. When mature it exhibits graceful, wide-spreading, pendulous weeping branches, with a short trunk, and a broad rounded crown. Its leaves are thin and narrow, sometimes with whitened or silky undersides. It is fast growing, and adaptable to almost any soil conditions.
Willows are an incredibly useful tree, they have many useful functions:
- 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)
- Source of Material for Construction and Manufacturing – Willow wood is used to make furniture, tool handles, wood veneers, and toys. It is used in wood turning as it is easily worked, and is also used to make cricket bats. Willows are a source of wicker for basketry (weaving of wicker baskets) and for making fish traps. The wood can also be used as a source of fibre for making rope, string and paper. Charcoal used by artists is exclusively made from willow.
- Source of Energy – Willow is grown for biomass, a renewable energy source which reduces the need for fossil fuels and petroleum products. Willow can be converted into a variety of sustainable environmentally-friendly resources, including: 1. heat and electricity by direct combustion, co-firing with coal, and gasification; 2. biodegradable plastics and other polymers; 3. biofuels.
Willows are an ideal source of biomass because 1. Willows are easily propagated from unrooted cuttings; 2. High yields can be obtained in a few years, 3. Willow’s genetic diversity and short breeding cycle can be utilized to produce improved varieties; 4. Willows vigorously re-sprout after each harvest; 5. The amount of heat in a dry ton of willow is similar to other hardwoods.
Large scale projects to support willow as an energy crop are already at commercial scale in Sweden, and in other countries there are being developed through initiatives such as the Willow Biomass Project in the US and the Energy Coppice Project in the UK. (Ref: College of Environmental Science and Forestry – The Willow Biomass Project)
- Ecological/Environmental Uses – Willows have many beneficial environmental uses. They can be used in the following areas:
Riparian buffers – Natural barriers that prevent chemicals from entering streams, ponds, and lakes.
Phytoremediation – Willows clean up toxins from contaminated sites.
Wastewater management (biofiltration) – Willows filter contaminants from wastewater, and can be used in ecological wastewater treatment systems.
Environmental protection and preservation – Willows are often used for land reclamation, streambank stabilisation (bioengineering), slope stabilisation, soil erosion control, shelterbelt and windbreak construction, soil building, and soil reclamation.
Environmental reconstruction – Willows are used for constructing wetlands and wildlife habitat.
Gardening – Willows are used for in the construction of hedges, “living fences” and other living garden structures and general landscaping
Living snowfences – Strategically planted willows trap drifting snow.
Farming – Willows can used by farmers as an animal forage to feed their stock.
- Horticultural Uses – Willow bark contains natural plant growth hormones which can be used for rooting new cuttings. This is the area that we’ll be looking at in this article!
One of the most amazing properties of willows is their growth! Coppicing a willow (that is cutting it back to ground level) will result in numerous rods growing from the base that will grow at an amazing rate of 1.2-3.0m in a single season. A broken willow branch left in water will grow roots. Willows successfully root from very thick pieces of stem, this method is known as taking “trunk cuttings”, and a stem as thick as a human thigh will take root of put into damp ground. Willow cuttings can even grow if put in upside-down (but please do the right thing and put them in the right way up)! This property of willows is due to the naturally occurring plant rooting hormones that they contain. We can take advantage of this naturally occurring hormone, and make extracts that we can use to induce rooting on cuttings of other plants.
“Willow Water” – How it Works
“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.
As you can see, this is a garden potion that is really easy to brew up, and it keeps in line with the Permaculture principles of avoiding waste and caring for the Earth – no purchased synthetic chemicals, containers, it’s all natural, and best of all, free! So, next time you’re out on a hot summer’s day enjoying the shade and natural cooling provided by a majestic willow, grab a few twigs and take them home to help you in propagating plants for your garden!