Cottonwood

Winter’s Balm, First Medicine, Water Keeper.

As I walk along the river I notice giant cottonwood trees towering above the tops of the alder and the big leaf maple. Luckily, a windstorm has knocked down large branches with swollen buds, making my work easy. These are the prize I am after. As I squish the buds, a reddish resin sticks to my fingers. It has a strong fragrance all it’s own – reminiscent of pine and honey. This resin contains a medicine that eases pain and heals damaged skin.

Other names: Black Cottonwood, Balm of Gilead, Populus trichocarpa

Identifying Cottonwood: This massive tree grows 150-200 feet tall and can often be spotted towering above alder groves. Grey bark becomes deeply furrowed with age. Winter buds are large and full of fragrant yellow to red resin. Leaves are shiny and dark green above and silvery below with rounded to heart-shaped bases and finely toothed edges. They turn yellow in the fall and form a thick layer of mulch on the forest floor. Male and female flowers grow on separate trees. Male flowers are reddish pint and droop down in a catkin shape. Female flowers form 4-inch-long catkins with light green capsules. The ripe capsules split into 3 valves and release seeds with white, fluffy down that are carried great distances by the wind. Cottonwood fluff can be so thick that the tree is called “snow in summer.” Cottonwood is in the Salicaceae or willow family.

Where it Grows: Cottonwood is commonly found on the margins of streams, rivers and flood planes. It forms dense colonies in wet bottomlands and also grows in drier sites from sea level to mid elevations. Black cottonwood grows from Southern Alaska to Northern California mainly west of the Rocky Mountains. Other species of cottonwood including Balsam poplar (P. balsamifera), plains cottonwood (P. deltoids var. occidentalis) and narrowleaf cottonwood (P. angustifolia) found throughout the U.S. and Canada, and can be used interchangeably.

When to Harvest: Buds appear on cottonwood trees from late winter to early spring. You can smell the fragrance in the air on the first warm days. Just before they open, the leaf buds will exude a drop of red to yellow colored resin. When you pinch the buds and see resin inside, it is the perfect time to harvest. You will notice that some of the buds have catkins inside. These do not have as much resin and are less preferred for medicine than the leaf buds.

If you are lucky, a windstorm will knock down the tallest branches for you. These are the ones with the largest buds. Snap the buds off the branches and place them in a plastic bag. Sticky resin will adhere to your fingertips and anything else it touches. While it smells wonderful, this can be a very messy endeavor. To remove it, rub your hands with oil or rubbing alcohol, then wipe them off with paper towels. Try rubbing your hands with salve or an oily lotion before gathering them. The oil will help prevent the resin from sticking to your fingers.

Eating Cottonwood

Cottonwood catkins are rich in Vitamin C. They can be eaten raw or added to soups. I consider them more of a starvation food, but you might find a delicious way to prepare them. Please let me know what you discover!

Cottonwood Medicine

“Populus” means the peoples’ tree. This scientific name comes from the fact that cottonwood has proved to be so useful over the centuries. Many parts of the cottonwood tree are medicinal. A compound called salacin, which is found in the leaves, buds and bark of cottonwood, has been proven to lower fevers and reduce inflammation and pain. The resin has been used to waterproof boxes and baskets, and the bark has been used to make buckets for storing and carrying food.

Cottonwood oil is especially helpful for swollen arthritic joints and sore muscles. It is deliciously fragrant and is added to lip balms, body oils and healing salves. The body oil is a nice after-bath moisturizer. It also makes excellent massage oil for sore muscles. Because cottonwood is high in antioxidants, it is useful for healing the skin, including sunburn. The buds are also antiseptic and can be added to other herbal oils to prevent rancidity and molding.

Making Cottonwood bud Oil

There are several methods for making high quality cottonwood oil. The most simple is to cover the buds with olive oil in a glass jar and let them sit for several months. Eventually the resin will fall out of the buds, but this method does not work well on wet years or if you are in a hurry to make oil. My favorite method involves heating and crushing the buds. This is a messy process but I promise it will be worth the effort.

You will need: Extra virgin olive oil (enough to cover the buds), a double boiler, a blender (only if you are making a large amount), a pressing cloth like muslin, a strainer and a glass jar for long-term storage. If you do not have a double boiler you can create your own by placing a small pot in a larger pot with an inch or two of water in it.

Step 1 – blend or pinch open the buds. This will help the resin to more easily release into the oil. If you have a small amount you can simply pinch the buds with your fingernail. Place directly in a double boiler and cover completely with olive oil.

For larger amounts, using a blender will save you a considerable amount of time. First, place your buds in a double boiler and cover them with olive oil so they are fully covered ½ to 1 inch above the buds. (If you put the buds in the blender directly without oil they will stick to the sides and your clean up will be much more challenging). Pour oil and buds into the blender. Turn on and blend just until the buds are mostly broken open. Place back in the double boiler.

Step 2 – Gently heat.  Heat on a very low setting. Do not allow the olive oil to get hot enough that it boils! You can turn the burner on and off to keep the temperature low. Heat for several days. The oil will turn a deep golden color and become very fragrant.

            

Step 3 – Press out the oil. Lay a piece of muslin cloth over a strainer that is sitting on a container. Pour a couple of cups of buds and oil into the muslin, bundle it up, twist the cloth and squeeze with all your might. Once oil stops dripping, empty the buds into a compost container and continue pressing until done. Let the pressed oil rest for an hour or so. If there is any water or solid material it will fall to the bottom of your container.

Step 4 – Store. Pour your oil (minus any water or solids that might be at the bottom) into a glass storage container. You can use any glass jar with a tight fitting lid. Amber jars are nice because they protect the oil from sunlight, but you can keep clear glass containers in a cupboard in a cool place and the oil will preserve just as well. Remember to label – although the smell of this oil makes it easy to identify.

Helpful hint: to clean your containers, wipe oil off with a paper towel and then clean with soapy water. It is easier to get resin out of a double boiler when the oil is warm. If resin remains, wipe with a paper towel soaked in rubbing alcohol (the higher the alcohol content the better). For extreme cases you can soak with a little alcohol overnight.

Caution:  Although I have never heard of anyone being allergic to cottonwood bud oil, you may want to avoid it if you are allergic to bees or aspirin.

Ecological Relationships: Cottonwood and willow trees often grow in profusion on the banks of rivers and wetlands. The seeds are easily carried in the wind and will take root and grow rapidly in moist disturbed soil. They provide shade that keeps the water cool for salmon and other species. They create a canopy of filtered light and deposit rich leaf mulch that supports a vibrant habitat for shorter deciduous trees, shrubs and herbaceous plants. Insects make homes in soft cottonwood trunks and woodpeckers hammer holes to find them. These cavities become nests for birds, squirrels and raccoons. Eagles, osprey and great blue herons make platform nests in the upper branches of cottonwood. Beavers eat cottonwood and also use them to build dams.

Cottonwood resin is called “bee glue” because bees gather it to seal up their hives to protect them from invading insects and microbes. It is an ingredient in propolis.

Cottonwood and willow trees produce a rooting hormone – an ingenious adaptation that helps broken branches that float down rivers or streams to root in the banks, thus spreading their range. This hormone will help other plants to root as well. See my Willow blog post for the recipe. Cottonwood will readily sprout from a small piece of broken root, a stump or even a stick place in the mud.

References

Arno, S. and Hammerly, R. Northwest Trees. 2007. The Moutaineers Books.

Grey, B. The Boreal Herbal. 2011. Aroma Borealis Press.

Pojar, J. and MacKinnon, A. Plants of the Pacific Northwest Coast. 1994. Lone Pine

Randall, Keniston, Bever and Sensen. Manual of Oregon Trees and Shrubs. 1998.