As winter turns to spring, I have been noticing the trees. Trees are optimists. Even as the leaves yellow in the fall, the trees are preparing for the spring, storing nutrients for the cold months ahead and growing small new leaf buds that wait for the sun to return and the sap to rise. My eyes go up as I walk through the winter woods, scrutinizing bark and bud. Every year I have the immense pleasure of getting to know the trees, and their wisdom, a bit better. Trees help prevent erosion and play a huge role in climate support by removing carbon dioxide from the atmosphere. They produce oxygen, food, and habitat for other living beings, as well as medicine. They are the cornerstone of many ecosystems. Trees and shrubs offer all sorts of amazing medicines from every part of the plant, depending on the species. These range from seeds (including nuts, berries, and fruits), sap, pollen, bark, twigs, leaves, flowers, and buds. If we are going to harvest tree medicine, let us first think of the trees.

A Few Simple Wildcrafting Rules to Remember:

Never harvest roots if bark will do.
For bark medicine, trim branches.
Never cut the bark off live tree trunks, or girdle the tree by removing the bark all the way around a trunk. This cuts off the tree’s ability to move nutrients up the trunk and it will die.
With the spring thaw often comes downed branches and trees. This is a great way to harvest roots, bark, twigs, and buds.
Remember, buds turn into leaves. If you take too many buds from a young tree (they are easier to reach, right?), you are compromising that tree’s ability to photosynthesize and hurting it’s potential to make nutrients and thus survive. Do this over several years and that tree will have a harder time surviving through rough patches like drought or early freezes.
Only harvest excess sap. Sap is kind of like tree blood; it carries water, hormones, and nutrients including sugars and minerals. It is essential for the health of a tree. Always leave enough sap on the tree to cover injuries and insect holes.
Very importantly, make sure you identify your tree correctly before harvest. (See resources at the end of this article.)

Coniferous vs. Deciduous Trees

Most conifers are evergreens and have needles or scale-like leaves. They tend to live in less hospitable environments like mountains and other areas exposed to the elements. Conifers generally need less water, nutrients, and light than deciduous trees. Their needles and sap are high in volatile oils, which can be antimicrobial, stimulating, and warming, but also tend to be irritating to the kidneys, especially in large doses. Because they are evergreens, they generally store medicine in their bark and leaves more evenly throughout the seasons. Deciduous trees have less durable leaves, which they drop during the fall. They tend to need more nutrients and grow by water, such as rivers, streams, lakes, and seeps. If you see a stand of willow or cottonwood that isn’t by a river, you can bet they have found an underground water source. Deciduous trees are generally best harvested in the spring, summer, or fall depending on the part of the tree you are using.

The Parts and When to Harvest:

Bark and twigs: all year, although late winter to early spring is best
Pine pitch or sap: all year
Buds: spring
Flowers and Leaves: spring to summer
Seeds and Nuts: late summer to fall

Some Medicinal Trees and Shrubs of North America:

Deciduous Trees:

Alder (Alnus spp.)
Apple (Malus domestica)
Ash (Fraxinus)
Aspen (Populus tremuloides)
Beech (Fagus )
Birch (Betula spp.)
Black Walnut (Juglans nigra)
Cascara Sagrada (Rhamnus purshiana)
Elder (Sambucus spp.)
Ginkgo (G. biloba)
Hawthorn (Crataegus spp.)
Hazel (Corylus spp.)
Horse Chestnut (Aesculus hippocastanum)
Linden (Tilia spp.)
Maple (Acer spp.)
Oak (Quercus spp.)
Poplar or Cottonwood (Populus spp.)
Red Osier (Cornus spp.)
Red Root (Ceanothus spp.)
Slippery or Elm (Ulmus rubra) or due to scarcity, it is better to use Siberian Elm (Ulmus pumila)
Sumac (Rhus spp.) (avoid the unrelated species of poison sumac Toxicodendron vernix)
Wild Cherry (Prunus serotina or P. virginiana)
Willow (Salix spp.)
Witch Hazel (Hamamelis virginiana)

Coniferous Trees:

Pine (Pinus spp)
Spruce (Picea spp.)
Larch (Larix spp.)
Cedar (Can refer to Cedrus spp., Pinus spp., Juniperus spp., or Thuja spp.)
Juniper (Juniperus spp.)

An Example of Tree Medicine--Poplar Bud Oil:

Poplar bud oil, also called Balm of Gilead, is one of my favorite herbal remedies to make in the spring. The smell is balsamiferously delightful. I open the jar of oil and feel like I am down by the river in the middle of spring, fingers sticky with dark red resin from the leaf buds. Poplar is high in salicin, making it anti-inflammatory and analgesic (pain-relieving). It is a rubefacient, meaning when applied topically it will draw blood to an area, thereby speeding healing and tissue repair. Its antimicrobial properties make poplar useful for preventing or treating infections of the skin, lungs, and urinary tract. Poplar bud oil is useful for body aches and injuries such as sprains, strains, sore muscles, bruises, and headaches. It is helpful for dermatitis, eczema, wounds, and cuts. The oil or salve can be used as a chest rub for congestion, cough, and respiratory infections.

How to Make Poplar Bud Oil:

Use 1 part of the fresh leaf buds by weight to 3 parts vegetable oil by volume.
I recommend using a cold-pressed fixed vegetable oil such as virgin olive oil when making herbal oils.
Putting the buds in a freezer for a day before processing makes them much easier to work with.
Put the frozen buds in a blender and sprinkle them with ethyl alcohol (such as Everclear). The alcohol will start extracting the medicinal properties of the poplar buds. Blend well and let sit for ½ hour.
Add the vegetable oil and grind again until the mixture is “soupy” and slightly warm.
Pour into a jar.
Make sure the herb is completely covered in oil. This won’t be hard with poplar, but if some herb is sticking out of the oil, it will likely mold.
Cover jar with a paper towel or cheesecloth to allow moisture from herb to evaporate.
Infuse for 2 weeks to 1 month in a cool, dark place.
Strain or squeeze out by hand through cheesecloth to avoid squeezing too much moisture from the plant into oil.
Add a teaspoon of Vitamin E oil to give your oil a longer shelf life and help prevent it from going rancid.
Herbal oils are best stored in dark glass bottles. Keep oils in the refrigerator to extend their shelf life.
Poplar bud oil has a shelf life of one year or more.

Tree ID:

Unlike many herbs, trees and shrubs can often be easily identified in the winter months. Here are some of the identifiers to look for:

Ecology: Where is it growing and what is around it? Does the tree thrive in the mountains, by meadows, along a river, in a forest? Does it like a wet or dry environment? Does it prefer the open areas, or need the shade of other trees?
Form: Look at the tree’s overall form. What are its size and shape? Does it have a single trunk or lots of smaller stems, such as a shrub? How far up do branches start growing?
Leaves: What size, shape, and color are the leaves? Do they have a lighter underside? Are they thin and needle-like? Are they scaled or evergreen? Do they drop in the fall?
Leaf scars: Are the leaf scars opposite each other or alternating? This will help you determine the leaf pattern even when there are no leaves on the tree.
Bark: Look at characteristics including color, texture, and thickness. Touch the bark. Does it feel spongy, flaky, or smooth? Scraping a bit of the outer bark away to reveal the inner bark. The inner bark can have distinct smells and colors.
Buds: Tree buds contain next year’s leaves, flowers, and stems. If available, what do the leaf and flower buds look like? Look at their shape, length, color, and if the buds have scales. Where are they located on the branches?
Flowers: If available, what kind of flower does the tree have? Many trees take advantage of their height by being wind-pollinated. Some trees have male catkins up high with female flowers (not too showy if they aren’t trying to impress a pollinator) on lower branches.
Fruits or Cones: Is there anything left hanging on the branches? Look under the tree for seeds, fruits, nuts, and cones.
Learn more about wintertime tree id here.

And Lastly, a Poem to Put You in a Forest Mood:

How to Feel the Sap Rising (a poem for summer)
Walk as slowly as possible,
all the while imagining
yourself moving through
pools of honey and dancing with
snails, turtles, and caterpillars.
Turn your body in a clockwise direction
to inspire your dreams to flow upward.
Imagine the trees are your own
wise ancestors offering their emerald
leaves to you as a sacred text.
Lay yourself down across earth
and stones. Feel the vibration of
dirt and moss, sparking a tiny
(or tremendous)
revolution in your heart
with their own great longing.
Close your eyes and forget this
border of skin. Imagine the
breeze blowing through your hair
is the breath of the forest and
your own breath joined, rising and
falling in ancient rhythms.
Open your eyes again and see it
is true, that there is no "me" and "tree"
but only One great pulsing of life,
one sap which nourishes and
enlivens all, one great nectar
bestowing trust and wonder.
Open your eyes and see that there
are no more words like beautiful,
and ugly, good and bad,
but only the shimmering presence of your
own attention to life.
Only one great miracle unfolding and
only one sacred word which is yes.
—Christine Valters Paintner

Tree ID Resources:

Conifers: http://www.conifers.org

Online Arbor Day resource for tree ID: https://www.arborday.org/trees/whattree/WhatTree.cfm?ItemID=E6

Winter Tree ID with limited species and some good pictures: http://www.sfi.mtu.edu/Urban_teachers/Winter%20Tree%20ID%20Clues.pdf Winter Tree ID Key: https://www.uwsp.edu/cnr-ap/leaf/Documents/LEAFWinterTreeIDKey.pdf

Dichotomous Tree Key: https://www.uwsp.edu/cnr-ap/leaf/Documents/LEAFWinterTreeIDKey.pdf

Tree and Shrub ID of Montana: http://www.msuextension.org/gallatin/documents/naturalresourcesdocuments/2B0323.pdf

Tree Medicine