What Part to Harvest and When.
I know we sometimes get a bee in our bonnet about a new herb. We hear how great herb XYZ is and we are eager to experiment. We want to harvest now – right now! But we need to know what part to harvest and when.
Imagine I invite you over for strawberry shortcake.
Unripe green strawberries
These are the strawberries I use. Will you have an accurate and delicious experience of strawberry shortcake? No. You will tell everyone that strawberry shortcake is awful. If I harvest oat seeds before they are at the milky oat stage – the tincture will have little value. Those plants will have been wasted, as well as all the time and energy spent to make the tincture. When I tell everyone that milky oat seed tincture “doesn’t work” I will be telling the truth but the why is obscured.
If we want herbs to work medicinally, we need to commit ourselves to using them correctly. We can divide herbs into three main categories when it comes to which part of the plant we use medicinally. Barks, roots, and aerial parts. Each part has a specific time of the season it is ideal to harvest. Knowing what part to harvest and when is foundational to herbalism. Ethical and sustainable harvest requires a commitment to harvesting the correct part at the correct moment.
Barks.
Cramp Bark – Viburnum opulus
Barks are best harvested early spring or late fall. I prefer autumn personally because I find it easier to access trees in the fall. Spring here often finds the ground still covered in snow and slush. My tree identification skills are the weakest of my plant identification skills so harvesting bark in the fall gives me the whole summer to observe a tree and ensure I have properly identified it. Do not harvest bark from the trunk of the tree. This opens the tree up to pests and disease. At campsites I will find trees, and someone has removed the bark from all the way around the trunk. This is girdling and kills the tree. The best way of harvesting bark is to step back and look at the tree. Are there branches crowding together? Damaged branches? Prune the tree to help it prosper. Ensure your tools are clean and sharp. A ragged cut makes it harder for the tree to heal and encourages disease. The collar of a tree is the junction between the trunk and the branch. Cut perpendicular to the collar.
Roots.
Burdock – Arctium lappa
Roots are best harvested either early spring or late fall. It is worth doing research on the plant you want to harvest to know what part and when. If you harvest dandelion root in the fall the amounts of inulin are higher. In the spring the roots are higher in taraxacin, a constituent in the roots that make them a cholagogue. What action are you looking for? Biennial and perennial plants respond in the fall to changes in temperature and changing light levels. Nutrients are no longer readily delivered to the aerial parts but are instead put into the root.
For roots I wait in the fall until the last possible moment before digging. This last moment varies with the species I am harvesting. Burdock is recognizable long into the fall. We also benefit from the fact that burdock plants like to hang out together. You will frequently see 2nd year plants with burrs nearby 1st year plants that are suitable for harvesting. An herb like gold thread, on the other hand, once the autumn leaves fall it will be difficult to find a colony unless you already know where it is.
Aerial Parts.
Ox-Eye Daisy – Leucanthemum vulgare
These are the parts of the plant that grow above ground. As we are heading into the heart of summer, we are entering the peak of harvesting season for aerial parts. Harvest the top quarter to a third of the plant. Harvest the plants early in the flowering period to allow the plant to recover and have a chance to reproduce. Some of the flowers should be open but not all of them. Pick aerial parts on a sunny day. Pick early in the day between when the dew has dried and before the heat of the day affects any aromatic compounds.
A paper bag allows your harvest to breathe. Just as with barks and roots, knowing what part to harvest and when is critical. Red clover, for example, is prone to rust. Harvesting late in the season means that those plants most likely have rust. Not something we want in our medicine.
I know how easy it is to be overtaken by enthusiasm. Particularly if it’s a plant known for assisting people with a condition that we struggle with. If we want to truly learn about a plant and the actions it has, it is worth it to take the time to learn what part to harvest and when. None of us are doing too well on the marshmallow test but we can try. Buy a product already made and start there with your experimentation. You and the plants will be the better for it.