…and how to make your own pressed flowers and leaves at home!
At Hoyt Arboretum, we make several hundred pressed and dried plant specimens every year to scientifically document and validate our tree collection. Many of the larger botanic gardens and arboreta, as well as most land-grant universities, have dried plant collections to record the existence of plant species at a given place and time, and these museum collections are called herbaria (singular: herbarium). Learn about the Hoyt Arboretum Herbarium here.
Herbarium specimens are intended to last for hundreds of years (for example, read about Lewis & Clark’s Herbarium), and at Hoyt Arboretum we use a multi-step process to create and keep track of each herbarium accession.
At home, you can press and dry your own plants using a plant press (if you have one), or by simply using newspaper, corrugated cardboard, and something heavy. Don’t ruin your valuable books by pressing plants directly in them!
To make pressed and dried plants at home (without any special equipment):
- Collect your flowers, leaves, etc. Trim them as you best see fit. (Friendly reminder that collecting plant material at Hoyt Arboretum is not allowed)
- Place those plant parts between sheets of newspaper in a pleasing manner.
- Stack those newspaper sheets with plants, between pieces of corrugated cardboard.
- Weigh down your stack (using bricks, rocks, books, cans of soup, etc.) and leave your stack in a warm place to dry. Outside in the sunshine with some wind is optimal, but a warm car or a dry garage works too!
Depending on your plant material, replace the newspaper every other day if your plants are still moist to the touch. Thin, dry leaves can dry within 1-3 days, and thicker plant material may take up to a week or longer to dry. Be watchful for mold if you have juicy, wet plants.
If you want your dried plants to look more studious, you can glue them to a journal with a name (scientific if you wish!), date and location collected, and any other associated plants or other notes about where you found it. You may also make cards, artful journal entries, or whatever sparks joy! Have fun with your plants!
About the Author
Dr. Mandy Tu works for Portland Parks & Recreation as the Plant Taxonomist and Herbarium Curator at Hoyt Arboretum. In this position, she is responsible for collecting voucher specimens and verifying the identity of the trees within the Arboretum and is often asked to identify plants by natural area managers in the Portland region. She has a B.S. in Botany from the University of Washington and a Ph.D. in Plant Biology from the University of California at Davis. Mandy has taught many plant identification courses and workshops for botanical professionals and plant enthusiasts.