- Buy or build a plant press.
- Select your specimen. Tag it in the field and assign it a number. Record the number on the tag and in your field journal, along with notes about where you found it, when, and any other observations that might help with identification.
- Bring the specimen back to the classroom either in a rigid container (to keep it from being crushed) or a plastic bag. A moist paper towel in the container will help prevent the plant from wilting. If you have taken a plant press along, you can proceed with the next steps right in the field.
- To press the specimen, clean up the plant. Brush off loose soil and blot off moisture.
- Arrange the plant on a sheet of newspaper. Next to it, place the identification tag with its name, a number you have assigned to it, the location where it was collected, when it was collected, and by whom. Make sure the same information is in your journal. Place another piece of newspaper on top of the plant.
- Make layers. Place the pieces of newspaper with your specimen inside between two pieces of blotting paper, then between two pieces of corrugated cardboard, to allow air to circulate.
- Place the resulting package in the plant press and gently screw it down. As an alternative, you can hold it securely together with straps, or place some heavy objects (books, bricks) on top.
- You can dry several plants in the press at one time. Each should be arranged in the same layers as described above.
- Check the plants every two or three days, and replace the damp papers with dry ones. It will take from two to four weeks before the specimens are completely dry.