Fall leaves can easily be preserved to maintain their color and flexibility. The preservation process provides leaves and twigs that are supple for identification and study. Leaves preserved in the manner outlined in this procedure will not crumble or become brittle. In fact, the pigments present, which are an identifying characteristic, will remain.
- Leaf preservation
Leaf preserving fluid*
Leaf sealer solution*
Tree identification key*
Tub with lid*
*Materials included in kit.
The Leaf Preserving Fluid and Leaf Sealing Solution are both potential body tissue irritants and should be treated accordingly. Wear chemical splash goggles and chemical-resistant gloves. Be especially alert if personnel have a history of skin allergies. Both solutions are very dilute—if skin contact occurs, simply wash with soap and water. This activity requires the use of hazardous components and/or has the potential for hazardous reactions. Please review the Safety Precautions section and relevant Safety Data Sheets before beginning this activity. Wash hands thoroughly with soap and water before leaving the laboratory.
Please consult your current Flinn Scientific Catalog/Reference Manual for general guidelines and specific procedures, and review all federal, state and local regulations that may apply, before proceeding. The Leaf Preserving Fluid and Sealing Solution can both be disposed of using excess water in a municipal drain system following the suggestions in Flinn Suggested Disposal Method #26b.
- Select firm fall leaves or leaves on a twig that will easily fit into the tub. Do not use leaves that are dried and brittle.
- Rinse the leaves in clean water and pat them dry with a paper towel. Be sure the leaves are free of dust and dirt.
- Arrange the leaves in the bottom of the tub. If you are preserving a small number of leaves, you may wish to use a smaller container.
- Mix Leaf Preserving Fluid as directed on the container. Pour enough Leaf Preserving Fluid into the tub to completely cover the leaves. Use the forceps to lift and arrange the leaves until the solution completely surrounds and covers leaf and stem surfaces. Any portion of the tissue left uncovered may become dry and brittle.
- Place the cover on the tub and place the tub in an area that receives light during the day. Do not place the tub in a drawer or other completely dark area as it might promote the growth of fungus.
- Within three to five days, the leaves should be preserved. Test the leaves by carefully bending the stem or a small section of a leaf. If the tissue is not supple, allow the leaves to soak for an additional day or two in the solution.
- When the leaves are preserved, carefully remove them from the Leaf Preserving Solution. Rinse the leaves in clean water. Pat the leaves dry with paper towels. The leaves should feel smooth and “leathery.”
- Place the leaves between sheets of toweling or absorbent paper (newsprint) to absorb any remaining water.
- If you plan to use the leaves for instruction over a long period of time, you should seal the leaves so that moisture is retained.
- To seal leaves, place the leaves in a clean tub and pour Leaf Sealer Solution over the leaves. Allow the leaves to set in the solution overnight. After this time remove the leaves. Rinse them with clean water and pat dry with toweling. Your leaves should now be ready for long-term use.
Leaf Preserving Fluid and Sealer Solutions can be reused several times. Store the solutions in closed, labeled containers in the refrigerator when not in use to prevent molding. Both solutions are water soluble and utensils are easily cleaned with water. Do not use soap as soap will “plug” up plant transport systems. Pigments that leach into the solution does not affect the solution and it can be reused even if discolored.
- For best results, store individually preserved leaves between sheets of toweling, newsprint or other absorbent paper in closed containers. Leaves properly preserved and stored will retain their color and stay supple for several seasons.
- Place a piece of white paper and the leaf in a plastic zipper-lock bag for an aesthetic presentation while classifying the leaves.
- Use the leaf specimens to practice using dichotomous keys for identification of trees. Use keys that are appropriate for your area. Many local conservation and agricultural departments have simple dichotomous keys for local plants.
Correlation to Next Generation Science Standards (NGSS)†
Science & Engineering Practices
Planning and carrying out investigations
Obtaining, evaluation, and communicating information
Disciplinary Core Ideas
MS-PS1.B: Chemical Reactions
MS-LS4.A: Evidence of Common Ancestry and Diversity
HS-PS1.B: Chemical Reactions
MS-PS1-2. Analyze and interpret data on the properties of substances before and after the substances interact to determine if a chemical reaction has occurred.
HS-PS1-2. Construct and revise an explanation for the outcome of a simple chemical reaction based on the outermost electron states of atoms, trends in the periodic table, and knowledge of the patterns of chemical properties.
MS-LS4-2. Apply scientific ideas to construct an explanation for the anatomical similarities and differences among modern organisms and between modern and fossil organisms to infer evolutionary relationships.
MS-LS4-4. Construct an explanation based on evidence that describes how genetic variations of traits in a population increase some individuals’ probability of surviving and reproducing in a specific environment.
Special thanks to Sally A. DeRoo of Dexter, MI, for the development of this activity.