LAWRENCE, Kan. – Leaves have started falling from deciduous trees in the Lawrence area, and some admirers might want to pick up a few of the prettiest leaves and take them home. But these small ornaments of fall quickly dry and fade — unless they are preserved or made into art.
Pressing leaves is the traditional way of preserving them. There are a few ways to do it, and you can use other methods to lengthen their storage life once they’re pressed, if desired. How long they last depends on the species, method, moisture content and whether additional preservation methods are used.
Longer-term preservation of leaves can be done with contact paper, wax paper or glycerin. While these methods typically help leaves retain their color and quality for longer periods of time than simple pressing, the actual shelf life depends on the same factors listed above. You could also paint the leaves, or you could make leaf rubbings or leaf skeletons that last indefinitely.
For any of the projects, try to select leaves that are free from insect damage and spots that could indicate presence of a plant disease.
To press leaves, simply place them between the pages of a book, between two books or between other heavy objects. Use a formal leaf press if pressing lots of leaves. You can either purchase a leaf press or make your own with plywood, bolts and wing nuts. Use paper towels, paper, newspaper or other absorbent material to separate leaves and prevent them from staining or damaging the items used to press them. Leave them in the press for a few days to a week or more depending on the species and desired result.
A simple method of preservation after pressing is to use contact paper to stick the pressed leaf to poster board or card stock. This reduces exposure to the elements and physical damage that occurs over time.
Pressed or unpressed leaves can be preserved between sheets of wax paper. Place towels underneath and on top of the paper and iron at high heat without steam. Work carefully to keep leaves from shifting or wrinkling in the paper. After the wax paper has warmed enough to seal around the leaves, allow it to cool and cut the leaves out, leaving a small margin of wax paper around the edges.
Glycerin preservation keeps leaves colorful and fresh for many years. For this method, mix one part liquid glycerin to two parts water in a shallow pan or bowl that is large enough to hold the leaves. Place the leaves in the mixture and use a heavy object to keep them submerged. Check after two to three days. When leaves are ready to remove from the solution, dry them on towels before using in further projects.
Painting leaves is a quick and easy method of preservation — simply paint the leaves the desired color using spray paint. Use leaves that are already dry, or dry them prior to painting.
To make leaf rubbings, seek out leaves with prominent veins. Place one or more leaves under a sheet of paper, then rub a crayon flat across the paper to make the outline and veins show through. Use single specimens or create collages.
Leaf skeletons are leaves that have lost all their tissue but still have their veins intact. To make them, use thick leaves with prominent veins, such as oak, maple or cottonwood leaves.
One method for making leaf skeletons is the soaking method. Place leaves in water and keep them submerged for a few weeks until most of the tissue has deteriorated and can be brushed away from the remaining veins. Remove leaves from the water at that point and use a toothbrush to brush away the softened tissue. Change the water every two to three days throughout the process.
Another method for making leaf skeletons is to cook them in baking soda and baking powder. Put leaves in a pan or pot, cover with water and mix in baking soda and baking powder in an equal ratio. One tablespoon of each to approximately four cups of water should be adequate. Bring this to a boil, then reduce to a simmer and stir occasionally. Add water as needed to keep leaves submerged. Cook until leaves have softened enough that the tissue can be gently brushed away in a similar manner as above.
You can also use washing soda (sodium carbonate) instead of baking soda and baking powder. Washing soda is difficult to find, however, and users should wear gloves and goggles while working with it. Use 1/2 to 3/4 of a cup of washing soda to approximately four cups of water. Bring to a boil, then simmer until leaves are ready for brushing.