If only we could capture the beauty of autumn and hold it to our hearts all winter
long! One of the spectacular features of fall is the wonderful coloring of tree
leaves. The more curious among us might wonder just how does fall color develop
in trees? It's a story that's been told before, but here it is one more time.
purpose of plant leaves is to harness the sun's energy to feed the tree. It does
this by way of the chloroplasts in leaf cells. The chloropalsts contain the green
plant pigment, chlorophyll. This pigment enables the leaves to capture the sun's
energy to make sugars and oxygen from carbon dioxide and water. During the growing
season the chlorophyll in present in abundant quantities. As the weather turns
cool the fall and the days shorten, the leaves stop producing chlorophyll.
tree and shrub species are genetically capable of taking the carbohydrates left
in the leaves and making them into anthocyanins. These are the red pigments responsible
for the reds, pinks, and purples in leaves. As the chlorophyll begins to break
down, the newly formed anthocyanins become apparent. Other plants are not genetically
capable of making the anthocyanins. When the chlorophyll breaks down in these
plants, the leaves reveal the more stable orange and yellow pigments (carotene
and xanthophyll). Brilliant oranges come from a mix of anthocyanins along with
the carotenes and xanthophylls. Trees that don't "perform" with remarkable
colors lose all their pigmentation at one time and usually over a short span.
are the weather conditions that favor the best fall color? Autumn weather that
favors good production of soluble carbohydrates in the leaves will lead to more
splendid fall coloring. Dry, sunny, and cool conditions but not lots of heavy
frost are best for bringing out the reds, oranges, and bright yellows. If plants
that are supposed to show spectacular color, don't... then their location or general
health may be the problem. Sunlight is generally needed for development of fall
color, especially the reds. If a plant is shaded, development of fall color will
be deficient. If the plant is experiencing stress, such as drought stress, fall
color may be lacking. A plant that is not cued into the advent of fall because
it's still growing vigorously due to heavy watering and fertilization late in
the growing season, may also lack brilliant color.
you remember pressing brightly colored leaves between sheets of waxed paper to
preserve their colors? It's one of those experiences of life that no one should
miss. Here's how you do it. Place autumn-colored leaves between two layers of
wax paper. Cover with an old towel or cloth rag. Press the fabric with a warm
iron, sealing the wax paper together with the leaf in between. Cut your leaves
out, leaving a narrow margin of wax paper around the leaf edge.
course that's the old-fashioned way of doing things. You can preserve fall leaves
in your microwave oven. Choose fresh leaves with the brightest colors. You don't
want fallen leaves that have already started to dry. Take separate leaves or small
twigs and place them in the oven on top of two pieces of paper toweling. Cover
them with one sheet of paper toweling.
the oven for 30 to 180 seconds. The drier the leaves, the less time they will
need. Observe caution, as you could start a fire in your microwave if they "cook"
too long. Be attentive. Leaves that curl after removal, have not been dried enough.
Leaves that scorch, have obviously been left in too long. Let the leaves dry for
a day or two and then finish the leaves with a sealant, such as an acrylic craft
may get even better results if you use the microwave and silica gel for drying.
Place a 1.25 inch layer of floral silica gel in the bottom of a cardboard box.
Place the leaves lying flat. Leaves should not touch and should be at least 1.25
inches away from the sides of the box. Cover the leaves with a 1.25-inch layer
of gel. Place the uncovered box in the microwave. You want the microwave to operate
at about 200 to 300 watts so if your microwave has 2-10 settings operate it at
level 4. If the oven only has three to four settings, it should be set at half.
If your oven has a high to defrost options, set the microwave on defrost. Estimated
drying time is 2.5 minutes if you're using a half pound of gel and about 5 minutes
if using two pounds of gel.
another way to preserve the leaves is to submerge them in a solution of glycerin
and water. Use a mixture of one part glycerin to two parts water. Place the mixture
in a flat pan, and totally submerge the leaves (in a single layer) in the liquid.
You'll have to weight them down to keep them submerged. In about two to six days
they should have absorbed the liquid and be soft and pliable. Remove them from
the pan and wipe off all the liquid with a soft cloth. Done correctly, the leaves
will remain soft and pliable indefinitely.
take some time with the children in your life and go out and collect some of the
treasures of fall. It's something they'll remember for the rest of their life...
I know I have.
for U.S. Regional Fall Foliage Update