Maple Leaf
FALL COLOR FOR THE LANDSCAPE
By Vicki Hammond
Horticulture Program Assistant
Why do leaves change to such beautiful colors?
The Cherokee Indians believed it came about when plants and animals were first created. The plants and animals were told to fast and stay awake for seven days to gain spirit power. Most made it through the first night, but as time went on, the various animals succumbed to sleep. Only the owl, panther, and two others were able to stay awake. As their reward, they were granted the ability to see at night. Of the plants, only the cedar, spruce, pine, holly, and laurel completed the task, and for this, they were allowed to keep their leaves throughout the year. This makes for interesting folklore, but it is not scientifically sound.
It is now understood that many factors influence the color, vibrancy, and timing of leaf changes such as sunlight, temperature, water, and soil ph. The amount of sunlight the plants intake during the season is known as the photoperiod. As the days grow shorter, the nights cooler, and the sun less intense, the break down of chlorophyll (the green pigment necessary for photosynthesis) in the leaf begins. Without chlorophyll the plant no longer takes in water and nutrients through the leaves, thus beginning its period of dormancy (decreased metabolism).
With the decrease in chlorophyll the other color pigments become dominate giving the beautiful yellows, oranges, reds, purples, and browns of autumn.
The yellow pigment, which manifests as yellow or yellow orange, is available from the onset of spring but is masked by the green in chlorophyll. The red and violet pigments are formed when sugar is trapped within the leaf as dormancy begins. The brown pigment is more species specific, such as with many types of oak leaves.
The weather is a main factor in helping to determine the vibrancy of color. The best color display occurs when there has been an abundance of rain and sunshine throughout the summer, followed by sunny days and cool nights in the fall. This is especially true for red and violet tones as more sugar becomes trapped during the sunny days of fall. The availability of iron found in acidic soils is also a key influence, as is drier well-drained soil.
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Plant |
Name |
Color |
Comments: |
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Type |
Common |
Botanical |
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Trees |
Japanese Stewartia |
Stewartia pseudocamellia |
Yellow, red, dark reddish purple |
Interesting bark; 30’ - 40’ H – oval shape |
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Downy Serviceberry |
Amelanchier arborea |
Yellow, apricot |
15’ – 25 ‘ rounded Native; attracts birds |
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Autumn Purple |
Fraxinus Americana |
Yellow, red, purple |
50’ – 80’ H Native |
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Persian Parrotia |
Parrotia persica |
Yellow, orange, red |
20’ – 40’ H x 15’ -30’ W |
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Shrubs |
Blackhaw Viburnum |
Viburnum prunifolium |
Red to red bronze |
12’ – 15’ H Native |
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Mapleleaf Viburnum |
Viburnum acerifolium |
Fluorescent rose to grape-juice purple |
4’ – 6’ H/W Shade tolerant Shiny black fruit |
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Fothergilla |
Fothergilla gardenia, F. major |
Yellow, orange, scarlet |
2’ x 3’ Dwarf var. 6’ x 10’ Large var. Native |
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Oakleaf Hydrangea |
Hydrangea quercifolia |
Red, orange, purple |
4’ – 10’ H |
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Vines |
Boston Ivy |
Parthenocissus tricuspidata |
Red and scarlet |
Prune to keep in bounds |
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Virginia Creeper |
Parthenocissus quinquefolia |
Red |
Climbs trees but will not harm them |
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Fall foliage on Rolvaag Library window
Information Sources:
Photo Credits:
(http://www.stolaf.edu/offices/publicrelations/photos/imagelibrary/fall2.jpg)
Additional Plant Sources:
10/05