Garden Talk: Tree Care

Air Date:
Heard On The Larry Meiller Show

Trees need care just like other plants in the yard and garden. Larry Meiller finds out about pruning, watering and fertilizing trees, plus a new local wood utilization project.

Featured in this Show

  • The Science Of Autumn Colors, Explained

    Trees have always been a stunning part of the Wisconsin landscape— something that’s especially true when the leaves turn in Autumn. While the changing color of leaves might seem like magic, it’s actually a matter of chemistry and biology.

    “What we’re seeing this time of year are some of the pigments that are in those leaves all year-round that are being made visible by the reduction and elimination of chlorophyll,” said Fred Clark, a career forester and arborist who is also the founder of Baraboo Woodworks.

    Chlorophyll is a pigment that’s a vital part of the process of photosynthesis. According to Clark, it’s “what produces the sugars that become the food source for the tree, and gives the leaves their green color.”

    Clark said in the autumn, trees begin to get a signal from the surrounding environment to slow down chlorophyll production. He said that for some species, the signal is the shortening of days as the end of the year approaches. For other species, the trigger may be falling temperatures or the first frost of the season.

    When chlorophyll production declines, the green color in the leaves fades and those brilliant reds, yellows, oranges and browns become visible.

    Clark said that different trees’ leaves turn different colors, due to the varying chemical make-ups of leaves from species to species. For example, leaves that turn orange or yellow contain carotenoid pigments, while those that turn red contain anthocyanins.

    Since the chlorophyll is a food source, it also means that as it declines, the leaves die and fall off of the trees. But before they do, tourists and residents alike enjoy the show.

Episode Credits

  • Larry Meiller Host
  • Judith Siers-Poisson Producer
  • Fred Clark Guest

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