Did you know that Fall is already here??? Tom and I just got back from Maine. Thankfully their temperatures don't apply to us who now live in Florida and it's hard to realize that it's even October here.
But it is still Fall here....some of our tree leaves will begin falling soon. Crape myrtles have already started losing their leaves but if they are planted near a street light they could be a little delayed. Some trees like the Winged and Drake Elms, Sycamores, River Birches, Sweet Gum, Chaste Tree, Dogwood and Redbud Tree have already begun their transition into fall.....in other words ..........they are now losing a few of their leaves.
Scientists have studied these fall changes for years and still don't know all the details but enough to shed some light on why it happens. Three things influence leaf change.....leaf pigments, length of night and weather is involved ......but slightly. As you know fall nights become longer and the amount of daylight for our trees is much less.
As with any artist.....a palette needs paint and Mother Nature's palette needs pigments also. She uses 3......which are chlorophyll that gives the leaves shades of green......Carotenoids which produce yellows, oranges and brown.....and Anthocyanins which add the reds and purple to her palette.
Both Chlorophyll and Carotenoids are in the leaf cells throughout the growing season while Anthocyanins are produced in the autumn in response to bright light and excess plant sugars in leaf cells. When fall comes and the length of our nights increase chlorophyll production slows down....then it stops and all the chlorophyll is destroyed. The carotenoids and anthocyanins that are left are then unmasked allowing them to show their fall color.
Temperatures and moisture do have a hand in fall color change and can affect chlorophyll production and can alter the colors to make them more or less intense.
I think Mother Nature let all those leaves fall for us to use in our gardens to help us prepare our planting areas......it's a free gift from her. And using them will make it harder for weeds to root down and much easier to pull up.