Why do Leaves Change Colors in the Fall?

Fall color at Devil's Lake State Park

I went on a hike at Devil's Lake State Park the other day as a stress reliever, but I also knew that it was the peak time for fall colors in central Wisconsin... and boy was there a colorful palette across the Baraboo hills! It was one of the most beautiful drives and hike I've ever taken. Many of you probably wonder driving by on a autumn day why would trees change such striking colors? Amazingly, scientists still cannot fully answer that question, but some of the factors have to do with weather throughout the growing season and day length.

Red Maple leaves

As you know, nearly all plants contain the pigment Chlorophyll. This is what makes the leafs green and helps the plant take in energy from the sun to aid in photosynthesis which is how the plant makes food (with the added components of water and oxygen in the equation too). with the coming of fall, the length if nights becomes longer, and this triggers a biochemical change within the leaves. This is a sign for the tree to seize photosynthesis, stop producing and destroys the Chlorophyll in the leaves. As a result, other pigments in the leaves are revealed like Anthocyanin (gives the leaves a deep red color) and Carotenoids (gives the orange and yellow colors). After that, the tree goes through senescence or detaching of the petiole (leaf stalk) from the node.
Weather also plays a role. The key ingredient is warm, sunny days and crisp, but not freezing nights. This mixture specifically produces the striking reds in leaves. Also, intense colors also need a warm spring, normal summer, and adequate moisture throughout the growing season. This year, Wisconsin had a warm spring, wet and warm summer, and cool nights in the fall... the perfect combination for fall colors! And now you've learned something today.

Smooth Sumac leaflets

What's astonishes me is that the tree knows. Think about it, here is an organism that has no brain or central nervous system, and yet it goes through this whole thing because it "knows" that winter is coming... this is a plant folks. It's events like this that made me realize that everything didn't happen by chance or accident. Something to think about when you're zoning out at class or work. Anyway, you can now enjoy the fall colors even more this autumn!

Verse of the day: "Above all else, guard your heart, for it is the wellspring of life." - Proverbs 4:23

Witch Hazel: The Procrastinating Shrub

Witch Hazel flowers

With the arrival of October, plants are preparing for the long winter ahead. Shades of reds, oranges, yellows, and browns color the landscape with plants going through senescence, and vivid and unique fruits are dispersed through every way in the book. Yet, the crisp air and shortening days triggers one shrub to flower? Yes I said that, even later then the goldenrods and asters.
The Common Witch Hazel, or Hamamelis virginiana, is a understory shrub or small tree found in rich forests east of the Mississippi. It is also a procrastinator, unfurling it's ribbon-like yellow petals after the first frost, and can continue blooming even into December! But why would a shrub want to bloom at a time when pollinators are dying out or going dormant for the season?
Ironically, there are still small flies, midges, and gnats out flying around in search of food. So by making itself the only food source out there for that time of the year, the flowers are bound to get pollinated. Witch Hazel has a few tricks up it's sleeve for dealing with the cold. The flowers are only active during a warm spell when insects wake up and attracts them using a strong fragrance for the few buzzing around. Once pollination is complete, the fruit doesn't develop until the following spring. Pretty nifty huh?
The hard capsules ripen throughout the spring and summer. Once they are ripen in the fall, the pressure from the capsules opening shoots the seeds out as much as 30 feet! This is a good trick in the plant world because the "mother plant" doesn't want competition from it's children. Extract from the bark and leaves are used as lotions, hemorrhoid treatment, and treatment for acne. The name was from the fact that the branches were  supposedly the best for "witching" or dowsing, a trick used to find ground water.
I'm a student in horticulture, so trust me on this one. This is a great landscaping shrub for your yard. It adds interesting yellow flowers late in the season, and has great fall color. It likes shade to part sun, but if you want a lot of flowers, full sun is recommended. The only downside is that, because it's a woodland plant, it will get sunburned. This is shown through browning leaf edges and discoloration of the leaves. Otherwise, this procrastinator is one of my favorite shrubs for the home garden.

Verse of the day: "but God shows his love for us in that while we were still sinners, Christ died for us" Romans 5:8. It's never too late to know Christ as your personal savior, just like it's never too late for the Witch Hazel to bloom in the coming winter.