DO trees have the same FALL colors every year? Are Yellow trees always yellow, Red trees always Yellow?

Answer 1

Basically, but some trees change the leaf color over the course of the fall. Ashes start out yellow, but can turn purple right before they drop if they have certain minerals in the soil. But they'll always be yellow, or yellow and purple, they can't change to red or orange. Their genetics only allow them to make certain pigments, and those pigments determine what colors the leaves can be.

Sometimes environmental facors can influence the final result, like the soil determining if the ash leaves can turn purple. Another example is red maple, which should turn to red, but the color only develops if the leaf is exposed to the sun. If it's shaded, it turns yellow because a reaction is needed between the pigment and sunlight for the red color. I once found a maple tree with some leaved stuck together by some kind of caterpillar. The leaf on top was all red, but the one underneath was part red and part yellow from where the leaf on top overlapped it. You could see every tooth from the top leaf. I've heard that as an experiment you could tape a design or message on a red maple with duct tape in the fall before the leaves change, and when the rest of the leaf is red, you can collect the leaf and pull the tape of to see the design message.

If you want a tree with lots of colors in a single tree, find a sugar maple or sweet gum because these will have every color from yellow to orange to red and the gum will also turn to dark purple.

I should also mention that leaf color will depend on sun and soil moisture. This year there's a weird fall in the northeast and the leaves didn't change their color or drop off at the regular time. Most were killed by frost so a lot just went from green to brown maybe with some changing to yellow. In years where there's a drought or its always cloudy, you won't get as good of colors as in years where there's a good mix of sunny and rainy days.

Answer 2

The below explanation is directly from the website sited. It appears that the colors (if a tree turns yellow or red for instance) is fairly consistent, though the brilliance of the color red can vary depending on the weather that year.

"Leaf color comes from pigments. Pigments are natural substances produced by leaf cells. The three pigments that color leaves are:


chlorophyll (green)
carotenoid (yellow, orange, and brown)
anthocyanins (red)

Chlorophyll and carotenoid are in leaf cells all the time during the growing season. But the chlorophyll covers the carotenoid -- that's why summer leaves are green, not yellow or orange. Most anthocyanins are produced only in autumn, and only under certain conditions. Not all trees can make anthocyanins.

When a number of warm, sunny autumn days and cool but not freezing nights come one after the other, it's going to be a good year for reds. In the daytime, the leaves can produce lots of sugar, but the cool night temperatures prevent the sugar sap from flowing through the leaf veins and down into the branches and trunk. Anthocyanins to the rescue! Researchers have found out that anthocyanins are produced as a form of protection. They allow the plant to recover nutrients in the leaves before they fall off. This helps make sure that the tree will be ready for the next growing season. Anthocyanins give leaves the bright, brilliant shades of red, purple and crimson.

The yellow, gold and orange colors created by carotenoid remain fairly constant from year to year. That's because carotenoid are always present in leaves, and the amount does not change in response to weather."