Backyard Wisdom

Trees for Fall Color--Guest Blogger Danny Cain

In the most recent blog entry here at Backyard Wisdom, we welcomed Danny Cain. He is the county Extension coordinator in Walker County, which is in northwest Alabama. Two of Danny’s particular work areas include forestry and home grounds.

In today’s blog post, he offers his thoughts on trees that are both suitable to Alabama and offer good fall color.

Trees for Fall Color

By the way, speaking of brilliant fall color, if you are looking for a couple great looking trees that offer some of the best fall color that Alabama has to offer try planting a Chinese pistache tree (not to be confused with the tree that produces pistachio nuts). It is a great medium-sized tree that will add color to any Walker County landscape and is even a good urban tree for high use areas in our urban landscapes.

The flowers of the Chinese pistache tree are very inconspicuous at best, but the long clusters of purple-red fruit can be very attractive. It has a medium texture and its compound leaves are usually a deep dark green during the summer. But that’s not the best part. The best part is its fall color in brilliant red-orange that will rival any sugar maple in the country! Another great thing about Chinese pistache trees is that they are extremely tough and will adapt to a wide variety of soil conditions. They are also very drought tolerant after they get established.

The Chinese pistache is an “ugly duckling” tree as a juvenile, often having a crooked trunk and unruly branches. After about three to five years; however, it begins to mature into an arching tree with an oval-rounded canopy reaching a height of 30 to 50 feet when it is full grown. Just trust me on this one, forget about the name, overlook the three to five years when the tree doesn’t look so good but go ahead and plant one or two Chinese pistache trees and look forward (a few years down the road) to some of the best fall tree color you have ever seen.

A ginkgo tree is another example of a tree that will work in local landscapes that also has great fall color—in this case yellow. It also has very interesting fan shaped foliage during the summer time. Have patience if you decide to plant ginkgo as it is not necessarily the fastest growing tree around to say the least. One additional thing, if you decide to use ginkgo make sure that you purchase certified male plants to avoid problems down the road with fruit that will drop off the tree and create odor problems. Certified male ginkgo trees will produce no fruit.

Here are a few other trees (some of them are natives as well) that you may want to consider for fall color :

Japanese or red maple (red)

downy serviceberry (yellow or orange)

shagbark hickory (yellow)

sourwood (red)

shining sumac (brilliant red)

flowering dogwood (maroon/burgundy)

or perhaps even black gum (red).

The Department of Forestry at Virginia Tech University has an excellent web page that lists a number of trees with links to photos of their fall foliage.

There is also a time lapse photography sequence of a stand of trees changing color at the Virginia Tech Web site.

Fall Color in Alabama--Guest Blogger: Danny Cain

This week, Backyard Wisdom welcomes its first guest blogger, Danny Cain. Danny is both a friend and a colleague. He is the county Extension coordinator in Walker County, which is in northwest Alabama.

Fall Color in Alabama

I recently had the opportunity to observe some of the best natural scenery that I have ever seen while riding with a couple county agent buddies of mine in the hill country between Lake Guntersville and Monte Sano State Park. The sun was shining down through the valleys and almost seemed to make the maple trees, which are numerous in North Alabama, glow red. To top it off we were treated to a rainbow that seemed to reach from the mountaintops to the maple trees. People travel near and far to see such scenery, and we have it right here in Alabama. I have always said that we live in one of the most beautiful states. Anyway, that experience got me to thinking a little bit about fall colors and where they come from.

Here is a little bit of fun fall trivia for your enjoyment. Do you know what a ripening banana has in common with fall leaves? The green color in bananas when you buy them at the grocery store is actually chlorophyll, the same pigment that gives leaves their green color. As bananas ripen, the chlorophyll breaks down and disappears allowing the yellow color, which has been there all along, to show through. The potential for the yellows and oranges of fall leaves have likewise been there all summer long and have been covered up by the green chlorophyll.

The cool mornings and changing of leaf color from green to reds, yellows, and oranges can only mean that fall has arrived. Another reminder is the fact that there is now a constant supply of freshly dropped leaves on the ground. The tremendous variety and mixing of the reds, yellows, orange, and even purples for some plant species mixed with the greenery of our pines really makes a wonderful display that comes and goes fairly quickly in our part of the country.

Now you know that the leaves do not actually “change” colors by magic in response to frost but rather because of chemical processes in the plant that cause chlorophyll (and the green color) to break down. Photosynthesis, the food-making process in the plant, takes place in the green, chlorophyll-containing leaves.

In addition to chlorophyll, leaves contain yellow, orange, and often other color pigments such as carotene (the pigment that gives carrots their orange color). For most of the year, the yellows and oranges are hidden or have not been expressed ,but as daylight hours shorten and temperatures drop….you guessed it, we get the first hint of fall colors.

While all this is going on inside the plant, other changes are going on as well. Other chemical changes cause yellow or red or even purple pigments to form. This is what gives plants such as dogwoods, sumacs, sweet gums, and other trees their red to purple fall colors. Other trees have colors that easily distinguish them as well. Sugar maples take on a fiery orange color, hickories show only yellow colors, while oaks are primarily reddish brown to brown.

Warm sunny days with nighttime temperatures below 45 degrees tend to raise the level of red coloration. The cool nighttime temperatures trap the sugars produced during the daytime inside the leaves. Common trees with red fall color include red and silver maples, flowering dogwoods, sweet gums, black gums, red oaks, and scarlet oaks.

The interesting thing about fall color is that it can vary from tree to tree because of things such as genetics or physical location. The color can even vary on the same tree. For example, leaves directly exposed to the sun may turn brilliant red while those on the shady side of the tree may turn yellow or may even simply turn brown and shed off. Trees of the same species and the same location can vary in fall color from year to year depending upon weather conditions.

As the leaves “change” color, other things are happening to them. At the base of the leaf where it attaches to the branch or limb, the leaf gradually separates from the tree, and the result is the all too familiar fall leaf drop. At the same time, scar tissue forms on the twig to seal the scar left where the leaf was attached. And you thought that all leaves did in fall was simply change colors and fall!

Most Alabama Lawns Don’t Need Fall Fertilizer

You have seen the bags stacked in garden centers across the state. Most often it’s labeled as a fertilizer to “winterize” your lawns. But winterizing is a bad idea for most of the lawns in the state.

Dr. David Han, a regular guest on Backyard Wisdom and a turf specialist with the Alabama Cooperatives Extension System, says these winterizing fertilizer formulations are not recommended for the majority of Alabama lawns.

He says that winterizer is not for bermuda, centipede, zoysia, and St. Augustine grasses. These are all warm-season grasses.

Han notes that the practice of winterizing lawns is strictly for cool-season grasses such as those found in lawns from North Alabama northward.

Fescues and bluegrasses grow in cool weather and remain green through the winter. These perennial, cool-season grasses rarely survive the hot summers of the Deep South but they thrive in the cool summers of New England and the upper Midwest. To maintain these grasses through the harsh winters of those areas, fall fertilization is recommended.

You could actually harm your warm-season lawn by attempting to winterize it with afall fertilization.

Warm-season grasses go dormant or semi-dormant during winter. They produce very little if any growth from October through April in central Alabama. A fall application of nitrogen may actually stimulate them into producing succulent growth, which will only set the grass up for severe damage when a frost or freeze does occur.

Auburn University’s Soil Testing Lab recommendations for these grasses state clearly that nitrogen should be applied up to September and no later.
Dr. Charlie Mitchell, another regular contributor to Backyard Wisdom and an Extension soil scientist says later applications are risky.

He says that adding phosphorus or potassium to warm-season grasses in the fall is a wasted effort. Growth is slowing down dramatically. Adding more nutrients in the fall won’t make the grass healthier.

Han and Mitchell both say there are exceptions to every rule. They say that some lawns in north Alabama that are planted in cool-season grasses may be that exception.

Han says because fescue, bluegrass, bentgrass and overseeded ryegrass grow rapidly during the cool days of autumn, these grasses can benefit from a fall fertilizer containing nitrogen.

Mitchell adds the Auburn University Soil Testing Laboratory recommends a fall nitrogen application for these grasses.

Division Time in the Garden

The weather has finally moderated here in central Alabama, and it’s actually pleasant to work out in the garden. I have a number of chores ahead of me including more weeding than I really want to consider.

But I also have one chore that I actually look forward to tackling. That’s dividing perennials. There is something very satisfying about taking one large plant and dividing it into two or more plants. Sometimes those new plants all go into my garden, but I also like to share my bounty with friends and family.

There are several good reasons to take time and divide your perennials. First, you can increase the number of plants you have. Dividing can help you both rejuvenate plants as well control their size. Some perennials can spread fairly quickly and outgrow their original planting areas. Yellow flag iris (Iris pseudacorus) planted in a wet or boggy area seem to expand overnight. I had to divide these yearly until I finally wised up and planted them in drier parts of the yard where they expand much slower.

Dividing rejuvenates some perennials and stimulates better blooming. Other perennials tend to spread out from their original center leaving bare spots. Dividing these types lets you fill open areas in your beds while increasing the number of plants as well.

Many of the perennials in my garden can be divided either in the spring or early fall. I prefer the fall because I think it gives plants plenty of time to establish new roots and settle into their new spots before the blistering heat of Alabama summers sets in.

Check out this publication about perennials from the Alabama Cooperative Extension System. The folks over at Clemson also have this excellent fact sheet about dividing perennials.