Plant answer man

Enjoying the four seasons in this part of the country is easy when you have a 1,700-acre outdoor museum with 4,057 kinds of trees, shrubs and other plants as a neighbor. With lots of fall activities for everyone in the family, you might consider several visits to the Morton Arboretum in Lisle.

Keeping everyone clued in on what's hot in fall colors, plant records manager Ed Hedborn reports his color findings weekly on the Bloom 'n' Color hotline at (630) 719-7955. The botanist also teaches a class in fall colors as well as arboretum college classes, and helps with its art certificate program. With such expert help by phone and in this column, the beauty of autumn is at your fingertips.

Q. What does your job as plant records manager require?

A. I am in charge of making sure the inventories are taken and keeping track of all our plant life history information. My office is where anyone would start to find the answer on any question on any of our plants that we have ever grown since 1922.

Q. How does weather enhance or change fall colors each year?

A. Weather is the most important factor in fall color development after the genetics of the plant. In the fall, the onset of color develops with shortening daylight. You get the best color with bright sunny warm days, cool nights, adequate moisture for the year, a good growing site and a healthy plant.

Q. How does a cool night affect colors?

A. Cool nights tend to build up sugars and those convert into the pigments that give us the bright colors. During the summer, the green you see is chlorophyll, which is the chemical engine that captures sunlight to convert into energy that the plant can use.

Another pigment in the leaf are the carotenes that give us the yellow and orange pigments that are there all the time but masked by the chlorophyll in summer. As the daylight shortens, the chlorophyll fades away and the yellows are unmasked.

The red pigments, the anthocyanins, are made by certain kinds of plants in the fall, such as the sugar maple, red maples or red oaks. In optimal conditions, the red pigment is enough to completely mask the yellows that are there. In another year, the conditions may not be as good and it may make only a little bit of the red pigment.

When it mixes with the yellow pigments you get an orange color. In still another year, you may only have a yellow color.

Q. What is the sequence of plant color changes in this region?

A. In mid- to late-September, the sumacs change to a brilliant red first. Then you'll start to get the green ash, redbuds and burr oaks.

In the first week of October, the hickories, honey locusts and white ash start. In the second and third week of October, the sugar maples come with a big show of color.

In late October, the native oaks such as white oaks start. Then at that time and on into November, you get some of the European plants such as the Norway maple and Bradford pears. Plants in open areas change before those in shady areas and those in flood plains are about 10 days later. With cool, cloudy weather and not a lot of wind, the color can extend into November.

Q. If you were a new homeowner with a blank yard, what three trees would you start with?

A. I would probably put in a burr oak to give yellow and brown, a white oak to give purple and a black maple, which is a close relative to the sugar maple, to give yellow, orange or red depending on the year. They all have different bark textures, patterns and colors to enrich your viewing all through the winter season.

Take time to enjoy the wide variety of tree colors even in the winter. There is a lot of beauty in all seasons.

Q. How can people identify the different trees?

A. All the plants in our collection have an accession number. There is an aluminum label on the south side of the plant that is convenient to read. It will have how we got the plant, its grid location on our grounds, the scientific and common name of the plant. Jot down that information and our librarians at our Sterling Morton Library will help find a nursery where you can buy the plant.

Q. When walking the arboretum's Scarecrow Trail, what should people watch for?

A. The trail is a .6-mile asphalt hard surface path right outside our visitor's center. Surrounding Meadow Lake are colorful native plants. Some trees along the trail include pin and scarlet oaks, European larches and a couple paper-bark maples from East Asia.

Q. A signature piece at the arboretum's fall festival is its taffy apples. Will you have one?

A. They are very good. I probably will manage to make one disappear.

-- Joan Broz

If you go

What: Morton Arboretum Fall Color Festival

When: Festival activities 11 a.m. to 4 p.m. every weekend through October and Oct. 8, 11 a.m. to 2 p.m. Wednesdays; Scarecrow Trail open 8 a.m. to 6 p.m. daily, vote for your favorite scarecrow designed by local Girl Scout troops

Hours: Arboretum open 7 a.m. to sunset daily

Where: 4100 Route 53, Lisle

Admission: $9 for adults, $8 ages 65 and older, $6 for ages 3 to 17; discounts on Wednesdays

Info: (630) 968-0074 or mortonarb.org