By Beth Burwinkel
Enquirer contributor

Autumn is a great time to admire trees and shrubs for their colorful leaves. If you come across a tree that you like, fall is also a great time for planting one in your yard.

We asked Kristopher Stone, director of the Boone County Arboretum, to tell us about some of the trees and shrubs that provide excellent fall color.

Question: What conditions bring out the best fall color?

Answer: To get optimal color, we need even rainfall, bright sunny days that create sugars in the leaves and cool crisp fall nights below 45 degrees. When the temperature drops at night, it traps sugars in the leaves, which intensifies fall color. Typically, the sunniest side of the tree will have the best red and orange leaves.

Peak color here usually occurs the third weekend in October. I think it's going to be a pretty good year for fall color. We've had plenty of rainfall and moderate temperatures.

Q: What are some great trees for fall color?

A: There are many trees for great fall color. We often recommend the ashes. The colors range from deep red, purple, maroon to orange, gold and yellow. Two good white ash cultivars are "Autumn Purple" and "Rose Hill." Good green ash cultivars are "Cimmaron," "Patmore" and "Marshalls Seedless."

Gingko has bright gold fall color. "Autumn Gold" provides great color, although any gingko cultivar will have good yellow fall color. Gingko leaves change color suddenly and they fall off the tree within one day.

Red maples are fail safe if you plant a named cultivar known for its fall color. "October Glory" is one.

Scarlet oak and white oak provide good maroon to purple fall color. Dogwoods are spring flowering with great red and purple fall color. Katsura is a medium sized tree with yellow and orange fall color. American smoketree has a rounded shape and is one of the most gorgeous trees in the fall. Its leaves are glowing red and orange.

Sourwood has brick-red color that starts early and lasts long. It needs acidic soil, rich organic soil and the same growing conditions as rhododendrons.

Sassafras has excellent fall color. Inner leaves will glow orange and outer leaves will be bright purple.

Zelkova leaves are red, orange and yellow. Sweetgum trees have deep red, purple, orange and yellow leaves. Birch, elm, fringetree, hickory, honey locust and linden turn shades of yellow and gold.

There are even deciduous conifers that provide fall color. Bald cypress needles turn a brown-rust color before they fall. European larch needles turn bright gold.

Q: What shrubs provide fall color?

A: Fothergilla has good orange-red color. The "Mount Airy" cultivar was developed in Cincinnati.

Virginia Sweetspire has great red fall color. All the sweetspire cultivars have good, bright red fall color. "Little Henry" is a more compact cultivar.

Viburnums are another great shrub. Typically, you get lots of reds and purples.

One of the best cultivars is "Winterthur." It gets to be more brick than fire-engine red. The whole shrub will just glow, and it holds color for a long time. It also has green glossy foliage all summer and a late summer bloom of white flowers.

European Cranberry Bush viburnum has orange and red fall color with bright red fruit.

Q: If a homeowner has a small yard, but wants a tree with good fall color, what would you recommend?

A: Flowering dogwoods are great. "Constellation" and "Stellar Pink" are two dogwoods with red leaves in the fall. Serviceberry has good fall color. Sourwood would be another great one for acidic soil. Sumac is a good tree for bright red fall color. It has a tendency to produce suckers. which need to be trimmed back.

Katsura is a nice tree; its leaves turn yellow-orange. Sassafras is a good choice, but you might need to go to a specialty nursery to find one.

Q: When should you plant trees?

A: We are entering a great time of the year to plant trees and shrubs. The best time is when they are dormant - from mid to late October to before Thanksgiving.

The soil temperature in the fall is warmer than spring. This gives the roots time to become established before winter sets in.

We don't recommend that you amend the soil when you are planting trees.

Dig an area as big as the container or root ball and half that size again.

Break up the soil clumps. Don't plant your tree any deeper than the original level of soil in the pot. It is best to plant an inch or two above the normal soil line to give the tree room to settle.

Check out arboretums

There's a lot to see in arboretums this time of year. Leaves explode with color. Often there's fruit to admire. When leaves fall, they reveal interesting bark and trunks.

"You'll find total surprises," says Rich Pearson, horticulturist at the Cox Arboretum near Dayton, Ohio. "You'll find fruit on trees you didn't realize had berries... I think fall is a kind of treasure hunt time of year."

Arboretums are a great place for looking at trees and shrubs. If you see something that catches your eye, odds are good that the tree will be labeled.

Here are some regional arboretums. Admission is free.

Boone County Arboretum, 9190 Camp Ernst Road, Union, has 1,800 trees and shrubs. The arboretum is integrated into a park with a walking trail and ball fields. This fall, the arboretum opened a children's garden. www.bcarboretum.org.

Mount Airy Arboretum, 5083 Colerain Ave, has many plant collections, including oak, dogwood and shrubs. Smaller trees are labeled. The arboretum is in the middle of a 1,400-acre forest, so you can expect lots of fall color. The arboretum is open dawn to dark daily. 541-2510

Spring Grove Cemetery and Arboretum, 4521 Spring Grove Ave., Winton Place, has 1,000 varieties of trees and shrubs, including 23 state champion and two national champion trees. The public is invited on a free autumn color walk tour led by a horticulturist 1 p.m. Sunday. To register: 681-7526. The arboretum is open 8 a.m. to 6 p.m. daily. 681-7526.

Cox Arboretum, 6733 Springboro Pike, near Dayton, has 60 acres of manicured grounds and 130 acres of woodlands. Prairie wildflowers bloom into fall. The arboretum's ornamental grass collection also is blooming. The arboretum is open 8 a.m. to dusk daily. (937) 434-9005.

The Stanley M. Rowe Arboretum, 4600 Muchmore Road, Indian Hill, has a variety of deciduous trees and shrubs as well as a large collection of conifers. Most plants are labeled. The arboretum is open dawn to dusk daily. 561-5151

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