“Groundwork” column for Sept. 30

With fall approaching and football season getting into full swing, garden mums become one of the popular plants available for home landscapes.

Garden mums fill the gap between the end of the warm-season bedding plant period and the true beginning of the time for cool-season bedding plants.

This hardy, long-lived perennial generally blooms from October to December when grown in the garden. Chrysanthemums are triggered to bloom only when the nights are long enough.

During the summer, when days are long and nights are short, chrysanthemums in the garden grow vegetatively. As the period of nighttime darkness increases in late summer and early fall, flower bud initiation occurs. This generally takes place here in August and September.

The best chrysanthemums for planting in the landscape are garden mums. These mums are bred and selected for growing in the garden. They are short, bushy plants about 12 inches to 18 inches tall that literally cover themselves with clusters of small 1½-inch flowers in virtually every color except blue.

Two-toned bicolor flowers have been recently introduced. Garden mums are available now at nurseries and garden centers in 4-inch, 6-inch and gallon containers.

Select plants with mostly closed buds and healthy foliage when purchasing garden mums. Plants already in full bloom will not be attractive as long.

Avoid plants with flowers that have already begun to fade or those that have broken branches and yellow foliage.

Garden mums perform well in full to partial sun — six to eight hours of direct sun is ideal.

Be sure to properly prepare a landscape bed by improving aeration and internal drainage with additions of pine bark or some other form of organic matter. Provide up to 2 feet between plants. Close spacing results in leggy, upright growth.

After planting, apply about 3 pounds of a slow-release fertilizer per 100 square feet of bed area. Broadcast the fertilizer uniformly over the entire bed and lightly water it in. Mulch with a 1-inch layer of pine bark, shredded pine straw or a similar material.

After they finish flowering, garden mums should be cut back about one-quarter their height.

In late January or early February cut them back to about 3 inches from the ground.

New growth usually begins in February or March — when new shoots appear at the base of the old stem stubs.

When you see the new shoots, it is a good idea to dig up the whole clump, divide it into two to four sections and replant those where you want them to grow.

Space them about 12 to 18 inches apart. When doing this, discard the brown, woody middle of the plant and plant only the vigorous shoots from around the outside.

Dividing the mums annually makes them strong and vigorous and allows you to keep control over them.

Allen Owings, LSU AgCenter horticulturist, offers these tips to keep your mums looking their best in your landscape. Because fall typically is dry in Louisiana, be aware that lack of water on garden mums delays flowering, slows or stops growth, and increases susceptibility to pest pressures. Proper moisture leads to a successful garden mum crop.

It is also imperative to avoid overhead irrigation and water only the bed area or around the dripline of each plant. Do not soak garden mums at the base of each plant. This will result in stem rot problems.

You can maintain garden mums as perennial plants if you follow these practices:

• Keep soil moist (not wet) through winter.
• Prune lightly several times between late winter and mid-spring next year.
• Continue mulching.
• Maintain good insect and disease management.
• Fertilize lightly in spring with a slow-release fertilizer.

Basic gardening

The East Baton Rouge Parish Master Gardeners is offering a Basic Gardening Series at the East Baton Rouge Parish Jones Creek Regional Branch Library from 6:30 p.m. to 8:30 p.m. Thursday and Oct. 11. To register for the free programs, call [phone].

Two topics will be discussed each evening. Topics to be covered and the schedule are:

• Thursday: “Cool Weather — What to Plant?” — Learn what plants are best for the cool season in Baton Rouge and what’s new. “Composting to Enrich Your Garden” — Make your soil better and begin now.
• Oct. 11: “Soil and Bed Preparation” — Learn how to create a flower or garden bed and prepare the soil to accept seeds or transplants. “Growing Roses” — Learn the basics and finer points of growing roses.

Hilltop’s plant sale

LSU Hilltop Arboretum’s annual fall plant sale, PlantFest! 2012, will open its gates from 9 a.m. to 4 p.m. Saturday and noon to 4 p.m. Oct. 7 at 11855 Highland Road.

You will be treated to a buffet of plants — trees, shrubs, perennials, vines, ferns, fruits, gingers, camellias, ornamental grasses, and more that run the gamut from native and traditional plants to eclectic newcomers.

More than 5,000 plants will be assembled representing 600 different species.

A listing of all the plants being offered at the sale is posted on the Hilltop website, http://www.lsu.edu/hilltop.

To put even more “fun” in the “Fest!” the Hilltop Gift Shop will be joined by specialty plant and craft vendors offering books, garden tools, ironwork, woodcraft and just about anything you might need for the birds.

Got a gardening question? Write to Bob Souvestre, horticulturist with the LSU AgCenter, at Burden Center, 4560 Essen Lane, Baton Rouge, LA 70809, or email to [e-mail], or call Master Gardeners at [phone].