You may often hear people say Labor Day is traditional end of summer, and, according to the calendar, fall will officially start at the fall equinox on Sept. 23. In south Louisiana, however, the summer season extends a good bit longer.

You might begin to notice more vigor in your warm-season bedding plants in September, says LSU AgCenter horticulturist Dan Gill.

Even heat-tolerant flowers don’t always look their best in August. But shorter days mean fewer hours of intense heat, even though the daytime highs may stay about the same, and plants begin to experience less stress.

You may be able to revive some of your summer bedding plants and flowers that have grown tall and leggy over the long growing season, Gill says. This generally involves cutting plants back about one-third to one-half their height.

In addition to cutting back, groom the plants to remove dead flowers and unattractive foliage. If plants are leaning or have fallen over, prop them up or stake them so they will stand upright.

If you have an area where the summer flowers have finished and been removed, it’s still too hot to plant most cool-season bedding plants, Gill says. Mulch the area now and wait until the more reliably cooler weather of October or November to plant pansies, violas, dianthus and snapdragons.

If you haven’t done so, cut back your repeat-flowering rose bushes, Gill advises.

But don’t prune old-fashioned climbers, ramblers, Lady Banks roses and some bush roses that bloom heavily in spring to early summer and then stop. They will bloom next year on the growth they made this summer, so leave them alone.

Spring-flowering bulbs, such as tulips and daffodils, generally become available at nurseries this month. But don’t be in a hurry to plant them, Gill says. You may buy them while the selection is good, but wait to plant bulbs into the garden from mid-October through early December.

The chrysanthemum is often considered the floral symbol of fall, and you will begin to see them available for sale this month as well. But if you wait until reliably cooler temperatures to purchase chrysanthemums, the flowers will last longer in the garden and provide a longer colorful display.

Got a gardening question? Write to GardenNews@agcenter.lsu.edu.