September great for gardening, education
Gardening
Keith Hansen Smith County Horticulturist

September is always a month of transitions.

Kids are back in school, sports activities are gearing up, and summer's heat gives way to more moderate temperatures and more frequent rainfall (usually).

That's good for gardeners and gardening.

Fall gardening educational activities also pick up at this time of year.

The Smith County Master Gardeners resume the "First Tuesday in the Garden" workshops in the IDEA Garden.

The IDEA Garden is in the southeast corner of the Tyler Rose Garden.

Trees and Shrubs

Despite the welcome, drought-breaking rains of this spring and summer, our soils are starting to dry out again. Frequently check the soil with your fingers around newly planted trees and shrubs to make sure the root ball and soil are getting enough water.

At the same time, take care to not keep the soil soaking wet.

Just because it's hot doesn't automatically mean the soil is dry 3 or 4 inches deep. Check it out that deep to be sure.

Shallow-rooted plants like azaleas, Japanese hollies and dogwoods are especially prone to drought stress.

In the absence of significant rainfall in the next week or two, consider deep watering your shade trees and other woody plants.

Upper soil moisture is drying out again, and our plants don't need to experience any more stress after the drought of the last two years and saturated soils earlier this year.

Landscape Plants

! There are many perennial plants that bloom in the fall, including chrysanthemums, Mexican mint marigold, ornamental grasses, rain lilies, spider lilies, fall asters, Mexican bush salvia (Salvia leucantha), sedums, to name a few.

Add some of these to keep your garden continuously blooming and interesting.

! There are many early spring blooming plants that should be either started from seed now or divided during the fall.

Most wildflowers should be started from seed in late August or September.

They will germinate and grow as low, unnoticed rosettes during fall and winter, but will quickly expand in spring to put on their show.

The later you wait to sow wildflowers, the smaller the plants and blooming display next spring.

Do not use a preemergent herbicide where you are planning on growing wildflowers.

! Divide crowded perennials like iris, daylilies, shasta daisies, liriope, mondograss, perennial phlox, other springblooming perennials and groundcover plants.

Throw out older crowns and replant healthy divisions, giving them room to grow and spread.

! Allow woody plants to finish the summer growth cycle in a normal manner.

Never encourage growth with heavy applications of fertilizer or excessive pruning at this time. New growth can be easily injured by an early hard freeze.

! If you're contemplating moving a small tree or shrub this winter, prune the roots now so it can produce a more dense, compact root system over the next several months, increasing the chances of success by reducing transplant shock.

Roses

Lightly prune roses in early September and lightly fertilize them for a beautiful, last flush of color in October.

This what they'll be doing at the Rose Garden in early September in anticipation of the Texas Rose Festival this October.

Evening thunderstorms, while bringing welcome rain to the landscape, also help promote rose black spot, a leaf fungal disease that can cause leaves to drop. Black spot is much easier to prevent with a fungicide than trying to stop the disease once it gets going.

Vegetables

The following can be plant in September for delicious and nutritious fall and winter harvests - beets, broccoli (plants), Brussels sprouts, cabbage, carrots, cauliflower (plants), Swiss chard, collards, kale, garlic, lettuce, mustard, parsley, English peas, radish, spinach and turnips.

Lawns

If your lawn had significant weed problems in late winter and early spring, or if the turf is somewhat thin, then an application of a pre-emergent herbicide (weed preventer) in early September can significantly reduce your weed problem this winter and next spring.

Some of the most common winter weeds that can be controlled with a pre-emergent herbicide include henbit, chickweed, lawn burweed and annual bluegrass.

Water the lawn with about a half-inch of water immediately or at least within a day or two after applying the herbicide.

You need to water it in as soon as possible so that sunlight doesn't get a chance to start breaking it down.

Before buying pre-emergent herbicide, read the label carefully to determine if the material is appropriate for the type of grass and weeds you will be treating.

Later this month fertilize lawns to strengthen and prepare them for winter dormancy.