Preparing the garden for autumn planting

Texas Sage (S. coccinea) in full bloom (Contributed photos)

After weeks of hot dry weather, Nicholas teased us with the hope of rain. Instead, the storm danced up the coastline giving us a whole three tenths – yippee! Sadly, the Houston area received too much rain, and hurricane season isn’t over yet.

While we are still vigilant, keeping an eye on the gulf, the second season has arrived. Autumn is that magical time when the garden puts on a vivid display of color before winter. As we wait for that first cold front and relief from the unrelenting heat of summer, it’s time to get the garden ready for the splendor of the autumn season.

It’s my time of the year – Halloween carnivals, little witches and goblins ringing the doorbell for treats, football, sweater weather and the anniversary of my first date with the husband. I love pumpkins, autumn leaves and the rich purples and bronzes of chrysanthemums. 

The long fall growing season in South Texas is the perfect time to add new perennials, shrubs and trees to the garden. September is usually one of our wettest months. Trees planted in the fall have a better chance to flourish. Warm soil and milder temperatures make it possible for plants to quickly become established. Over the fall and winter the plant root systems continue to grow giving them an edge when the unrelenting heat of summer returns.

When considering adding a tree to your landscape, be sure to use the four rights. Plant the right tree, in the right place, in the right way, at the right time of the year. This simple technique should be used when adding any plant to the garden. By using this system of planting your odds of success will increase, allowing plants the ability to adapt to the landscape.

Uri was an anomaly; usually we have a long growing season in the fall followed by a mild winter. This allows us to enjoy a garden filled with color. While it’s still too hot for pansies and violas, there are plenty of annuals and perennials that can be planted now to add color to your fall garden. 

Many spring blooming perennials will bloom again with more intense color when the weather cools. Salvias, members of the mint family, are dependable fall bloomers. Mexican bush sage (S. leucantha) is a vigorous upright plant with grayish green leaves. The bloom spikes are covered with white flowers with velvety purple calyxes. To keep plant size in check and renew flowering stems, cut back close to ground before spring growth begins and again in late summer for the fall display.

One of my favorite members of the sage family is Lyre-leaf Sage (S. lyrata), a native wildflower to the southeast which forms low growing rosettes. The charming little plant has lyre-shaped leaves with distinctive reddish purple markings. Bloom spikes of lavender-blue flowers appear in winter and spring. Lyre-leaf’s low growing habit makes it the perfect plant to grow in the cracks of native stone walkways.

Autumn Sage (S. greggii) is another dependable salvia to add to the garden. A native to southwestern Texas and north-central Mexico, it blooms from summer through the fall. 

Mealy cup Sage (S. farinaccea), another wildflower native to southwestern Texas, is a dependable spring and fall bloomer. Often seen growing in the ditches in spring, it is a reliable addition to the garden. It tends to get leggy and should be trimmed back after blooming to keep compact. Blooms range in color from white to deep blue.

Other sages to consider for fall color include Texas Sage (S.coccinea), Indigo Spires, Forsythia Sage (S. madrensis), Pineapple Sage (S. elegans) and Scarlet Sage (S. splendens).

Asters are another fall favorite providing brilliant color to the garden. There are more than 600 species of true asters. True asters will grow in most soils, but to achieve luxuriant growth, plant in well drained fertile soil. They have few problems except for mildew in late fall. They perform best in full sun. Although some will tolerate partial shade, they will be less vigorous and produce fewer blooms. 

Strong-growing hybrids can be invasive. Even small fragments left in soil will regrow. Each year in the fall or early spring, divide plants. Take divisions from the outside of the clump and discard the old center. Less vigorous plants should be divided every two years. 

The flowers bloom in large sprays and come in colors of white, blue, red, pink, lavender or purple. 

Another Texas native that will provide color to the fall garden is the flamboyant orange and yellow of Texas Lantana (Lantana horrida). The deep rich colors of the lantana blooms live up to its common name – calico bush.

The multi-branched native shrub grows 2 to 6 feet tall and wide and can be found over most of Texas except the Panhandle. The rough, wrinkled aromatic leaves are ovate to subtriangular with coarsely toothed margins. The yellow and orange tiny flowers have 4 or 5 lobed petals and are clustered in a tight, flat flower head making a perfect landing pad for butterflies in search of nectar. The fruit comes in tight clusters of small blue-black drupes – deadly poisonous. 

Lantana is the perfect drought tolerant shrub for the garden. It will grow in all types of soils as long as it has good drainage. It provides nectar for butterflies and hummers. The hybridized forms come in trailing as well as bush. Colors range from cream to shades of yellow and orange in addition to shades of pink, red and purple. 

Planting verbena, plumbago, esperanza, cupheas and blackfoot daisy will provide more color to the garden. Fall perennials such as fall rain lily, autumn joy sedum, obedient plant, rudbeckia, coreopsis, and mums provide exceptional color to the garden. 

Set out spring-flowering perennials, such as ‘Texas Gold’ columbine, yarrow, ox-eye daisies, purple coneflowers and iris. Planting in the fall allows them enough time to become established before next spring. Plant in beds prepared with organic material and mulch. 

Yarrow was the only plant that stayed healthy and green during the ice storm. It will always have a place in my garden. 

To add more color to the garden, consider planting stock, pansies, foxglove, hollyhock, sweet pea, flowering cabbage, kale, snaps, petunias and larkspur once the temperatures cool off. Broadcast wildflower seed in the fall. 

The addition of some of these plants to the garden will ensure a colorful second season. 

Happy gardening.

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