Sunday, July 14, 2024

Asters signal fall’s arrival


Fall finally arrived with rain, a drop in temperature, changing leaves and autumn flowers. So, after a season of brutal heat and drought, what was blooming? Texas aster, a hardy native perennial, covered itself in violet-blue blooms, which provided brilliant contrast to popular golden-yellow chrysanthemums.

Also known as fall aster or aromatic aster, Aster oblongifolium forms a mounding, deciduous shrub throughout the growing season. Its leaves are small, but fragrant. Because of its low-growing habit, Texas aster makes a nice front-of-the border plant. It also looks good in mass plantings. Since Texas aster has low water needs, grow it alongside other drought-tolerant plants. Do not overwater this aster. It prefers well-drained soil and minimal supplemental water once established.

As with most native plants, Texas aster needs little, if any, fertilizer. If fertilized, the plants can become too leggy and flop over. In the wild, Texas aster grows on rocky soils and alongside native prairie grasses where it receives at least four hours of full sun daily. It requires a sun-to-part-shade site and well-drained soil. Before planting, eliminate weeds and amend the soil with a good landscape mix or compost. After planting, top dress the soil with mulch to minimize weeds and retain soil moisture.

Texas aster grows 2 to 3-feet tall and wide. In fall, these bushy plants sport numerous, small (one inch) daisy-like flowers. Each flower has a yellow center disk encircled by violet-blue petals. Aster’s late bloom provides a much-needed nectar source for migrating butterflies, bees and other pollinators. Because of their fragrant foliage, asters are considered deer resistant.

To keep the plants compact, cut them back by half in May. Trimming back too late in the season can reduce flowering. Whether or not the plants need grooming depends upon the weather. Abundant spring rain results in taller plants that benefit from cutting back. Plants that are frequently irrigated react similarly. In hot, dry environments, asters can be left alone. They grow slowly without moisture.

Texas aster’s showy flowers continue their bloom until late November or later in mild winters. After a hard freeze, the plants die back to the ground except for a green rosette base. Remove dead stalks and dried foliage in late winter to make way for spring growth.

Texas aster is a reliable performer that’s winter hardy north to zone 4, which makes it one of the rare plants that endures both heat and cold. (North Central Texas is rated zone 7/8.) Texas aster has few pest problems, but excess moisture on foliage can promote fungal diseases.

Tip: Plant spring blooming daffodil bulbs amid Texas asters. The daffodils will emerge in late winter and bloom before the asters fill out. These bulbs prefer similar growing conditions, so do not add fertilizer or give them too much water.

For answers to your horticulture questions, please call the Texas A&M AgriLife Extension, Hood County at 817-579-3280 or go online to visit | 817-680-4849