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The 2009 ASHS Annual Conference

Tecoma Grown In Bags Outperform Plants Grown In the Ground

Monday, July 27, 2009
Illinois/Missouri/Meramec (Millennium Hotel St. Louis)
Clydette M. Alsup, Missouri State Univ, Springfield, MO
Pamela B. Trewatha, Ph.D., W. H. Darr School of Agriculture, Missouri State University, Springfield, MO
Abstract. Ornamental plants seldom thrive in poor soil conditions, yet in most landscapes the soil must be tilled and amended or mounded into raised beds before a garden can be established. Proper soil preparation can be laborious, expensive and time-consuming, which may discourage many homeowners from establishing ornamental gardens. Gardening in a bag allows gardeners to create instant raised beds. This study evaluated the performance of Tecoma stans ‘Mayan Gold’ grown in the ground or grown in paper bags containing 3/4ths of a cubic foot of topsoil or potting mix. Tecoma seedlings were planted on 5 June in the ground or in bags placed on top of the ground, and data were collected on 22 July and 13 September. In July, Tecoma plants growing in the topsoil or potting mix bag treatments fared significantly better than those growing in the ground, in all parameters measured. Plants grown in the bags with potting mix were significantly taller and wider, and earned better visual quality ratings than those grown in bags of topsoil, but potting mix vs. topsoil made no significant difference in number of flowers. Plants grown in the ground had only barely initiated flowering by 22 July, while those grown in the bags averaged 9 to 10 flowers per plant. Data were not taken in August because plants were suffering from extremely wet conditions—more than 13 inches of rain fell in less than one week in early August. Forty percent of the plants in the saturated ground died, whereas no plants in bags died. By September, plants in bags of potting mix were more than twice as tall and three times as wide as the surviving plants grown in the ground, and were taller and wider than plants growing in bags containing topsoil. Tecoma growing in bags of potting mix maintained the highest visual quality ratings of the three treatments. Both bag treatments also produced plants with larger leaves than in-ground plants. Bag-grown plants continued flowering in September, while ground-grown plants were not flowering. Overall, the bags with the potting mix produced the largest, best quality plants, and they tended to have the most flowers.