Salvias are one of the most commonly grown bedding plants across the country. They grow and flower quickly, producing spikes of red, white, pink, blue, and purple flowers all summer long. However, in hot summer areas, the high temperatures can cause damage to the plant and a reduction in flowering.
Although all salvias are considered heat tolerant, there is some variation in performance, depending on the variety. Researchers at Louisiana State University selected two of the most popular salvia series -- Vista and Sizzler -- and tested their performance under high temperatures. Three-week-old seedlings were exposed to 3-hour-long treatments at high-temperatures (86, 95, 104 and 113 oF) every three days until flowering. Both salvia series died when exposed to 113oF treatments. However, at the 95 and 104oF levels, Vista cell membranes were less damaged and the plants had thicker, more erect leaves and less leaf scorching.
For gardeners growing bedding plants in hot summer areas, the Vista salvia series would be the best choices to grow. Researchers plan on using this test to trial other bedding plant lines to determine their ability to withstand high heat.
For more information on this research go to the Louisiana State University Web site.