Growth and Flowering of Salvia nemorosa ‘Ostfrieland' in Response to Reduced Irrigation1

Reduced irrigation (RI) can conserve water and control plant growth; however, the timing of RI applications can impact plant growth and flowering. The goal of this research was to quantify growth of Salvia nemorosa L. ‘Ostfrieland' (East Friesland) in response to RI. A soil-moisture sensor automated irrigation system was used to apply four irrigation treatments: RI and well-watered (WW) controls (20% and 38% substrate water content) and two combination treatments to apply RI for either the first two weeks (20% followed by 38%, RIWW ) or final four weeks (38% followed by 20%, WWRI ) of the six-week study. Flower number, height, compactness, and relative chlorophyll content (SPAD) were not different across treatments. Average flower stem length was greater for the WW and RIWW treatments than for the RI treatment. Shoot dry weight was less for the RI treatment compared to the WW and RIWW treatments, respectively]. Cumulative irrigation volume was lowest for the RI treatment and highest for the RIWW treatment. Visually, plants in the RIWW treatment had an open, floppy habit that would likely negatively impact sales in a retail setting. Plants in the RI treatment were smaller, but visually appealing. Index words: soil moisture sensor, plant production, herbaceous perennial, container plants. Species used in this study: ‘Ostfrieland' salvia (Salvia nemorosa L.).