Note: Information for this trials report was provided by Megan Proska, Senior Director of Horticulture at the Dallas Arboretum.
Vinca ‘Volcano Polka’ (Černý Seed Company)
Vinca ‘Volcano Peach’ (Černý Seed Company)
Ipomoea ‘Sweet Caroline Upside Key Lime’ (Proven Winners)
Ipomoea ‘Sweet Caroline’ Upside Black Coffee (Proven Winners)
The summer growing season in Dallas was much hotter and longer than expected. We had more than 40 days with weather above 100°F, and our nightly temperatures remained around 80°F for most of the season. In addition, we had hardly any rainfall between the beginning of June and the end of August. This made for a very difficult trial season, and unfortunately, a good portion of the entries died over the course of the season.
Over the course of summer alone, we trialed 450 different varieties in three different areas. We had in-ground trials, container trials, and hanging basket trials that lasted from mid-May to early September. Overall, the trial went well considering the weather conditions. Many of the entries did die over the course of the season, but that showed us what will truly survive our harsh, and sometimes unpredictable, summer conditions.
One noteworthy thing about our trials this year was that we held over a lot of entries between seasons. For example, between the entries planted in spring and the entries planted in summer, an average data week consisted of nearly 1,000 entries. Many of these entries were different, but some of them were the same variety planted at two different times of the year. This offered a unique opportunity to observe whether or not the time of establishment affected the plants’ survival rate in the summer. For many of the plants, they performed well during the spring but would slowly decline as the weather got hotter. In contrast, a few plants performed well throughout the summer regardless of their planting date.
The biggest challenge for our trials this year was an unrelenting heatwave combined with an unforgiving dry spell. These conditions made it very difficult to accurately evaluate the entries. Some of the plants may do well under more average conditions but struggled under the conditions in our area. We primarily overcame this challenge by increasing our summer irrigation level, whether that be by increasing the total time allotted to a zone per day or increasing the frequency of the irrigation program. This was essential for our perennial trials.
Two Ways to Determine Vapor Pressure Deficit in the Greenhouse
Impressive Plants This Year
- Sweet Caroline Upside Key Lime and Upside Black Coffee sweet potato vine from Proven Winners. These plants performed admirably no matter when they were planted or in which type of trial. In addition, trellising these plants on tomato cages when grown in-ground provides a fun and unique addition to any garden. Many people commented on how much they loved the idea.
- Volcano Peach and Volcano Polka Dot vinca from Černý Seed Company. The plants performed well throughout the Spring and Summer Trials. The coloration of the flowers was also gorgeous. The Peach color was actually a true peach color with an orange undertone that is not typically found in other vinca series, which tend to have more of a pink undertone.
Learn more about other field trials from 2023 here.