Final Summary of Eustoma Grandflora Trials

On January 6, 2006 UNH Cooperative Extension planted a research plot of Eustoma grandiflora plants at Spring Ledge Farm in New London. The purpose of the test was to see which out of the 6 varieties produced the greatest amount of salable flowers with the highest quality and to see if high tunnels would produce saleable plants earlier in the season and with higher quality than the field grown plants. 

All plants were planted from a 288 plug tray into beds with black plastic and a drip line going down the center of the beds for irrigation and fertilizer. Each plot was three feet long by two feet across and had 36 plants of each cultivar. There were two rows in the field with nine plots each and one row of plants in the high tunnel with 14 plots. The ends of each row were planted with Eustoma that were not part of the experiment as part of a buffer against environmental differences. The same varieties were planted in the field as in the high tunnel and included Echo Blue, ABC Blue, Cinderella Blue, Cinderella Pink, Laguna Rose and Twinkle Blue Blush. In the field each cultivar was planted in three separate plots. In the high tunnel each cultivar was planted in two plots.

The prepared beds included a pre plant incorporation of ProGro and the outdoor beds were given 200ppm of 21-5-20 in the spring and Cal Mag 15-5-15 in the summer on an as needed basis. The plants in the high tunnel received 100 ppm of Cal Mag 15-5-15 on as add needed basis.

Plants were harvested when needed to supply the store with a regular supply of flowers. For data comparisons harvest days were lumped into weeks beginning on Saturday. Eustomas are harvested when at least one bud is half way open. Most plots had harvestable plants on August 5th, 2006 but these plants were not considered salable, as their stems were less than 12 inches long. At this time, the plants in the fields and in the tunnels had similar numbers of harvestable plants. However, the plots in the tunnels had the greatest numbers of salable plants on August 12th, where the plants in the field had the greatest number of salable plants later in the season (September 2nd and 9th). This indicates that high tunnels have the potential to produce salable stems before the field grown crops. Plants in the high tunnels also produced taller plants with 128 stems between 16 to 18 inches harvested in a 6-week period compared to only 13 stems produced in the field.

Out of the six varieties that were grown, Cinderella Blue and Twinkle Blue Blush produced the most salable stems with a grand total of 270 and 339 stems, respectively, over a 6-week period. It should be mentioned that due to a lack of plants, Twinkle Blue Blush was planted in only 4 plots as opposed the other varieties that were planted in 5 plots, yet it still produced the most salable stems. Surprisingly, the industry standard, Echo Blue, and the variety similar to it, ABC Blue gave the least amount of salable stems, a grand total of 169 and 162 stems, respectively, over a 6-week period.

All varieties had high quality stems with multiple branches and blooms. Laguna Rose seemed to have more branches than the others. All varieties had spots on the flowers that made the plants unsalable at times. Flowers in the high tunnel had and equal amount of spots as in the fields. This may be due to the condensation that builds in the tunnels and the unusually humid and wet spring. 

These results should not be understood as scientific conclusions. The growing season was unseasonable wet and conditions in the field were not consistent. Some areas were excessively wet all season and other areas dried out by early July. Also, Spring Ledge Farm is a cut-your-own farm and some plants in the field may have been harvested by patrons without our knowledge. No statistics were run on these numbers; these conclusions are based on comparing the grand totals, but it cannot be said that the differences in numbers are statistically significant.

We’d like to thank Spring Ledge for donating their time and land for this trial and for caring and maintaining the plants. We’d like to particularly send our gratitude to Heidi Molton for harvesting, measuring, and recording all 1400 stems!