Plant Trials

Rows of plants in growing pots sift on a lifted metal shelf in a greenhouse
Fred Zwiebel

Our Amazing Displays Start with Research

Each year, we work to increase the diversity and quality of our displays by introducing new plants into our Gardens. These come from across the country and around the world and may have been requested by one of our staff members, discovered during plant exploration, or received from a plant breeding company.

Once Longwood receives plant specimens or seeds, our researchers put them into trial. Trial plants are grown in our 4,035-square-foot research greenhouses, our 1.6-acre research nursery, and in our Idea Garden. We trial around 500 new plants every year.

Selecting Plants for Display

Twice a month, our Plant Evaluation Committee—which includes our display designer, research team, gardeners, growers, students, and representatives from our integrated pest management program—meets to evaluate a new group of plants. Each trial plant is evaluated when the research team feels the specimen has reached its maximum display potential or highest aesthetic value. During this process, our researchers introduce each plant, including its origin, growing conditions, and why it was selected. The Plant Evaluation Committee then discusses whether the plant is suitable for use in display or should be discarded.

Improving Plant Culture

Sometimes, plants require further work or study and they are put back into trial. For example, Pride-of-Tenerife (Echium simplex) is a rare plant native to the Canary Islands that has an enormous inflorescence that regularly reaches over one meter in height. This plant first came to Longwood in 1987 as a result of a plant exploration trip to South Africa. The evaluation period for this plant was short-lived, since it had such spectacular tall white flower spikes, and it was moved into production almost immediately.

Production of this crop is challenging, since it is a biennial plant and takes well over a year to produce a flower spike from seed. Thus, the plant came back into Research, so the staff could determine the optimal seed sowing date to reduce the long production time, while maintaining plant and inflorescence size. To do this, they planted seeds on the first of December, February, March, and April, and closely monitored growing conditions in the greenhouse for optimal results.

Researchers found that the sowing date had a significant effect on the size of the flower spike or inflorescence. Plants sown in April were significantly shorter and had reduced inflorescence compared to plants sown in December. The sowing date had minimal effect on plants that were sown between December and March. These findings indicate that sowing dates as late as March 1 are suitable for the production of high quality Echium simplex, which helps reduce production times.