De Kwakel, April – To determine which cut hydrangeas from breeder HBA are suitable for season advancement, HBA is conducting a so-called “early forcing trial.” The trial includes all HBA cut varieties, along with several numbered selections. “The results are quite interesting,” says breeder Niels Arts.
“We’re investigating which HBA varieties can be harvested early, without the need for heating. That’s exactly what this early forcing trial is designed to uncover,” he explains while walking past the test plots, pointing out several varieties that are showing promising performance. “All the cut hydrangeas in the trial were pruned back on July 1, 2025,” he adds.
He gently moves aside some leaves to demonstrate the difference between terminal buds and lateral buds. “Stems that develop from terminal buds tend to flower earlier than those growing from lateral buds,” he shows. “At first glance, you could say that varieties with terminal buds are more suitable for season advancement,” he concludes. “However, there are several other factors that determine whether a hydrangea variety can be successfully forced early.”
For example, after pruning in July 2025, the regrowth during summer and autumn must achieve sufficient length. In the following spring, it is important that the stem emerging from the terminal bud continues to elongate significantly, and that the flower reaches a good size and has strong vase life.
Within the HBA assortment, several varieties appear to meet all these criteria and may be suitable for early forcing. HBA is pleased to share the preliminary results of the trial with growers during Hydrangea Night, traditionally held in the week of the Flower Trials. The Hydrangea Night on June 11 is an invitation-only event. If you have not yet received an invitation but would like to attend, please contact Jaap Stelder at +31 6 514 08 341 or via jaap.stelder@agriom.nl.