In various articles you have described plants as long day, short day and neutral. Do you mean daylight hours? How do plants respond to changes in day length?
Photoperiod or photoperiod is a major factor that plants use for various processes. Plants use day length to tell them when to go dormant in the fall and when to emerge from dormancy in the spring.
Most of us think it’s a change in temperature that triggers dormancy. However, temperature changes are variable and may not be precise enough to protect plants from abrupt fall temperatures. Likewise, periods of unusually warm winters can stimulate new growth that is damaged by a return to normal cold. I’ve noticed that it’s starting to drop .
Flower formation and subsequent fruit and seed development is another major growth process controlled by photoperiod. Most of the spring and summer flowers that we grow in our gardens are long-day plants. Not all bloom at the same time. Each cultivar is triggered to begin flowering at a specific day length and often continues blooming until the short day length is reached again.
Autumn flowers like chrysanthemums are short-day plants, which begin flowering when a certain short day length is reached. Greenhouse growers can use black cloth and lights to keep chrysanthemums blooming at any time of the year.
The development of diurnal strawberry varieties for the California strawberry industry is an interesting story. I realized that This indicated a state of neutrality during the day. Until then, all garden and commercial strawberry cultivars were long-day plants bearing fruit from late June to July, up to his 6 weeks.
Bringhurst crosses Utah wild plants with commercial varieties and selects for commercial size and quality, as well as daytime neutrality traits. These varieties have borne fruit for a full season in coastal California. We also have summer and fall production in Washington and Oregon. The University of California strawberry variety sold locally is Seascape.
Most perennial flowers are long-day plants with a limited flowering period. However, there are some perennials that are naturally day-neutral and have a much longer flowering period.My three favorites of his are Geranium Roseanne, Coreopsis Moonbeam and Lily of Peru (Alstroemeria).
Green Fuse Botanicals has a breeding program that develops day-neutral perennial flowers for extended flowering.
The first to be introduced is the All-America Selection Award-winning Ground Cover Shasta Daisy Carpet Angel.
Green Fuse does not sell directly to gardeners, only greenhouse wholesalers sell to retailers. These new day-neutral perennial varieties will be branded under the name First Light. I suspect you’ll see some of them soon at full-service retailers and garden centers.