Spring-flowering shrubs and trees that open buds in autumn are displaying a documented stress reaction rather than a sign of decline, according to Ohio State University Extension guidance reported by FOX 8.
The pattern is described as remontant, or repeat, blooming. University guidance states the behavior generally does not damage the plant and is typically a reaction to environmental conditions.
Erik Draper, a former Geauga County OSU Extension educator, addressed the subject in that material. He disputed the belief that off-season flowering means a plant is preparing to die, describing reblooming as an acceptable reaction to weather-driven environmental stimulants. Cooler, wetter spells or mild temperatures following intense heat can be interpreted by some plants as a rest period, prompting dormant buds to open, he wrote.
Epic Gardening likewise notes that warm fall conditions can imitate the spring warmth that follows frost. The result for gardeners can be a second showing of pink, purple and red flowers within one season.
FOX 8's page also carries a video segment on allergy-season advice from an allergist.