PLANT CALENDARS
Erica's Original Notes: The length of day or night triggers Nature's switches, as in winter when the sap thickens, promoting resistance to cold. Plants may belong to one of the following groups:
Short day: These plants need a long uninterrupted night in order to form buds; violets and goldenrod belong to this group; just a flash of light will upset the rhythm. Chrysanthemums can tell the difference between 14 and 15 hours of light; growers use these time clocks in greenhouses to control flowering, and this is one of the boring reasons we find mums in florist shops throughout the year!
Long day: These plants are typified by irises and clover.
Neutral day: Roses, carnations and African violets are in this group, which needs 12 hours of night. Nighttime is plant growth time, while daytime is for photosynthesizing, a time for assimilating vitality. Arctic plants are stunted by light due to the long summer hours.
Rhythms: There are many rhythms affecting the plant world: circadian (daily), lunar, solar, and seasonal; so far, only the hands of the biological clock have been studied, but the nature of the clock itself is unknown.
Useful Links:
Plant Circadian Rhythms
Short day: These plants need a long uninterrupted night in order to form buds; violets and goldenrod belong to this group; just a flash of light will upset the rhythm. Chrysanthemums can tell the difference between 14 and 15 hours of light; growers use these time clocks in greenhouses to control flowering, and this is one of the boring reasons we find mums in florist shops throughout the year!
Long day: These plants are typified by irises and clover.
Neutral day: Roses, carnations and African violets are in this group, which needs 12 hours of night. Nighttime is plant growth time, while daytime is for photosynthesizing, a time for assimilating vitality. Arctic plants are stunted by light due to the long summer hours.
Rhythms: There are many rhythms affecting the plant world: circadian (daily), lunar, solar, and seasonal; so far, only the hands of the biological clock have been studied, but the nature of the clock itself is unknown.
Useful Links:
Plant Circadian Rhythms
