So it sure appears that plants have an internal clock. A Prarie Home Companion refers to Norwegian Bachelor Farmers who continue to wear long underwear until April, even if gets to be 65 degrees in March. It just isn't summer yet. Hard on crews and couldn't share equipment efficiently. By chance, a tobacco field existed outside their lab office.
Tobacco is planted in early spring and harvested in summer just before it begins to flower.
Garner and Allard noticed that one plant didn't form flowers in the summer, instead it just kept getting bigger. Ultimately grew to 3 meters in height, so got nickname of Maryland Mammoth. Still hadn't flowered in September, so cuttings taken, and grown in greenhouse to perpetuate this strain. Dug up plant from field and brought it into greenhouse, too. Seeds were collected from these plants and these, too, grew all summer long and flowered in winter, no matter how early in the spring they were planted.