The first day of summer, June 22, is the longest day of the year, and the time when the sun’s rays reach the northern hemisphere most directly, giving it the brightest light. After that, each day grows shorter and sunlight reaches the hemisphere at a more oblique angle, making it dimmer until the first day of winter, December 22, when light intensity and duration begins to increase.
Marijuana plants can be forced to flower at any stage or size by providing a 12-hour period of uninterrupted darkness each day. 50 to 70 days after such forcing, the buds will be ready for harvest. So a plant forced in the beginning of June will be ready around the beginning of August. Plants forced in early July are ready the beginning of September.
Several strategies can be used to produce early harvests:
In areas where plants can be placed outdoors in the early spring, they can grow vegetatively for six to eight weeks and then be forced to flower using a frame or hoop that encloses the garden. The garden is covered each day at 7pm with an opaque polyethylene cover. It is uncovered each morning at 7am. Polyethylene, white on one side and black on the other, is an ideal material for this. The white side is placed on the outside to reflect the light. The black side is opaque.
In spring, some areas are warm and sunny during the day but have a large temperature drop in the evenings. Plants in moveable containers can be placed outside each day and returned to the warmth and safety of the indoors each evening.
Plants can be grown indoors vegetatively and then set out to flower as soon as weather permits. After March 22, they have to be covered nightly. If you can place plants outside in February you will be harvesting in April, and nature will provide the correct dark period for you. The small decrease in the length of the dark period will not send the plants back into vegetative growth. Buds grown for spring harvest receive the benefit of increasing light intensity as they ripen.
Plants that are ripened in the spring or early summer should not be cut down. Instead, cut off just the buds. The decreasing dark period the plants receive each day will force them back into vegetative growth. They will then flower again in the fall, and be ready for their second harvest at normal ripening time.
A taste test of the two groups of buds, early and late, from the same plants will confirm my observation that buds ripening between July 1 and August 15 are the most potent and tasty.
Readers with grow questions (or answers) should send them to Ed at: Ask Ed, PMB 147, 530 Divisadero St., San Francisco, California 94117, USA. You can also email Ed at AskEd@cannabisculture.com, and send queries via his websites at www.ask-ed.net. All featured questions will be rewarded with a copy of Ed’s new book, Best of Ask Ed: Your Marijuana Questions Answered. Sorry, Ed cannot send personal replies to your questions.