Plants 7 Weeks and won't Flower

I've done everything by the book, but they just keep on growing!

Answer: Without knowing exactly what varieties of plant you are gardening, I will have to break down your problem into one of three categories. The first category would be for plants that do not require a regular dark period to trigger flowering. For these type of plants, the chronological age of the plant will determine when the plant begins its flowering stage. If you are growing one of these types of plants, it could be possible that the plants are waiting to reach 8 weeks of maturity or 9 weeks of maturity before they go into flowering. In fact, depending on what you are growing, it could take even longer than that.

Chances are a little better that you are growing some type of plant that DOES require a regular dark period to trigger flowering. For a crash course, visit my flower forcing page. Most plants that require a dark period will do just fine under a 12-12 light cycle. This means 12 hours of light, followed by 12 hours of darkness. The lights should come on and go off at the SAME TIME every day. Your grow room should be made light proof, and the dark period should NEVER be interrupted by any light. Plants tell when the days are getting shorter and when they are getting longer by counting the length of the DARKNESS each night.

If you interrupt this count (with light during the dark period) the plant will think it is heading back into summer, and for the next whole day your plants will spend all of their energy reverting back into the vegetative stage. Normally, you should notice signs of flowering within 14 days after changing the light cycle to 12-12. However, if you interrupted the dark period at some point you may have delayed the onset of flowering. In this case make sure your grow room is light proof, make sure your dark period is regular, and be patient.

Finally, it is possible you are growing some type of plant found naturally around the equator (a tropical plant). The area around the equator receives much less natural fluctuation in the suns photo period between Summer and Winter. As a result, these types of plants sometimes require a dark period longer than 12 hours to trigger them into flowering. If you feel that this is more probably your case, than you will want to increase your dark period to 11 1/2 hours on, 12 1/2 hours off. This should be enough to coax even the most stubborn plants into flowering, although I have read of some people using a light cycle with 13 hours of darkness! Just as before, you should notice signs of flowering within 14 days after changing your light cycle.

If that doesn't do the trick, than you definitely have light getting into your grow room somehow during the dark period. I hope this helps, and Happy Growing!