Todd McCormick said if you put photo plants out before may 15th they will flower, that the only time plants veg outdoors is may 15th to the summer solstice. Îs this true to any outdoor growers? But what would stop the plants from revegging when the days got longer? Thanks
1. Who is Todd McCormick?
2. Regardless of photoperiod or autoflower designations for flowering, within these plants, there exists a further division that puts some plants into qualitative and quantitative groups that require specific conditions to perform certain biological tasks, or will still carry out tasks, but sub optimally until conditions are met.
Photoperiods don't flower out based on the amount of light they receive, but the amount of darkness.
Winter solstice is December 21st here in the USA. Using Colorado for example (where I've grown outdoors,) that puts about 9 hours 20 minutes of actual daylight during the 24 hour period.
Fast forward to February 21st, and it's around 11 hours of actual daylight.
Fast Forward to April 21st, and it's almost 13 1/2 hours of daylight.
By May 21st, you're seeing almost 14 1/2 hours of daylight.
Keep in mind, these are sunrise to sunset, and these values do not remotely mean that they are getting 100% of the same quality of light (spectrum, intensity) during the entire time. This also doesn't account for where the plants are physically planted, if there is natural shade covering, or man-made coverings (shade cloth, under a deck roof, etc.)
12/12 is just a standard for flipping for indoor growers, many cannabis plants will still flower even with a bit more light during a 24 hour period.
It's not just the amount of daylight hours though either; it's also the intensity of the light. Let's look at DLI values for Colorado in December, February, April, and May:
December: 15-20 DLI
February: 20-30 DLI
April: 40-50 DLI
May: upwards to 50+ DLI
So the actual light intensity, not just the amount of light, nearly TRIPLES as you go from December to May. So even if there enough light hours to sustain vegetation vs flowering, there has to be enough light intensity to support proper photosynthesis, or they aren't going to grow very fast even if they are just chillin' there vegetating (let alone if the temperature and weather even allows such things.)
