How Much Sunlight Do Outdoor Cannabis Plants Need To Grow?

HOW MUCH SUNLIGHT FOR PHOTOPERIOD CANNABIS?

Photoperiod cannabis strains are conventional short-day marijuana that requires a 12-12 light cycle. This simply means 12 hours of light followed by 12 hours of darkness to bloom. Indoor growers use a timer to set the standard 18-6 light schedule for vegetative growth too. Of course, there are many variations, and some growers prefer a continuous 24 hours of light. Cannabis can survive with as few as 6 hours of daily sunlight. But we like to see weed thrive, so we get started outdoors when the days are longest.

Outdoors, mother nature is in control. However, by studying her habits, we have learned when and where to grow the best natural marijuana. After the spring equinox, the days will grow longer until the summer solstice, when the hours of daylight begin to decrease. Long nights are what triggers photoperiod cannabis to flower. Without the sudden switch to 12-12, this will be a more gradual transition outdoors. The hours of natural sunlight decrease by a few minutes per week.

HOW MUCH SUNLIGHT FOR AUTOFLOWERING CANNABIS?

All autoflowering cannabis strains are not created equal, but they do have one thing in common; the clock is counting down to harvest day the moment an autoflower sprouts. These days, this means your plant will complete her lifecycle within 8–12 weeks. Essentially, autos begin to flower somewhere between day 25–35 post-germination.

Unlike photoperiod cannabis, which takes its cue from the sun, an autoflowering cannabis strain does not require long, uninterrupted dark periods to bloom. The contemporary autoflowering hybrid prefers longer days, but can cope better than the average photoperiod with interruptions and weaker sunlight. Moreover, street lights and the neighbour's sensor light won’t confuse them into reverting to vegetative growth like they would a photoperiod. Autos are more versatile and biologically programmed to transition to bloom by week 5.

THE OUTDOOR GROWING SEASONS EXPLAINED

OK, so we all understand the Earth is orbiting the sun. But it’s not the distance between the Earth and the sun that’s responsible for the change in the seasons. It’s an elliptical orbit, so the distance actually varies. The seasons change because the Earth’s spinning around sort of on a slant.

The planet’s axis is tilted at an angle of approximately 23.4 degrees. And this is what causes the North Pole to tilt toward the sun during the summer months June, July, and August in the Northern Hemisphere. Meanwhile, it’s winter during this same period in the Southern Hemisphere.

SPRING

Sometime after the spring equinox and before the end of April is the best time to get started with photoperiod cannabis strains across the Mediterranean. The days will be long and the temperatures warm enough for most varieties, from heavy indicas like Northern Lights to super sativas like Amnesia Haze, and everything in between. Plants will grow to enormous proportions and have a lengthy natural vegetative growth phase. Most autos are also a viable option for an early harvest.

These are not the same climatic conditions as most of Northern Europe in the springtime. At least not yet. Extreme weather like hail and snow is not uncommon even in March. Long, overcast days and freezing temperatures are not conducive to outdoor cannabis cultivation.

SUMMER

Southern European growers will see their mature photoperiod plants burst into bloom during the summer months. By late-August, weed trees of Critical and Shining Silver Haze will be positively bud-laden. Alternatively, if you started with a hardy, skunky auto like Royal Dwarf or Quick One, you could be planning your second summer crop of gourmet autos like Royal Cookies Automatic or Royal Gorilla Automatic.

Further north, you might just be getting started. By the summer solstice, a natural change occurs. After this apex of the sun's motion the days get shorter and the nights longer. Photoperiod strains will grow smaller and bloom sooner after this point. Autos will also be more squat. Yields can still be high, provided plants get plenty of direct daily sunlight and nighttime temps don’t dip below 10°C. Fast-flowering strains like Royal Cheese and Candy Kush Express will complete the bloom phase in shorter northern summers. Royal Bluematic can also deliver a tasty stash in a hurry from a sunny balcony.

AUTUMN

“Rage, rage against the dying of the light” —Dylan Thomas

This is why October came to be known as “Croptober” by US ganja farmers. September and October are the months when it’s time to harvest across most of the Northern Hemisphere. Daily hours of sunlight might be on the verge of sliding into single digits in the far north already. And don’t forget, “Winter is coming”. Rains will spoil fat colas with mould. Sometimes it’s safer to harvest a little early if you expect the weather to take a turn for the worse. Celebrate and harvest before you lose the light to long nights of winter.

WINTER

As they say in the mafia, “Fuuget About It!” Halloween is more or less the unofficial final curtain for cannabis cultivation in the Northern Hemisphere. Winter chronic is a fugazi!

JUMPSTART THE CROP INDOORS

No matter when or where you plan to grow outdoors, it helps to jumpstart the crop indoors if possible. If you have an indoor grow-op, or even just a cool white 200W CFL lamp, you can at least start the grow with an optimal 18-6 vegetative cycle for a couple of weeks. Once seedlings or clones have rooted, they stand a much greater chance of surviving the elements outdoors.