But if you want high-grade weed, you need to be a little more patient. Purists can germinate seeds and start them on a sunny windowsill. As daily sunlight reaches 15 hours and the temperatures stay consistently in the low-mid-teens, it’s finally the right time for most to grow outdoors. Classic Skunk and Northern Lights by Zamnesia Seeds are solid choices. Alternatively, you can start a dank super auto like Royal Gorilla Automatic by RQS or Devil Cream Auto by Sweet Seeds.
However, if you got started inside, May is the month to harden off and make a move. Start by potting up to large 10–20l final containers. Use your artificial light to supplement the hours of natural sunlight. By the end of the month, they are ready to grow outside permanently. With a little luck, temperatures will be in the high teens, and by the summer solstice on the 21st, daily sunlight will peak at 16 hours and 38 minutes. Autos germinated in March/April will be ready for harvest this month. Provided they have been sheltered from rain, the buds will be of respectable quality and a decent yield can be expected.
Photoperiod strains will vegetate comfortably and still have enough time to grow to large sizes and yield heavily. Sun-flowered autos started in May will be ready for the chop this month. You could potentially be harvesting your second crop if you get your timing right and selected the right genetics. Most photoperiod strains will still be in vegetative growth and it could be time to do some pruning and training if plants are beginning to turn into trees. Temperatures in the low 20s and 15+ hours of sunlight are great conditions for growing cannabis. Photoperiod strains will begin slowly transitioning to the bloom phase this month. And if you got a late start with your autos, don’t fret; you still have time to finish flowering this month. By the end of the month, you are back down to about 13.5 hours of sunlight per day. This is not a perfect 12-12 light-dark cycle and is the reason why photoperiod strains take far longer to bloom outdoors. If you have a greenhouse, you can cover it over with light-proof sheeting to reduce the hours of natural light and speed up flowering. If you haven’t already, now is a great time to build a simple shelter for cannabis plants in mid-late bloom. Daily sunlight will decrease from 13 hours and 34 minutes to 11 hours and 39 minutes in 30 days. High humidity and decreasing temperatures to the low teens are a recipe for bud rot. Better to harvest a little early than to lose the crop. Photoperiod plants should be harvested towards the end of the month. September is potentially a third auto harvest month. Autos sprouted in June/July will certainly be ready. You had better be close to the finish line to be still growing this late in the year. Temperatures will be 10°C at best and sunlight is fading fast. By Halloween, daily sunlight hours will be back down to single digits. November, December, and January are months for hibernating with a fat stash. Cannabis, like most plants on earth, germinates and begins growth at the beginning of spring. Celestially speaking, no matter what the actual date is on a calendar, spring is considered to begin around the full moon of March or the Vernal Equinox. This doesn’t mean that spring signals “germinate some seeds and go” everywhere simultaneously. When cannabis is germinated too early, or when the daylight hours are still below 12 hours, seeds will still germinate, then show sex early and continue to grow into a lovely plant.
However, at the important bud stage, they will be fluffy and poorly formed and have disappointing yields. It is tempting to try and get ahead of the curve by planting early, but it always leads to disappointment in the end. Although frustrating, it is better to wait later in the season until the daylight is at least 12 hours. You will have a slightly smaller plant, but with a considerably heavier yield of much better formed buds. In February, the days are too short and temperatures still too cold for natural germination. If you have a greenhouse and some supplemental lighting, it is a good time to germinate. Once the plants are established and well-rooted, they will be ready to be put outside to harden off once the weather starts to warm and the days get longer. February should be spent preparing pots or giving organic gardens a final amendment and mulching. Seeds can be bought in preparation for the oncoming growing season. Be sure to read the breeder's stats to guarantee you get a strain suited to your circumstances.
Some supplemental lighting is still required to assure over 12 hour long days.