Purists will say that using natural sunlight for growing your cannabis is the only way to go. I find it hard to outright disagree – and solid arguments can be made either way. It is certainly the most cost-effective way to grow. However, it is not as easy as just sticking a cannabis seedling in a window. Most cannabis are photoperiod plants (“photos”). This means that they respond to the light/dark cycles of the sun or artificial lights. Here I’ll describe what that means to you and your Missouri medical cannabis garden.
Missouri cultivators can get a surprise when trying to grow in natural sunlight. The fact is, your cannabis will flower immediately when exposed to sunlight only – about 9 months out of the year. Between the months of April – June, your cannabis will vegetate happily, but not the rest of the year. Why is that?
It has to do with the amount of daylight and the behavior of our natural solar rhythms. Starting in April, plants in Missouri will receive 13 hours of daylight and only 11 hours of darkness. Additionally, the days grow longer by a few minutes every day. This combination indicates to the plant that it has a long summer to look forward to and it will vegetate merrily until around June 21 – at which point it will begin to flower. The amount of darkness has less effect here as the flower inducement comes with a decreasing daylight and increasing nigh periods. The signal is now that fall is coming and it is time to reproduce.
This is true, even if you are attempting to grow in a window. No matter the age of your plant, it will begin to flower in that window except between April – June. If possible, you will need to provide supplemental lighting in the morning, evening, or both in order to ensure that the plant gets 14 or more hours of light. Then, when you are ready to flower, simply turn off the artificial light and off you go. NOTE: I do not recommend growing in a window as it is almost certainly against Missouri regulations. If you do, make sure it is a south facing window.
It is also important to understand that if you start your seedlings indoors, under 18/6 (hours on/off) lighting, they will want to flower as soon as you move those seedlings outdoors. So what are you to do?
Starting seeds directly outdoors: plant your seeds when the soil reaches 55 degrees – usually in early April. Good Friday is a good date to remember and would be when a seed would germinate naturally. You can plant in the last week of March if protected in a cold-frame or similar structure. Starting much earlier can induce flowering. For example, most strains will flower if you start them in early March. I know this from experience – the days are still just too short. Cannabis will tolerate a light frost as long as the day warms quickly. It is best to wait until after the last frost or be prepared to protect them on the coolest nights. Treat them like tomatoes.
Starting cannabis inside to take outdoors: whether starting seeds or cuttings, if you start them under 18/6 lighting then you should adjust your timing so that they are planted outdoors the second week of June in Missouri. After about two weeks the hormones will have shifted the plant into flowering mode. By then, summer solstice will have passed and days will begin to shorten. As such, you plants will continue to flower as expected. If you put these plants out too early they will shift to flower, then back to veg, and once again to flower when June 21 passes. This is a mess and should be avoided.
Do you have an experience with timing for outdoor grows? We’d love to hear your feedback.
Happy Harvests!
— The Lit Farmer —