Growing marijuana basing on latitude

Marijuana is a plant that grows outdoors throughout the entire world - except in the Poles - either wild or under the care of a farmer. For a crop to be successful, we must consider when to grow it and the most suitable marijuana strain to use. This post aims to provide information on growing marijuana based on the latitude in which we are.

Climate world map
Climate world map

The latitude on the Earth has a direct impact on photoperiod, in other words, on the daily hours of darkness and sunlight. In turn, latitude also determines the planet's geographical zones. Taking into account that marijuana is an annual plant - it germinates, flowers and is harvested in the same year - and that its different phases are related to the photoperiod, we come to the logical conclusion that, based on our geographical zone in the planet, the growing period of cannabis varies. Mild temperatures and low humidity during the flowering stage provide the ideal conditions for harvesting top quality marijuana.

To simplify the information, as it's a very broad subject, three major areas have been identified: northern hemisphere, intertropical zone and southern hemisphere.

Growing marijuana in the Northern Hemisphere

It comprises the half of the world that is north of the equator. The longest day in the year occurs between 20 and 23 June (summer solstice). The shortest day (winter solstice) is between 20 and 23 December. Day and night are the same length (equinox) on 20 March and 22 September. For cannabis farming, we will mainly focus on two areas: the Iberian Peninsula and the Canary Islands.

Marijuana in the Iberian Peninsula

It is situated between the 36º and 44º North. Although its climate is mild due to its latitude, crops must be adjusted to the climate and latitude of the area where they are grown.

Early Maroc from Philosopher Seeds, almost ready to harvest
Early Maroc from Philosopher Seeds, almost ready to harvest

Luckily, in the Iberian Peninsula almost all marijuana strains grow in perfect conditions. The only problems that a grower may encounter are with equatorial sativa strains that can finish their flowering by the end of November or even December.

The ideal months to start growing marijuana are March, April, May and June. You can also do it in July and August, but only the autoflowering strains are recommended in this case, for they do not depend on photoperiod but need a maximum of sunshine - and daily light hours - for a productive yield. In addition to the last chances of frost during spring, choosing the month we start growing depends basically on the strain and its needs, so if we have enough space, planting during the waning moon in March can produce large plants of the size of Moby Dick from Dinafem, Domina Haze from Kannabia or Jack Herer from Sensi Seeds.

If you are growing marijuana on a terrace or in pots, April and May are ideal months to start growing early strains. Early Maroc from Philosopher Seeds is an option to bear in mind, as it can be harvested in the first half of August. Plant it in June if you want to control the height or reduce the growing time of sativa strains. Notice that the cycle of cannabis plants ends in Autumn, so you should choose the fastest plants according to the Iberian Peninsula latitude, as they can be harvested before the cold and heavy rain period start.

Types of weed for the Canary Islands

The Canaries are located between 27º37' and 29º25' North. The climate is mainly subtropical, but it varies depending on altitude and slope, north and south. Except in areas with cooler microclimates, on these "lucky" islands you can grow at least two outdoor crops per year naturally. The planting months are from March to June and from September to November, to be harvested in March, always depending on the strain and its quality.

Growing marijuana in the intertropical zone

Tropics are the region between the Tropic of Cancer and the Tropic of Capricorn. In the intertropical zone there is little variation on the photoperiod throughout the year, while in the equator (latitude 5° N / 5° S) there is a constant photoperiod of 12 hours of daylight and 12 hours of darkness.

Neville's Haze from Mr Nice
Neville's Haze from Mr Nice

As we approach the Tropics there is a maximum variation of one hour during the day, which varies in the calendar depending on whether you are located north or south. For example, in the Tropic of Cancer, the months with more daylight hours (13) fall between May and August, while in the Tropic of Capricorn, it will be between November and February. As for the weather, usually these are warm areas with no frost risk. However, like in the rest of the planet, this may vary depending on altitude.

Given the photoperiod in these latitudes, marijuana can be grown all year round and the plants behaviour will be almost like that of autoflowering strains, i.e. they will go into flowering when they reach maturity, regardless of the current photoperiod.

A hindrance when growing weed is rain, specially during flowering. It is recommended to be prepared for drought and rainfall periods so that we choose the right month to harvest. Direct rain water to plants should be avoided during the flowering period, so using a cover can solve the problem of rain. However, suffice it to say that cloudy skies have an impact on harvests and final yields.  

In the intertropical zone, Indica strains don't grow as vigorous as in areas further from the equator. However, the tropics characteristics are ideal for Sativa strains, local or commercial strains containing tropical genetics such as Acapulco Gold from Barney's Farm, Oldtimers Haze from Ace Seeds and Neville's Haze from Mr Nice, for they will easily adapt to these conditions.

A good way to overcome nature constraints when harvesting marijuana is using a grow lamp in order to grow the plants indoors or in a greenhouse, and taking them outdoors when we wish to make them flower.

Growing marijuana in the southern hemisphere

The southern hemisphere is the area located south of the equator. The day with more daylight hours in the year is 21 December, which is when daylight hours begin to decrease. The shortest day falls on 21 June, coinciding with the winter solstice. On 21 March and 21September, day and night are of equal length. These are called fall and spring equinoxes.

What are the best marijuana strains to grow in Argentina, Uruguay, Chile, Paraguay, southern Brazil, South Africa... 23° to 33° south

In the area comprising 23 and 33 degrees south, the months with more daylight hours are November, December, January and February. Depending on the area, we find subtropical or semitropical climate in all its variations. In most of the area the climate is mild, but because of its montainous landscape there may be serious chances of frost and even snowfall.

White Afghan (23 to 33 degrees south). Depending on altitude, at this latitude, at least two outdoor crops can be produced without artificial light.
White Afghan (23 to 33 degrees south). Depending on altitude, at this latitude, at least two outdoor crops can be produced without artificial lighst.

In warmer areas it is possible to grow two outdoor crops per year. In the winter, the yield will be poorer, which is ideal for experimenting with local seeds. In the summer, selected cannabis seeds are recommended, so you can grow strains such as Nexus from Eva Seeds, Channel + from Medical Seeds and Easy Haze / K13-Haze from Philosopher Seeds . You can get excellent yields in terms of quality and quantity ensuring a great stash of marijuana for the rest of the year.

What are the best seeds for Argentina, Chile, South Africa... 33º to 50º south?

In these latitudes, the four seasons are perfectly differentiated, so there are chances of frost in almost all areas, being abundant in high areas and of course, in areas nearer the South pole.

The ideal time to start growing marijuana depends on altitude and risk of frost - either at planting or harvesting - of the area where it is going to grow. It is also recommended to take into account what strain is planted in a certain month -this will avoid unexpected results regarding the final size of the plant.

Mataró Blue from Kannabia Seeds, late October
Mataró Blue from Kannabia Seeds, late October

For those experienced growers seeking large plants, September and October are ideal months to start growing.  For beginners, a good option is to start growing autoflowering strains, for they are fast and thus avoid salt accumulation or potential pests that may occur in regular seeds during the 5-9 months of their cycle. It is recommended to pay attention to the weather, as frost is still a risk. By covering your plants or moving them indoors at night you can avoid wasting time and money.

If you start growing in November or December, you will avoid problems related to low temperatures. Marijuana plants are nicely developed with 14-15 hours of sun in this season and if the growing conditions are good you will get large plants, whether you are growing them potted or in-ground. These months are also ideal for growing autoflowering strains, such as Maxi Gom from Grassomatic, Deimos from Buddha Seeds and Jack 47 Auto from Sweets Seeds, as they are productive cannabis strains despite being automatic. If Rudelaris genetics are not available, any regular strain will develop well.

Mataró Blue from Kannabia Seeds, late December
Mataró Blue from Kannabia Seeds, late December

January is perfect if you want to grow sativa cannabis strains that do not exceed 250 cm in height. You can also grow indica strains, but they won't get big, although they will be perfectly developed, especially if planted in the early days of this month. Growing autoflowering seeds is recommended - as well as during the mentioned months - even at the end of February, when you can also start growing tropical genetic seeds. In this case,keep in mind the weather conditions when harvesting it.

Mataró Blue from Kannabia Seeds, about to be harvested
Mataró Blue from Kannabia Seeds, about to be harvested

As in the mild area of the northern hemisphere, plants will end their cycle in Autumn. Based on the strain, climate and when you started growing it, the harvest can be between late March and May. Some pure sativa stains can be harvested in June.

Comments in “Growing marijuana basing on latitude” (32)

How many generations would a certain strain (say cm1) need to be grown and breed to acclimate to new growing climate and be a regional variety of the strain cm1? example seeds from cm1 grown in Cali. I take and plant in Southern Illinois. The seeds from these plants I again plant in Southern Illinois. How many generations until I have cm1 Southern Illinois acclimated stabilized variety? It would be different then the original cm1 we got seeds from grown in Cali. but would still be cm1 strain because no crossbreeding just changed growing environment. That should make it a "regional" variation of cm1 or a new strain all together? Southern Illinois cm2. Thanks in advance for any answers.
Tim Alchimia
Hi Babb, thanks for your comment and interesting question. Firstly I'm afraid that I'm not familiar with the strain CM1 so it's hard to assess how much potential genetic variability it has, which would definitely have some impact on the breeding program. Generally speaking, the time it will take to acclimatise a variety to a new environment will depend on a few factors, as I mentioned above there's the genetic variability of the strain used, but a lot will depend on the selections made by the breeder, and more importantly, the omissions, i.e. the plants he rejects. With the proper selection and breeding practices, the process will be a lot quicker. As for the number of generations it might take, it will depend on the factors I've mentioned, but a lot of people seem to think that by taking a variety to F5 (i.e. inbreeding for 5 generations) you can have something unique and uniform. Whether or not it then can be classified as a different strain is another matter. If it shows markedly distinct characteristics from the original CM1 plants then it's possible. Otherwise, it's really just the same thing but bred to suit a different climate. Calling it Southern Illinois CM1 would be fine, in my opinion, you'd be clear about the heritage but also recognising all your own breeding work. I hope that helps to clear things up. Best wishes and happy breeding!
Great thread- Trying to get some info for an outdoor grow in Ecuador. Land race seeds, literally on the Equator but at 10000 feet, so mild Mediterranean climate that is consistent all year long. My question is two fold. How long can we expect the entire growth cycle to be with out light intervention and at what stage would it be best to clone the best looking female plant. Many thanks.
Tim Alchimia
Hi Josema, thanks for your comment and questions. That sounds like you've got a great opportunity for some amazing plants over there, I'm mildly jealous! So the answer to your first question depends on the genetics being grown. Many tropical Sativa plants will flower for 14, 16, 18, 20 weeks or more! From what I understand on the matter, the finishing time is also determined by the time of germination, as the plants are exposed to 12/12 photoperiod they will be triggered to flower when they are mature enough, which apparently can be anything from 2 to 5 months after germination! I've read that when they are planted in the ground it can take longer for them to be triggered to bloom and that the roots being restricted in pots can help speed up the onset of flowering. But as I said before, it's mainly the genetics that will be the deciding factor. If you can find local landrace seeds, and if there's any way you can speak with local growers to find out how they manage their gardens, then their experience will be able to help you far more than I can. To answer your second question, I'd say that taking clones any time before it really starts flowering will be acceptable. You can take clones as soon as the plants have shown sex and they'll root very well and quickly, but by waiting a bit longer you might be able to get a better idea of which is the best plant to choose. I hope that helps, all the best and happy growing!
Hey, great website, truly. I am planning a grow in tropical South East asia, will be naturally a 12 12 light cycle (planning on growing outside under an open greenhouse (sides rolled up) ) I will grow sativa dominant or 100% sativa (if i can get my hands on some) I plan to grow in a no till planting bed, my biggest piece of the puzzle is, do I plant the germinated seed straight into the soil outside and let it go 12 12, or do i grow the seedlings under a CFL and transplant to outside? if so how and when to do this? thanks in advance, love your resource here.
Tim Alchimia
Hi Sam, many thanks for your comment and your kind words, we're really happy you're finding our blog useful. Wow, what a great opportunity, I'd love to be able to grow some amazing Sativas in their natural environment! I suppose that the answer to your question about when to sow seeds will depend on just how big you would like your plants to get and how much you want to be harvesting when they finally mature, which I'm guessing could be as late as December or January. The earlier in the season you sow, the bigger they will become, which is fine if you're growing without any concerns regarding the law or nosey neighbours, or simply space restrictions in your greenhouse! Of course, most of these issues can be dealt with by using pruning and/or training techniques, but you can save yourself a lot of trouble by planning ahead. Sativas and Sat-dominant hybrids are usually very vigorous and tend to stretch a great deal at the onset of flowering, so you really need to take this into account so you don't "overgrow" your greenhouse! As to whether to germinate directly in the soil or start them indoors, well that will mostly depend on how many seeds you've got to play with. If you've only got a precious few, then I'd germinate them indoors and start them under a CFL, gradually getting them used to the sunlight and planting them out after a few weeks of healthy growth, when they'll be a bit more hardy and resistant outdoors. On the other hand, if you've got plenty of seeds then I'd recommend starting them directly in the no-till beds. You may well lose a few seeds or seedlings to pests, but the strongest will survive and what's more, I've always found that starting plants in the same place they are to mature gives me much healthier and vigorous specimens, compared to other plants that I've started elsewhere and transplanted into their final spot. I hope that's some help to you, feel free to contact us with any further doubts you may have. Best wishes and happy growing!
I’m at latitude 44.07 N and 89.28 W How many weeks of flowering do I have? And when does it typically start ? also we tend to receive storms right during flowering time. Greenhouse isn’t a option with nosy people . I usually shake the excess water off.Sometimes it gets hot after the storms in August and early September. What strains are the best for moist and humid. I Know that the flower time depends somewhat on where the breeder created the strain. I like Sativa knowing when they my flowering in general starts will allow me to count back enough weeks on when to force the Sativa to finish in time. Frost is normally oct 15 it can go on either side of that a few days.....-the safest time to set out is April 30 ....-
Tim Alchimia
Hi Corrie, thanks for your question. A lot of the answers you're looking for will depend on local climate and the prevailing conditions but you're at a very similar latitude to myself, so the photoperiod will be very similar. Here, my plants tend to begin the transition into flower around 15th August. Of course, there are some exceptions like fast-flowering cultivars that will begin flowering earlier, and some sativas with tropical heritage that take a lot longer to initiate bloom, but as a general rule for most plants it's the middle of august. As for the flowering time, it totally depends on each plant. It's not so dependant on where the strain was created though, it's got much more to do with the characteristics of the genetics used in each hybrid and where they were originally from. Plants originally from mountainous regions like Afghanistan and Pakistan have developed to flower quickly in the short season when conditions are favourable before the frost arrives, and have morphological characteristics to deal with harsh conditions of drought, wind and extreme heat and cold. On the other hand, varieties that have developed in equatorial or tropical countries where frost is never seen will flower much longer, growing much bigger and their morphological characteristics will have evolved to deal with the different climatic challenges of high humidity, heavy rains and monsoon season. It sounds like you'd definitely be best choosing sativa-leaning varieties, the looser flower structure copes with humidity and mould issues much better than the dense buds of indica-dominant plants. We have a wide range of mould-resistant varieties to chose from, and our blog article on growing cannabis in harsh conditions can offer some ideas of resistant varieties too. From my own personal experience, I can recommend Bangi Haze, Nepal Jam, Orient Express and Congo from ACE Seeds, which are all high-quality sativa-dominant hybrids that finish flowering quickly and should be ready before the frosts hit your area. I hope that helps, all the best for next season and happy growing!
Hi guys. Writing from 12.4634° S, 130.8456° E at sea level here looking for some advice on good easy grow strains for beginners. Auto flower & outdoor would be good but can come inside if need be. We have monsoon/wet season through summer so mould resistance would be a benefit too.
Tim Alchimia
Hey StickyFingers, thanks for your comment and question. Wow, you're certainly at a great latitude for growing tropical Sativas, which are genetically adapted to grow in your part of the world and deal with monsoon/wet season easily. Tropical Sativas can be a challenge to grow for gardeners further away from the equator, but shouldn't be a problem where you are. All you'll need is good soil and patience, as some can take a long time to finish flowering although yields will be huge to compensate for the wait. Personally, I would be looking at Sativas from seed banks specializing in landrace varieties from countries on a similar latitude as you, like ACE Seeds (their Bangi Haze is a fast-flowering and highly resistant Sativa and their Panama is astounding), Cannabiogen, (Destroyer in particular is an easy-to-grow and highly satisfying plant) Seeds Of Africa or Underground Seed Collective. Look for landraces from Central America, Central Africa and South-East Asia, for example Colombian, Congo, Thai, and bear in mind that any hybrids containing afghani, kush, skunk etc. will be more likely to suffer from mould during the wet season while the pure Sativa strains will withstand this due to their later flowering and their more open, airy flower structure. Auto-flowering plants will be fine if you can avoid the wet season, but as a general rule, they don't deal with rain very well. I hope that's helped, all the best for the season ahead, please let us know how you get on. Happy growing!
Thanks Tim. I'm working on it. I'm going to post my solution to anyone growing outdoors in the tropics. Like Tim suggested just 15 mins of light in the night will disturb the dark process or flowering process. Hence enabling the plant to continue in a vegetative stage until it reaches a size/height suitable to the grower. Then simply don't use the light and let our natural 12/12 take over to flowering. For those like me, who need an auto system. Here's what you need. I spent all day on July 21, 2019 mentally trying to set up a solution. Keep in mind everything can be found on Amazon. I don't post links due to the fact, I don't want others to think I'm benefitting off affiliate 1. 10W Solar Panel 12V... 2. A charge controller 3. A 12v rechargable lead acid battery 4. A Digital Timer to automate the process, which will avoid me going in the bush every night. 5.100w Waterproof outdoor grow light or lights so basically the reason these are necessary is due to the fact that, you want to automate the process of giving the plants extra light, but not all night. If you have a light on all night in the bush. It's likely to draw attention from folks who go in the bushes at night. Tim recommended lighting for 15 mins, which is great, but I suppose you can do so for 30mins to 1 to 2 hours. THe solar panel is hooked to the charge controller (prevents the panel from over charging the battery, you will need it since u won't be present to unplug the panel from the battery if you don't have a controller). The battery is then connected to the charge controller. The real automation is the digital timer. It is also connected to the charge controller. So charge controller take power from the panel, to the battery. The battery send power to another channel in the charge controller, which is then released to another connection to whatever product u want to power up. The grow light will then be connected to the timer, and also the charge controller. There will be some wiring involved, but youtube has vids on setting up digital timer. Its something that's common, many use it to automate their chicken houses among other things. Here's a Youtube link explaining how to set up with Panel to charge controller to battery (no digital timer) but you can add with imagination. In this vid, where you see the fan connected would be where the Timer would be connected on that charge controller. Hooking up the Digital Timer has some mid-level home electric skills to it, hence many who purchase don't know how to hook it up. Here below is a vid of an indian guy explaining how it's done. So add the two links together or show them to a friend who does electricity and you'll get set up... The wiring set up starts at 8:40, prior to that he showed how to set the time on the timer for automation which would be our end goal after setting up everything. N.B this vid does not have a Charge Controller. But any friend who does basic electricity home connections for a living can get around this. This is the best vid on wiring the digital timer I've seen on youtube. If Tim says it's ok to post links to the amazon products, then I gladly will. But this is what I came up with, it's the best solution for us who don't sleep in the bush, who got ordinary work life and plant as secondary income. This set up would ensure that we grow indica/sativa photos as large as they grow in the colder climates. The automated light would break the flowering triggered by early darkness in our 12/12 year round climate. Tim said just 15 mins of light on the plants is good enough. I'm thinking of 30mins for extra coverage.
Re-reading your first comment to mine. I now realised you addressed this, and only now seeing that. So just 15 minutes of light is needed to interrupt the plant from flowering. The reason why I wanted a light that comes on automatic n goes off on my timing. Is because I'm doing guerilla growing, it's not close to home. it's like 15 mins walk up a hill, offroad and in the bushes. So I wouldn't have to go every night to the grow spot.
Tim I appreciate your response as it helped me understand my location more when it comes to cannabis. I have a suggestion as I'm trying to work around this. How about if I got solar spotlights, to interrupt the dark period for about 2 hours? They come on automatically as darkness hits, and prevents the plants from going into flowering mode. I have one little issue with the spot lights. I can't find one with a timer. It's not needed to be on all night, as this also could make my grow area be found at night by wanderers. Hence why I'd like a timer that shuts it off after even 1 hour to 2 hours. If the solar spotlights have no timer to shut off, do you think a solar path light would work effectively? They would be on all night, but as we know they're much dimmer than a spot light, not sure if a path light gives off enough light to interrupt flowering when dark falls. This is how I've thought of preventing the flowering stage in my zone, and enable the plants to grow bigger and longer period. If you have a solar powered light you could recommend, I'd gladly check it out.
Tim Alchimia
Hi Brave, thanks for your comment. Personally, I wasn't sure if those path lights would be bright enough for the purpose, so instead of a spotlight I decided to go for some solar-powered LED strips from a local hardware store, which seem to be the perfect compromise - not too bright so as to attract unwanted attention, but bright enough to properly illuminate the plants. Additionally, the flexibility of the strips means it's really easy to adapt them to any situation, fitting them in a way that lights the plants but without letting too much light spill out to the surrounding area. Although, as you say, a solar lamp with a timer would be the best option, I'm still looking for one, no luck so far I'm afraid! All the best of luck for the season and happy growing!
Susi sorensen
I started outdoor clones in San Diego June 12, then I moved them to north of San Francisco July 5. They look like they are trying to flower and vegetative growth is minor, not much branching. Was this an effect of moving them to a more northern latitude. They are mostly kush varieties
Tim Alchimia
Hi Susi, thanks for your comment and question. Moving them further north at this time of year shouldn't provoke them to start flowering because, in theory, the days are slightly longer the further north you go, until the autumn equinox anyway. Is there any chance that the plants were in darkness for more than 12 hours at any point during the move northwards? If so, then that could be the cause of the problem, otherwise, I can't really think of any reason they'd begin to flower, apar from it sometimes happening if the plants are rootbound and are long overdue a transplant. Some particularly sensitive varieties can begin flowering as a reaction to stress, in this case, possibly the stress of the move could have caused it. Of course, it's also possible that the plants are very early-flowering varieties, and that beginning the bloom phase this early is perfectly normal for the genetics you've chosen. There are plenty of variables, it's difficult to know what could be the root cause, but either way, I hope the problem resolves itself and that you end up harvesting a nice crop of buds. All the best and happy growing!
How long would a sativa veg in the tropics?
Also I'd like some understanding for my zone. In the tropics, the long grow period from April/May to Sept/Oct, we call it long crop where I live. The ideal strains are Sativa photoperiods. Can description that says "Mostly Sativa" work also? Suppose I decide to buy some sativa photoperiod strains. Then I plant them in September/October, will they flower as autos do, due to shorter light days leading up to Dec/Jan? Or will they stay in veg stage till next September harvest? Early Maroc strain, is it only for July to August harvest? Can it be used in my Tropics zone any time of the year? Also from my understanding, In the Tropics, Indica photoperiods cannot be grown outdoors for a long vegetative growth. I first have to either grow indoors or in a tent with long light cycle until desired growth is reached. Then I can take it outdoors to begin flowering. Basically indica for outdoors was meant for areas 25 degrees and beyond, north or south of the equator. Just clarifying if I understood correctly.
Tim Alchimia
Hello Brave, many thanks for your comments and questions, I'll try and help you the best I can. As you've already found out (and yes, you've understood it correctly), the critical night length to trigger flowering can vary depending on the genetics chosen. The Indica varieties are from areas of the world with long days and short nights in summer, and vice-versa in winter, so at your latitude, they began to flower almost as soon as they sprout. Now your plants are flowering they will continue until mature, so yes, you can effectively harvest them like autos. If you're growing purely outdoors without any electricity then Sativa genetics are probably your only option. While seed banks may classify a variety as being Sativa-dominant, that doesn't mean it will match everyone's idea of what a Sativa is, or perform well in tropical zones. One frequently sees OG/Cookies/Diesel etc. labelled as mostly Sativa, which I think can be a little misleading. Another thing to remember if you're growing a Sativa-dom hybrid from seed is that you'll find some plants are more Indica-leaning, with others more towards the Sativa side. For your latitude I'd recommend seed banks like ACE Seeds,, USC and Seeds Of Africa for good quality pure Sativa and mostly-Sativa hybrids based on landrace genetics from tropical zones. I'm not sure about sowing them in September though, I guess a lot would have to do with local seasons, I don't know if there's a rainy season or not. Personally, I would sow as soon as humanly possible so that the plants can grow to a reasonable size over the summer and give a decent harvest in December/January. Regarding the Early Maroc, in your climate and with the natural outdoor photoperiod, you could be flowering pants like that all year round if weather permits. If you've got lots of seeds, you can do a Sea Of Green (SOG) type grow with lots of small plants giving you one main bud each. If, however, you want the plants to grow bigger before they flower, you could give them some additional illumination to extend the day or break up the night time. This would keep them in vegetative growth until you felt they were a good size to begin flowering, at which point you'd simply remove the supplementary lighting. If you don't have mains electricity another option would be to use a solar panel to power low-energy LED lights. Switching the lights on for 15-30 minutes in the middle of the night can be enough to keep the plants from flowering. I hope that's answered everything, all the best for the rest of the season and happy growing!
Tim I came across this page looking for solution. I planted photos strain of Afghan Kush and also White Widow. My countries latitude is 15° north. Clearly in the tropics. They have begun to flower to my dismay. I was hoping for a long veg grow b4 flowering. Will the flowering phase last up till Sept or will I have to harvest like the autos. To be clear, it means I need to plant on sativa photos for my region? here I was hoping to shoot for a 1lb a plant with a long veg. So disappointed.
Tim I'm trying to figure out what I might expect with the length of vegetative and flowering cycle times. I'm in central Mexico, 22 degrees lat, 5,000 feet up in the Sierra Madras mountains. Climate is classified as high dessert. Daylight varies very little, averaging 12 hours a day with maybe a swing of one to two hours summer to winter. Temperatures are very moderate, averaging 70 degrees. Lots of sunshine. I planted some seeds from a friend two months ago. Variety unknown. They're up about 18 to 24 inches now. Its now the beginning of June. What might I expect for the end of vegetative growth and the start and end of flowering? Is there an optimum time of the year I should be starting seeds? TIA SunFan from Lake Chapala, Mexico
Tim Alchimia
Hi SunFan, thanks for the question. A lot depends on the genetics you're growing, for example, an Indica variety would most likely flower straight away outdoors with that kind of photoperiod, whereas a pure Sativa that's adapted to your latitude would grow for the whole summer and begin to flower as autumn approaches. By the sounds of it, the seed your friend gave you must be Sativas, because if not, and they're Indicas, I think they'd have begun to flower before now at your latitude/photoperiod. In this case, you can probably expect them to get quite big over the summer, this is the peak period for plant growth. I'd imagine that towards the middle/end of August, the plants will begin to flower and hopefully be finished at some point before Christmas! Without knowing the genetics, it's really difficult to predict when a plant will be ready for harvest, but as long as you protect them from frost and the weather doesn't turn really cold and wet they will be fine, and you'll need to pay close attention to the colour of the trichomes as they mature. This is all explained in another of our blog posts "When to harvest according to trichome ripeness". As for an optimum time of year to start seeds for the outdoors, it mostly depends on a combination of factors, such as the genetics, the size of plants we want, and most importantly the climate in which we grow. If a grower in a warm climate wants large plants, he will germinate seeds in January and grow them up over spring with supplementary lighting to ensure huge plants by the end of summer, whereas someone in a northern country who doesn't want their plants to get too large can start seeds in mid June and still get a decent harvest without the plants growing too large. I hope that's helped to clarify things, all the best for the season ahead, good luck and happy growing!
Hey there, this is a very nice article and it is very helpful thank you!! I live in the tropics located 22.3° N, 73.18° E This year I am planning to grow during September but I am confused whether the plants will flower or will it continue its vegetative growth once it matures. Maximum sunlight received from September to February will be less than 12 hours, somewhere around 10 hours. But after the winter solstice that is 22 December will my plants still flower or continue vegging? So, my question is should I grow feminized seeds during this period or should I grow autoflower?
Tim Alchimia
Hi Tan, thanks for the question. If the daylight hours are less than 12 or 13, then the plants will continue to flower, no question. As long as the conditions are warm enough then you'll be able to grow some amazing long-flowering Sativas. Autoflowering plants are not designed for your latitude, they're for much further north where plants need to flower during the long days of summer to avoid the early autumn cold and rain. Where you live, plants can flower pretty much all year round, and you'll be best planting Sativas which will give you the best vegetative growth before flowering. Indicas and Indica-dominant hybrids will stay very small and produce very little as the will begin flowering as soon as they are mature, behaving pretty much like autoflowers do. Sativas, however, can be germinated under 12/12 photoperiod and still easily reach 7ft tall by the time they finish! I hope that's cleared things up, all the best and happy growing!
James P Yale
Hello Tim: nice website ya got about some outdoor grow recommendations for southwest Florida?..
Tim Alchimia
Hi James, thanks for the kind words, and for the question too. Really the best thing is to talk to local growers and see what they're planting and how they do it, but I also realise that in non-legal states this isn't as easy as it sounds, so I'll help the best I can. I don't know too much about growing conditions in your area, but I do know that it's generally fairly humid there and that mold is a very real risk. We have a post all about, but it's really aimed at more northerly growers, whereas you're quite far south so you have more options open to you. so for outdoor growing, you'll probably be best with something very Sativa-leaning, almost pure. The looser, more airy floral structure will greatly help to keep botrytis/bud-rot to a minimum, and I don't imagine you suffer from frosts in autumn, so your flowering season will be easily long enough for these varieties. Personally, I'd be looking at varieties based on landrace strains from the general area/latitude, so start with Central American and Caribbean varieties like,,,,, etc. and the various containing them can also offer another interesting option. I hope that's helped you out, if you need any more advice, don't hesitate to ask. All the best and happy growing!
hi what are the best strains to grow outdoors in new zealand ? cheers
Tim Alchimia
Hi harlz, thanks for your question. So I can help you, can you tell me roughly which part of NZ you're growing in? There's quite a difference in seasonal conditions between the top of the North Island and the bottom of the South Island, which would greatly affect your choice of variety.
well, this make sense of why my plants started to flowering so soon(intertropical country), well, next time I will try in the "dry season", next time I will try an hybrid indoor/outdoor, get some lights and run them for 3 to 4 hours when it get dark so they can grow a bit then turn them of to flower, also what strains you guys recommend for intertropical countries? also there is a chance you guys ship to Costa Rica? thanks
Hello.just want to know if I plant in August in Sydney Australia when could I look at Finishing .I have MBs xwhite widow .c99's still a little cold start them in greenhouse and plant out .never grown out of season before.and would they stretch alot..thanks your knowledge would be greatly appreciated......
Tim Alchimia
Hi Joey, thanks for your question. At that time of year there are only 10-ish hours of daylight in the day, so the plants would begin flowering as soon as they're mature, usually after growing 4-5 sets of leaves. They won't grow very big with so few hours of light, and they oughtn't to stretch too much either. If you want to give them a better start I'd recommend starting them indoors and growing them under lights for a few weeks, letting them get to a bigger size before putting them in the greenhouse to flower. All the best with your grow, happy planting!
What strains do you recommend for the intertropical zone around the Tropic of Capricorn. Would sativa dominant strains veg longer
Tim Alchimia
Hi Mic, thanks for your question. Wow, how lucky you are to grow in those latitudes, you'll be able to grow some amazing tropical sativa genetics there for sure! Firstly I'd look at landrace varieties from countries that have a similar latitude, here at Alchimia we stock two highly reputable seed banks that work with landrace sativas, firstly ACE Seeds who have some excellent pure varieties from Panama, Honduras, Ethiopia, and Malawi as well as some very interesting sativa hybrids like Zamaldelica, Golden Tiger, Old Timers Haze or Tikal. Then we also have Cannabiogen with their Colombian Red or Destroyer (Mexico x Colombia x Thai). Other varieties worth mentioning are Zambia from Tropical Seeds, Double Zamal from USC, Mangu Karot from French Touch. Those are just a few suggestions, but by searching our shop for "landrace" or "sativa" you'll see a whole range of options. Have fun deciding! All the best and happy growing.
Hi I would like to grow Autos outdoors, im located in 31N 32E Can you recommend best indica/sativa auto strains for this climate Many thanks
Dani Alchimia
Hi Alexander, With your climate, as long as plants have enough irrigation they'll be ok. Most of the automatic strains in our web will adapt perfectly to your climate and location. That being said, I'd recommend you Fraggle Skunk Auto if you want high yields, Sweet Nurse Auto if you want CBD and a more medicinal effect, or OG Kush Auto if you want a tru intense effect. Hope it helped!
Thanks for the fast and helpful response! So, if I understand correctly, it should be all year like "flowering" hours, is that it? I would BE able to use photoperiod and clones for quick harvest and not big size...Or vegetate indoors then take outside? This is good news to maybe not depend on autos. Light pollution is a concern however... But this info should push me to try a photoperiod to see how it turns out for a test.
Dani Alchimia
Hi Isleno, I'd definitely try some photoperiod strain and see how it performs. Most people I know who live in Canaries use their outside yard as a flowering room, they know plants will start flowering as soon as they're taken outside during - almost - all year, so they grow them indoors and take them outside when they have the right size. Light pollution may be a problem, although I can perfectly read a newspaper at night in my yard next to my flowering plants, they're less sentitive to it than we normaly think. Hope you'll be lucky!
Hi, very helpful article, thank you very much! I am at 32° 38", so close to canaries, what advice would you give me on grow schedule and my best bets? Weather is also rather close to canaries: no frost ever, no negative temps, maybe aniversário average humidity.... would love some info for future planning anos possibilities. For the moment I have a small terrace that gets direct sun all day however size is a big concern unfortunately so I'm thinking of very small autos to be safe... :( Less than 1 m high is the maximum at the moment, any specific advice on that for not a Pure indica? Would rather have a sativa dominant but doubt it would be possible? Thanks in advance!
Dani Alchimia
Hi Isleno, You have a nice weather to grow cannabis, although in your latitude plants don't grow much and start flowering as soon as they reach sexual maturity (3-4 weeks). If you're interested on mostly Sativa autos, I'd definitely try Philosopher Seeds Cheesy Auto, Sour Ryder ASB or Dinafem's Amnesia XXL Auto. Hope it helped!
Thanks dani! One more question. My mother plant snap ped due to wind, I taped it up in hopes of re generation. Is that a good idea? Or should I cut my losses and take clones?
Dani Alchimia
Hi freddy, It'll probably regenerate, cannabis is a very tough plant, although I'd take a couple of clones if possible, just in case! ;)
juan ochoa
Hello, I would like suggestions on strains for tropical climate outdoors, exactly at 11 latitude, i am growing a seedling with 60% critical mass 40% white widow and its growing well despite the cloudy days we have had since its germination. i am also concerned about mold because of high humidity almost all year round... thank you
Dani Alchimia
Hi juan, Since you probably won't have problems with cold temperatures, and taking into account that you grow in an area with high environmental humidity, I'd try hybrids with Sativa dominance. Sativas are more resistant to fungi than Indicas, which often develop more compact buds and are more sensitive to mold infections. All the best!
We just passed recreational and legal grow for up to 12 plants in Massachusetts. Final frost is first week of April, we get almost no rain all summer and a peak temp right around 85 F on Cape Cod. We make it to 12/12 right around mid/late October. 42parallel. I would love some input on ideal strains for this area. Thanks!
Hi! What strains can you suggest that suit the climate in Central America, especially for a newbie grower?
Dani Alchimia
Hi Artemis2318, Doubtless, and because of the natural photoperiod of your area, I'd try Sativas or mainly Sativa hybrids. This type of plants grow much more vigorous and taller than Indicas, and are perfect for your climate conditions. Hope it helped!
How are you any suggestion on outdoor plants for Ireland I have a greenhouse will autos work thank you any help will do
Dani Alchimia
Hi David, Autos will do in Ireland, especially in a greenhouse, although you should grow them during the warmest months of the year. Photoperiod strains with early flowering could also work, like Early Maroc from Philosopher Seeds or C-99 from Female Seeds. Best of luck!
If i started my plants in late june in e colo just east of mountains how big will my plants get outside will they bloom in sept?
Dani Alchimia
Hi Scubasteve68, Well, it depends on several factors: -Pot size (if you want big plants plant them directly in the ground) -Daylight hours (the more direct sunlight they have, the more they'll grow) -Nutrients (the more accurate the feeding, the more they'll grow) -Genetics (mostly Sativa strains grow much taller and wider than Indicas). Depending on these factors, you plant can reach 1-2 metres in height, approximately. All the best!
Hello, im moving to the canaries soon, wanna still make the closest window on March, what do I need? I wanna grow different strains outdoors and maybe some indoors just to know how and try them I like Sativa strains, i prefer the happy/energetic mood, We r a few friends and we will plant enough ? Best regards, Nizar
Dani Alchimia
Hi Nizar, Basically, growing in the cannaries is almost like growing autoflowering strains. Unless it is midsummer, when they may grow for some extra weeks, plants are usually ready to harvest after 3-5 months from seedling (depending on strains, Sativas will take longer). Here you have a list of some of the best Sativa hybrids on the market. Since plants start flowering at almost any time of the year, many growers grow them a little bit indoors and put them outdoors when they have the desired size to begin flowering. The canaries are affected by sirocco coming from Africa, so perhaps you need to protect your plants from this hot and dry wind, otherwise they could wilt. Hope it helped!
We're is the best reliable seed bank and will thay ship anywhere in the U.S.
Thank you
hi, i browsed through your article searching for information that will guide me through a plantation process whereby im interested in growing a marijuana plant that, its height wont protrude higher than 30cm and will produce kush that has a less tiring effect. my ideal location is tropic of capricorn, southern africa. can you please provide information? including of course how to get a hold of the seeds or how to produce them at my own peril. thanx :)
Dani Alchimia
Hello Motlotlegi, If you are looking for a strain short in size, you should look for pure Indica plants or autoflowering strains. The problem is that most indicas have a narcotic/sedative effect, which is not what you want. Thus, I think you should look for short, mostly sativa autoflowering strains , which won't grow at all like normal strains and will produce an uplifting/stimulating effect. Unfortunately, we are not shipping our products to Africa, so we can't help you getting these seeds. We hope to publish a post about the basics of breeding in a few weeks, so you can start thinking about making your own seeds. Thanks for your confidence, Best vibes!

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