Accuracy and latitude of Greenhouse starin harvest month outdoors

[PHDin420]

I am an outdoor grower located at 42* latitude north which is at the same latitude as northern Spain, the northern California/Oregon border and about 5* north of the Hindu Kush region.

 

On the Greenhouse website, they have a chart with all of their strains that gives an estimate of harvest time outdoors that can be seen on the Greenhouse website, under the research and development icon under GreenHouse strains statistics.

 

I am looking to get an opinion of the accuracy of these estimates and at what exact latitude they are for. I know it says for the northern hemisphere but harvest times can be drastically different from 25*N to 45*N since the longest days are longer the further north you go and the date at which a plant will begin to flower is later, because the daylight hours don't get short enough until later in the year. I will give an example of three different latitudes north, the length of the longest day on June 21st and the date daylight is 14 hours or less, which I have found almost all strains will start to flower at when grown indoors.

 

28* latitude N - longest day 13.58 hours - always below 14 hours

 

35* latitude N - longest day 14.31 hours - date daylight is 14 hours long July 27

 

42* latitude N - longest day 15.18 hours - date daylight is 14 hours long August 12

 

61* latitude N the Matanuska Valley in Alaska - longest day 19.22 hours - date daylight is 14 hrs. Sept. 3

 

Now I know that every strain will adapt to the natural light cycles at the latitude it is grown in and the amount of light on the date it will start to flower will be different but only, in my own personal experience, if the daylight is 14.5 hours or less.

 

I'm looking for strains that will finish preferably no later than Sept. 20th at 42*N and definitely no later than October 10th because the weather conditions here are both moist and cold but as long as you harvest before Sept. 20th you won't have any problems with mold or frost/freezes because it is still very warm here, even though 3 weeks later there could be snow on the ground.

 

In my experience at 42*N most hybrid strains will start to flower by August 1st which has 14.26 hours of daylight but then like most strains they take 8-10 weeks to finish, which puts them somewhere between October 1 and 14th. I have grown a few strains that actually started flowering in the last weeks of July with 14.5 hours of daylight and when they did, they were finished on September 20th. So if this helps anyone that has grown one of these strains indoors and you know it will flower with 14.5 hours of light, than please let me know.

 

So what I am looking for is exactly what latitude the estimates in that chart was estimated for, if someone can answer that. If you have grown a strain on the list outdoors and your harvest time was different than it states, can you please tell me the strain name, degree latitude north it was grown at and when you planted and harvested.

 

I am also interested in any strain recommendations, from either Greenhouse Seeds or here from Strainhunters that may fit what I am looking for, if in your experience, you grew it outdoors and it finished before the estimate on the chart. If you have, please include the strain, latitude grown at and date planted and harvested.

 

Thanks for reading this long post and I hope it will help many others. I hope to return the favor by hopefully answering some questions using my own knowledge.

[PHDin420]

No one from greenhouse or anyone else can comment?

[Tokage]

I´m so sorry for the late answer(or lack of answers)
Im no expert in latitude and longitudes but i will bump this thread for you. If you do not get any good answers in a few days i will find the answers for you  
 

[PHDin420]

Thanks for the reply. I couldn't post the link to their page when I first made this post so here it is for easier reference;

 

http://www.greenhouseseeds.nl/shop/green-house-strains-statistics.html

 

I'm pretty sure GH would have picked a specific latitude for those estimate's but any info at any latitude can also give you more information as well as the plant's genetics. To give some quick examples so others can get an idea is that some equatorial strains that grow in lower latitudes where the longest day on the summer solstice doesn't get above 13 hours of daylight, can't really be grown at a higher latitude because they will not start to flower until roughly 13 hours of light, which gets further out from the solstice as you get higher in latitude as I briefly explained in my OP. Those strains are the ones in yellow at the bottom of their chart that have harvest estimates from mid October into November and most are sativa dominant. The strains higher up on their chart are bred from landrace strains located at higher latitudes where the days are longer on the summer solstice(example's in my OP). These strains will usually begin to flower with more and in some cases a lot more daylight so they will finish outdoors before they weather gets cold as it does at higher latitudes.

 

If someone can tell me from personal experience a particular strain they grew on that list outdoors and the latitude it was grown at I can figure out the harvest date estimate for another latitude by looking at a spread sheet I have that will show the amount of daylight at any specific latitude for every day of the year. So even if we can get an answer from GH on the latitude those harvest estimates are for, if anyone also has personal experience with any of them and can give me the latitude they were grown at, I can make a post with my spread sheet that anyone can use to make their own estimate of when a strain should be ready for harvest at their latitude.  

[Tokage]

Still no answer eh, well if you go to GHSC seed page https://shop.greenhouseseeds.nl/ Look at the flower info and see what suits you. You will find veg/flower time plus optimum conditions for each flower. From that you will have an easy time to puzzle out the best strain for you.
I hope i was to some sort of help.