Can I 24hr veg, put outside after summer solstice to force flower for multiple crops?

Ive been looking for information on force flowering plants without having to cover and uncover them everyday.

I found an article that explains how to do just that and harvest multiple times during the outdoor season in the northern hemisphere pretty well, I wrote my own notes and figured this could help people feel a bit more in control of growing outdoors.:

Normally when growing outdoors we only take advantage of the best period of the year. Marijuana plants grow (VEG) during Spring and early Summer: March, April, May, June, and July. Then typically start flowering the end of Summer (August) and finish flowering in Autumn (September, October, November)

Though it is possible to perform several outdoor crops per year!

alchimiaweb.com says:
Plants that have been under an 18/6 or longer VEG cycle can start flowering automatically when placed to the shorter outdoor light cycle. (I was thinking 24hr veg would be necessary to achieve this. I still plan to veg 24hr for ease.)

Many growers use small pots indoors and transplant to bigger containers when they are placed outdoors. Using a quality root stimulator during the first two weeks outdoors helps the plant to develop a nice rootball needed to achieve abundant yields. During this short period, also make sure that the plant has all the Nitrogen it needs for a lush pre-flowering "stretch" phase.

alchimiaweb.com says:
The critical date for cannabis plants grown (VEGGED) indoors and force flowered outdoors to be finished flowering is when the days reach around 14.5 hours of daylight.

Plants that we put outdoors during January, February, March can stop flowering and begin growing (VEGGING) again – since the daylight hours are increasing.

For me at 47N, estimated May 1st is the deadline for force flowered outdoor plants to be finished. Thats when my days are 14.5hrs of daylight and increase everyday until 16hr daylight on june 21st, then begin decreasing a little each day.

Alchimia is based in Vilamalla, Spain at 42N, this is the same lattitude as the Oregon and California border for reference. May 14th Is the estimated deadline for early Spring force flowered outdoor plants to be finished at this lattitude.

Los Angeles at 34N, June 21st is the longest day of the year at 14.5hrs and then the days begin getting shorter, so you can probably force flower year round.

For Early additional harvests in Spring (march, April, until middle of May latest):

fluorescent or CFL lighting is enough to grow (VEG) autoflower seeds or cuttings for a few weeks.

If we start autoflower seeds or cuttings at the end of the last year (December) or beginning of the new year (January) we can have nicely developed plants in February. Perfect for an early Spring end of March/early April outdoor harvest.

Plants go outdoors during January, February, March.
(Your climate, grow space, and mj strain cold/wet hardiness dependent)

Important information from the comments in the article:

March 18, 2016 andy asked:

"I stay in northern Cali I moved my plants from 24 hours of light to my greenhouse march 7th to flower my question is will I haft to light dep to keep them from revegging I plan to harvest first week of may?"

March 22, 2016 Dani Alchimia replied:

"It will mostly depend on the strains you’re growing: I’ve had mostly Indica hybrids that were still flowering by the last weeks of may, while Sativa hybrids often tend to reveg earlier, by early May."

March 25, 2016 andy replied:

"The strain is strawberry cough its a 7 to 8 week flower time. Any advice?"

March 29, 2016 Dani Alchimia replied:

"Pretty fast strain! I would bet you will harvest it without problems."

Planting Time For Large Full Season Outdoor Plants:

Ideally you want to move your large full season plant starts outside to begin veg ASAP after the daylight hrs increase to more than 12 hours per day and climate allows it.

For me at 47N lattitude large full season plants *can* be planted/moved outside as early as the 3rd week of March.

at 42n lattitude (Vilamalla, Spain and the Oregon/California Border) and 34N lattitude (Los Angeles) large full season plants *can* be planted/moved outside as early as april 1st.

These plants will typically start flowering the beginning of August and finish at the end of September/end of October.

For Late Additional Harvests In Autumn (September, October, November), and even later if your climate allows:

We can start seeds or cuttings at the the beginning of July so we can have nicely developed plants to put out in August through September.

The nice thing about Autumn harvests is that we don’t have to worry about the plants trying to reveg since the days are getting shorter instead of longer.

A greenhouse is recommended to endure the weather for a harvest in October/November/December.

source: https://www.alchimiaweb.com/blogen/off-season-marijuana-crops-outdoors/

More Great Reference Material:

Silverback's Start Flowering Indoors And Move Outdoors To Finish Thread:

https://www.icmag.com/ic/showthread.php?t=86345

Silverback's Forced Outdoor Maturation Thread:

https://www.icmag.com/ic/showthread.php?t=82213

Silverback's Daylength and the appearance of first flowers Thread:

https://www.icmag.com/ic/showthread.php?t=94643

Silverback's In-Out/ Transition Schedules and Lighting Thread:

https://www.icmag.com/ic/showthread.php?t=107987

Silverback's This years outdoor clone program Thread:

https://www.icmag.com/ic/showthread.php?t=112265

Silverback's Show Your Truly Early Finishers Thread:

https://www.icmag.com/ic/showthread.php?t=98365

updated

^Thanks for adding that link, more good information on force flowering by starting 12/12 indoors and moving plants outdoors to finish.

Clones can also be rooted under a 12/12 light cycle, This might make your force flowered clones finish flowering sooner.

This may work for certain indica plants. It will not work for hardcore sativas. Some sativas will not flower much with 12+ hrs of light. I am going to put Hunk clones out this year to see how they do at 40 degrees.

Ibechillin said:

Ive been looking for information on force flowering plants without having to cover and uncover them everyday.

I found an article that explains how to do just that and harvest multiple times during the outdoor season in the northern hemisphere pretty well, I wrote my own notes and figured this could help people feel a bit more in control of growing outdoors.:

Normally when growing outdoors we only take advantage of the best period of the year. Marijuana plants grow (VEG) during Spring and early Summer: March, April, May, June, and July. Then typically start flowering the end of Summer (August) and finish flowering in Autumn (September, October, November)

Though it is possible to perform several outdoor crops per year!

alchimiaweb.com says:
Plants that have been under an 18/6 or longer VEG cycle will start flowering automatically.
(I was thinking 24hr veg would be necessary to achieve this. I still plan to veg 24hr for ease.)

no,
If you put a clone in a indoor room or gh under 24 hour light on april 1st for 30 days, then put outside may 1st with just natural light no supp, it will start to flower, but only for a couple weeks max, it gets confused... then it will reveg, and you end up with a nasty looking shrub full of single blade fan leaves and flower bracts all up and down the nodes. Then the plant will go back to veg and start throwing 3-5-7-9 ect blade counts, you end up losing many weeks of growth and the plant goes through a lot of stress, of which is avoidable with supplemental lighting in the garden......however if you are growing from seed, you shouldnt ever grow seed for full term outdoors under 24 hours of light, at the most 18/6, but ideally you just start seed outside in a small hoop or gh or coldframe, seeds, unlike clones, do not need supp lighting to avoid flowering , even if you plant them in early march.


Many growers use small pots indoors and transplant to bigger containers when they are placed outdoors. Using a quality root stimulator during the first two weeks outdoors helps the plant to develop a nice rootball needed to achieve abundant yields. During this short period, also make sure that the plant has all the Nitrogen it needs for a lush pre-flowering "stretch" phase.

For Early additional harvests in Spring (march, April, until middle of May latest):

fluorescent or CFL lighting is enough to grow (VEG) traditional seeds or cuttings for a few weeks.

If we start seeds or cuttings at the end of the last year (December) or beginning of the new year (January) we can have nicely developed plants in February. Perfect for an early Spring end of March/early April outdoor harvest.

No, You would never want to start seeds for a full term garden earlier than feb, march/april is ideal. Clones no need to take earlier than April 1st. A clone taken april 1st will not only catch up in size and potential to any clone taken before then, but it will be more vigourous, and healthier, since it is many months younger

Plants go outdoors during January, February, March.
(Your climate, grow space, and mj strain cold/wet hardiness dependent)

alchimiaweb.com says:
The critical date for cannabis plants grown (VEGGED) indoors and force flowered outdoors to be finished flowering is when the days reach around 14.5 - 15 hours of daylight.

Plants that we put outdoors during January, February, March will start revegetating (REVEGGING) = stop flowering and begin growing (VEGGING) again – since the daylight hours are increasing.

Alchimia is based in Vilamalla, Spain at 42N, this is the same lattitude as the Oregon and California border for reference. May 14th Is the deadline for early Spring force flowered outdoor plants to be finished at this lattitude.

(For me at 47N, May 1st is the deadline for force flowered outdoor plants to be finished. Thats when my days are 14.5hrs of daylight and increase everyday until 16hr daylight on june 21st, then begin decreasing a little each day.

Los Angeles at 34N, June 21st is the longest day of the year at 14.5hrs and then the days begin getting shorter, so you dont really have a deadline for the early Spring force flowered plants.

Important information from the comments in the article:

March 18, 2016 andy asked:

"I stay in northern Cali I moved my plants from 24 hours of light to my greenhouse march 7th to flower my question is will I haft to light dep to keep them from revegging I plan to harvest first week of may?"

March 22, 2016 Dani Alchimia replied:

"It will mostly depend on the strains you’re growing: I’ve had mostly Indica hybrids that were still flowering by the last weeks of may, while Sativa hybrids often tend to reveg earlier, by early May."

March 25, 2016 andy replied:

"The strain is strawberry cough its a 7 to 8 week flower time. Any advice?"

March 29, 2016 Dani Alchimia replied:

"Pretty fast strain! I would bet you will harvest it without problems."

Planting Time For Large Full Season Outdoor Plants:

Ideally you want to move your large full season plant starts outside to begin veg ASAP after the daylight hrs increase to more than 12 hours per day and climate allows it.

For me at 47N lattitude large full season plants *can* be planted/moved outside as early as the 3rd week of March...with a heated greenhouse probably.

at 42n lattitude (Vilamalla, Spain and the Oregon/California Border) and 34N lattitude (Los Angeles) large full season plants *can* be planted/moved outside as early as april 1st.

These plants will typically start flowering the beginning of August and finish at the end of September/end of October.

For Late Additional Harvests In Autumn (September, October, November), and even later if your climate allows:

We start seeds or cuttings at the the beginning of July so we can have nicely developed plants to put out in August.

The nice thing about Autumn harvests is that we don’t have to worry about the plants trying to reveg since the days are getting shorter instead of longer.

A greenhouse is recommended to combat the weather for a harvest in October/November/December.

source: https://www.alchimiaweb.com/blogen/off-season-marijuana-crops-outdoors/

Click to expand...

Not to be rude but ur wrong, and i hope others dont take your post for fact.

I appreciate you letting me know there could be misinformation in my post, though How can a clone be younger? I was under the impression clones are the same age as the mother plant they were cut from, hence already being sexually mature. This Was posted by MountainBudz may 17th @ 12:43am.

MountainBudz said:

Clones are usually always sexually mature. I have taken clones vegged on both 24/0, 20/4, and even 18/6 light cycles and threw them out in middle of may when we are receiving 14 hours plus sunlight and they always went straight into flower and took forever to revert and some didn't. That happens with clones 95% of the time when I used to try it. So strain dependability comes into play as well as the most important factor, them being sexually mature.

I then started throwing them out after or at the end of the first week in June and never had an issue regardless of the current light cycle they were in, usually 24/0 or 18/6 in my experience.

Basically to simplify what I am saying here, I can sit clones out right now and they 95% for sure will start flowering, this is from experience. However, I can sit plants from seed out before reaching sexual matuirty even at 3 to 4 weeks in, as long as no sexual expressions are showing and be golden, they will continue vegging with zero issues. So in my situation, having plants even being from seed, that are 2 to 4 months old, that is no different than sitting out a clone, same situation even though they are from seed, they are sexually mature.[

Click to expand...

Ibechillin said:

alchimiaweb.com says:
Plants that have been under an 18/6 or longer VEG cycle will start flowering automatically.
(I was thinking 24hr veg would be necessary to achieve this. I still plan to veg 24hr for ease.)

Click to expand...

Ibechillin said:

For Early additional harvests in Spring (march, April, until middle of May latest):

If we start seeds or cuttings at the end of the last year (December) or beginning of the new year (January) we can have nicely developed plants in February. Perfect for an early Spring end of March/early April outdoor harvest.

Plants go outdoors during January, February, March. (YES APRIL/May is too late to start force flowering plants because they will reveg in may, i said nothing about putting plants out in April or May to force flower, The first example you gave in red referenced putting plants outdoors IN APRIL.)
(Your climate, grow space, and mj strain cold/wet hardiness dependent)

Click to expand...

Ibechillin said:

alchimiaweb.com says:The critical date for cannabis plants grown (VEGGED) indoors and force flowered outdoors to be finished flowering is when the days reach around 14.5 - 15 hours of daylight.

Plants that we put outdoors during January, February, March will start revegetating (REVEGGING) = stop flowering and begin growing (VEGGING) again – since the daylight hours are increasing.

Alchimia is based in Vilamalla, Spain at 42N, this is the same lattitude as the Oregon and California border for reference. May 14th Is the deadline for early Spring force flowered outdoor plants to be finished at this lattitude.

Click to expand...

The second piece you wrote was right underneath the headline: For Early additional harvests in Spring (march, April, until middle of May latest):

theJointedOne said:

No, You would never want to start seeds for a full term garden earlier than feb, march/april is ideal. Clones no need to take earlier than April 1st. A clone taken april 1st will not only catch up in size and potential to any clone taken before then, but it will be more vigourous, and healthier, since it is many months younger

Click to expand...

I said nothing about starting seeds or cuttings for full season plants earlier than march/april, you insinuated i did...Notice the headline, That is ideal time to start seeds for plants you plan to force flower and hopefully have finished by May. There is a piece of the post i wrote further down that says to start seeds/cuttings for full season plants in March/April.

Ibechillin said:

Planting Time For Large Full Season Outdoor Plants:

Ideally you want to move your large full season plant starts outside to begin veg ASAP after the daylight hrs increase to more than 12 hours per day and climate allows it.

For me at 47N lattitude large full season plants *can* be planted/moved outside as early as the 3rd week of March...with a heated greenhouse probably.

at 42n lattitude (Vilamalla, Spain and the Oregon/California Border) and 34N lattitude (Los Angeles) large full season plants *can* be planted/moved outside as early as april 1st.

These plants will typically start flowering the beginning of August and finish at the end of September/end of October.

Click to expand...

I do agree that the plant is theoretically as old as the original mother plant.

Blue dream clone must be about 18 years old or so...however you think a fresh cut clone off a healthy mom of Blue Dream is going to act the same as a actual 18 year old Blue dream plant that somehow has been kept alive on the same root stock?

So yes the plant is sexually mature, in a sense it is not in limbo between male and female.

If you took a clone in January, took great care of it best you could ect..
And you had a fresh clone off a fresh mom April 1st...

and put both out in exact same conditions, id bet money the younger clone would not only be as large or larger at harvest than the january cut, but it would be less susceptible to pest and disease.

theJointedOne said:

id bet money the younger clone would not only be as large or larger at harvest than the january cut, but it would be less susceptible to pest and disease.

Click to expand...

Im not the guessing/gambling type LOL!

Could you do a side by side comparison thread? Ive read many references to fresh clones being put out later in the season catching up (and even surpassing) plants that were put out earlier.

There is alot of opinion oriented "facts" about growing, this would be another good one to document if it hasnt been done well already, ill search again now though.

Something to remember also are the characteristics of the root system for a given strain, a clone from one strain very well may be able to surpass an older plant of the same strain if it needs mininmal rootspace to be productive. Some strains NEED rooting time/space and will need the long veg period to be productive, Its why planting different strains in the same size pots there is so much variation to growth/yield patterns. (I talk alot about this in my max efficiency growing thread, i would appreciate you additions to that discussion as well.)

I myself have transplanted Blue Dream clones from 1.5 quart pots of coco to 7 gallon pots of 50/50 blend fox farm ocean forest and happy frog soils with 30% perlite before putting outside late in the season to go right into flower, given chlorine/chloramine laden Chula Vista tap water only.

These plants got axed at around end week 3 flower because my cousins wife got paranoid one day out of the "Blue Dream" lol. Coming from the 1.5 quart pots they had fully rooted into the 7 gallons of soil they were given, holding all of it in a dense rootball in only ~3 weeks. Need to remember strain root characteristics though, Blue Dream is an explosive fast root growth variety and honestly seems to adapt and thrive in any envrionments, its a great example of hybrid trait exaggeration in many aspects.

I just remembered this thread and wanted to add i read alot into monstercropping (taking clones from plants early flower) last year and learned theres no point in keeping one specific plant alive for long periods of time, its good to refresh your mother plant intermittently imho.

Link To Thread: Continuous Monster Cropping and Plant Degradation
https://www.icmag.com/ic/showthread.php?t=224569

Posted May, 17, 2017:

Natural high said:

Excellent analysis. As someone with a biological science background and 35+ years growing experience I think I can add further to the discussion.

Epigenetic change refers to a situation when the modification of a genes expression is permanent and therefore inheritable.

In all organisms, genes are turned on and off in response to environmental change and the influence of hormones at the cellular level. A good example is when a woman becomes pregnant. Many major changes happen during the pregnancy, facilitated by hormones altering gene expression. When the pregnancy is complete, the changes in gene expression are reversed.

In cannabis, a reduction in day length (long dark period) alters gene expression via hormonal changes and this results in the flowering response. As cannabis is an annual, in nature this is usually the final expression of the plants morphology and concludes with senescence and death.

But if we expose the flowering cannabis plant to long day length we can reverse the changes in gene expression and force the plant back to the vegetative state, similar to the woman when the pregnancy is complete. The question is; is the reversion back to the vegetative state complete, or are there some genes which have remained in their modified state? If so, then this would result in a plant with a phenotypic expression which is different to its previous vegetative state, and any subsequent cuttings will also show this phenotype.

I have been cloning multiple strains for over 25 years and have regularly taken clones from plants well into flowering. I have also maintained a Jack Herer cut since the early 2000's. In my experience I have never had any phenotypic change in my cuttings despite not keeping a mother plant and always starting with new cuttings each grow cycle.

The so called monster cropping response is simply because when a plant is in flower the internode length is extremely short (within the bud) and so there is many nodes available to re-sprout when the clone reverts back to a vegetative state. Taking cuttings off this plant (once it is fully back to the vegetative state) will not carry this morphology across - the cuttings are invariably identical to the original mother prior to flowering. There has been anecdotal reports over the years of cutting lines changing over time - losing vigour, potency etc. but there has never been any concrete evidence of this happening and I certainly haven't observed it.

.

Click to expand...

Don’t do that. Hormones are powerful things not meant to be messed with. Don’t believe me...go down on a female bodybuilder and tell us how you liked it