Growing in Greenhouse in Early Spring - Natural Light

Ok, first a few assumptions so that I may pose this question clearly.

1. Location is Eastern US, 38-40 latitude. Goal is to grow in greenhouse environment under natural light in early spring, Mar-May.
2. Mother plant is (to be) healthy and of a 45-day "trigger happy" sat-ind cross.
3. Mother is (to be) growing indoors under a 18-hour per day HID light regimen and is in a fully vegetative state at the time cuts are taken.
4. Cuts are (to be) taken on February 1, 2010. Cuts are rooted under flouresc lights then moved to a HID for modest grow-out.
5. At this point it is (to be) Mar 10, 2010, 5-6 six weeks later, and it's time to bring them out into the greenhouse (natural day-light and length) for blooming.
6. Sun is on the ascendancy and days are barely 10-12 hour total daylight, still quite short. It is 90 days until the solstice where there will be 16 hours of daylight.

Ok, here's the question as best as I can phrase it:
Without using supplemental lighting in the greenhouse to "extend" the day-length, can the young plants be counted on to go into and STAY INTO bloom, given the short days and the gradually increasing day-length of late Mar and onward into late May and June.
This question gets to the heart of whether cannabis is more sensitive to day-length (mums, pointsettias) or crop-time length (like corn). My understanding is limited. I think most of us assume it's day-length that triggers cannabis; hence the general method of moving from 18-24-hours down to 12-hours at bloom time. But can a plant that was fully vegetative under a STRONG 18-hour cycle as a young, rooting cutting be counted on to GO BLOOM and stay there in the early spring under NATURAL LIGHT ONLY as the day-length gradually increases to it's max on June 22nd?

The reason for getting this question answered clearly and accurately in advance is obvious; if this gorwing can't be done without supplemental lighting and the necessary electricity protocol and photo-period manipulation curtains (standard in the green house industry) then plans for these things must be made well in advance or greenhouse growing scrapped altogether.

Any EXPERIENCED advice and input would be GREATLY appreciated.
Peace.

Yo Ho kidsnmotion,

A true autoflower strain should flower on any light schedule including 24/7. Because it flowers when mature and not photosensitive. This says it all...

smoke in peace
KingKahuuna

so...... what do you mean by "true auto flower strain" and who has these?

Autoflower strains are strains that have been mixed with ruderalis and will flower independent of the light cycle. Unadulterated cannabis depends on the light cycle to flower with 12/12 being stated as the usual trigger point though this can vary widely depending on the strain you are growing. You would need to do your own experimenting with a single plant to figure out ITS needs to force flowering but 12/12 is a blanket schedule that pretty much gaurantees all plants will flower.

Autoflowers can be found at most seed banks. They will not work for your plan though if you plan on growing from clone as they start to flower before you can take clones from them. IMHO they are junk and I wouldn't touch them with 10 foot pole. That being said plenty of people like them and they do fill a niche but any serious grower will usually keep a stable of mothers to lock down characteristics they are looking for in a plant. Growing from seed when growing for production is a major pita.

Auto flowering flower at age no matter what the light is.

At week 3 they will start flowering, it doesn't matter if its dark winter of hot summer.

Auto's are an outside growers dream, (more light bigger harvests, less light lower harvests)

Biweekly harvest are achievable from march onwards.

Some people can only grow outside, so if there is a plant that will give on average an ounce per plant at any time of the year while waiting for the big girls to finish, who would decline it?

All smoke is smoke.

eace:

Tater,
Ok, If I wish to stick with the cross I already have I think I'm hearing you say that I'll have to use curtains as the increasing day-length will nudge them out of bloom and back into veg. Curtains are ok as it's nothing more than a little capital expense and the daily drudge of 12-12 open-close. Been there before.
Supplemental light is a considerable problem however as electricity is smart-metered and closely watched in many areas. Basically, supp light is a no-go as far as I'm concerned.
So, my remaining question has more to do with yield reduction w/o supp light. Do you think that lat 38-40 Mar 15-May 15 will work? Or do I need to move it forward to April 10-June 1.
Greateful for your input. And btw, what did you mean by IMHO and ITS? And "pita"?

ummm.. i cant say much about it. But i m excited to follow this.
I m trying to 90% natural light also.
Thanks for the info.