WHAT IS AN AUTO?
As we all know, cannabis is a photo-period plant: ie it’s flowering hormones are triggered by changes in the light/dark cycle. Thus you can stimulate a 2 week old cutting to begin flowering by giving it 12 hours of darkness, yet a 4 month old plant grown outside will remain in vegetative growth until mid-summer has passed.
Autoflowers are a different breed altogether (quite literally!) and will flower according to the age of the plant rather than the light/dark cycle. This development has been obtained by crossing a ruderelis strain with a standard photo period plant. Unfortunately ruderelis is fairly weak in the desired thc levels so the first autoflower strain developers had to stabilise two dominant traits: the high thc level provided by the photo-period parent and the all important auto gene from the ruderelis strain. As you can expect, early attempts were generally disappointing, and as little as four years ago autos were viewed as unreliable with poor yields and low thc levels. Most sensible growers put them down as gimmicks for newbies.
Today if you see an autoflower seed for sale you can be (reasonably) assured that its THC content will be as advertised, and its auto gene stabilised.
HOW LONG DO AUTOS TAKE?
Now this is the big question. Most breeders claim 7-9 weeks, with some even boasting seed to harvest in less. It would be fantastic if one could get 50g per plant after just 39 days, but lets face it, its totally unrealistic. A plant doesn’t grow any faster for having an auto gene, and the dwarf autos that will harvest in ultra quick times are just that: dwarfs and thus yield is limited by size.
Of the 15 or so different commercial strains I have tried, not one of any consequence finished in less than eleven weeks – and the best ones can take anything between 3 and 5 months. If you think about it, this is not surprising: most standard autos start showing their sex at around 21 -28 days (super autos not included) – if you add on a flowering time of 8 weeks (average flowering time for a indica) then you would be looking at 11 – 12 weeks.
IMPORTANCE OF A GOOD START
I think this section is the do or die between having a great auto crop or a disaster. Autoflowers have such a short vegetative growth period and the final plant is rarely very big. Get it wrong and you’ll end up with a lollipop stick of bud. That’s why I think that whilst autos fulfil a gap in the outdoor growers repertoire (after all its damnedably difficult to control the light/dark cycle of the sun), if you can its best to start them off indoors under lights. You just maximise the level of control that way.
CAN I TAKE CUTTINGS FROM AN AUTO?
“Once you pop ’em you can’t stop ’em”
Effectively this means that whilst the answer is “yes”, the autos have a genetically limited life: from the moment the cannabis seed germinates it will progress through its short vegetative stage and speed onto flowering. As the “mother” plant won’t be big enough to take a clone until she is around 5 weeks old, once you have added a week whilst the clone roots, the clone thinks of itself as 6 weeks old and upward vegetative growth will have finished. Despite being tiny, the cutting will finish flowering at the same time as the mother more or less – here’s one I tried for a laugh:
guide to autoflowers
FEEDING REGIMES FOR AUTOS
Start off with a little veg feed at around week 2 and slowly increase the amount of feed as the plant develops up to (depending on the auto) around week 6 or even 7. Wait to switch to flower food until after the cannabis plant has noticeably stopped its upward growth, even though she may have been flowering for a week or so beforehand.
LIGHTING REGIMES FOR AUTOS
You can grow autos on 24/0 but I think its good to let them have a little rest time and electric consumption is also a issue. I grow mine for the first two weeks under a 120 watt draw Fero LED for the first couple of weeks and I tend to keep that on for 21/3 with the LED grow light around 70 -80 cm away from the seedlings. When then they are potted on to the 13 cm sexing pots and put under my larger LEDs I then change the lighting schedule to 18/6 where it will remain until I crop.
CAN I MERISDIAN PRUNE (TOP OUT) AUTOS?
Yes you can but it needs to be in the very early stages as it holds the plant back in that critical time. I’ve experimented over several crops with this and my advice would be that you are better off not pruning autoflowering marijuana as in most cases the plant will end up giving less weight. That said, you can break the apical dominance and encourage vigorous side branching by “knuckling” if you are using a longer term variety such as the “Cream Caramel” (yes Sweet Seeds, I know you say this is an 8-weeker, but every one I’ve grown has gone to 12 weeks plus).
HOW MUCH WEIGHT CAN I GET FROM AN AUTO?
Lets assume your environmentals are all good, with light at around 400watts a m2, temps at around 23ºc, humidity 55% for flowering and you are replenishing your air every couple of minutes whilst maintaining a good nutrient regime and getting plenty of O2 to the roots etc etc (who ever said growing great smoke was easy?)
The simple answer is : it depends on how long the plants are going to take. The 3-monthly varieties such as MI5 (Shortstuff) average around 40g a plant (dried weight) under my fero led lights at 10 per m2 and the longer super varieties such as Chase (15 weeks) 150g -500g a plant outdoors.
Here is my post on autoflowers hope this well help