New Grower The life cycle of auto flowering cannabis.

Another common question I see is when to switch autos from veg to bloom. Many people are under the impression that as soon as they see the first flowers it's time to switch. Perhaps a little explanation of the life cycle of autos will help to clarify this.

Weeks 1 - 3. Once you've started your seeds and they break the surface of the soil, they are in their seedling stage. The first set of leaves to appear will usually single fingered, followed by a second set that may still be single fingered or perhaps 3 fingered. Once that second set appears growth will start to accelerate as the new leaves provide more photosynthesis. This process will continue, more new leaves, faster growth. Depending on the type of soil in use, mild vegetative nutes can be introduced at week 2. By week 3 most plants will start to show their sex. Males will start to produce pollen sacks and females will display pistols.

Weeks 4 - 6. The plants are now entering a pre flowering stage. During this time the plants should exhibit explosive growth, often as much as a new set of nodes and 1" vertical growth a day. This is the time when they will gain most of their vertical height. Many people make the mistake of switching from vegetative to flowering nutrients at this point, assuming that since they see flowers it must be the proper time. This is incorrect. If the switch to flowering nutes is made at this time the vertical growth will stop and the plant will put it's energy into producing buds. If you need to keep your plants small, or want them to finish earlier, they by all means switch nutes at this point. But if you want to get the most out of your plants continue feeding vegetative nutes until you see the vertical growth slow and stop. Depending on the strain that will usually be sometime during week 5 or 6.

Weeks 7 - 9. By now vertical growth has stopped and the switch to flowering nutrients has been made. The buds will start to fill out and put on weight, becoming hard and tight. Pistols will start to change from white to brown, orange, red, etc. By now the plants will also have developed a strong smell. Toward the end of this phase the large primary and smaller secondary fan leaves will begin to turn yellow. This is an indication that the plant is moving toward the end of it's life.

Weeks 10 - 11. At this time flowering nutes should be discontinued and only plain pHed water fed to flush the remaining nutrients from the soil and improve the taste. Yellowing of the fan leaves will continue as the plant draws the stored energy from them. Eventually they will die and fall off. By the time that the smaller leaves that come from out of the buds will also start to turn yellow. Then it's time to harvest.

I know that many of you are thinking that the seed bank said the plants will finish in 8-9 weeks, so why are you saying they take 10-11? The claims made by the seed banks are somewhat deceptive. If you switch to flowering nutes at week 3 or 4 the plants can finish in the times the seed banks say but they will remain small and not reach their full potential yield. Years of growing by myself and others has shown that autos do best if you follow this time line.

Of course, there will always be variations depending on the strain, the environment, nutrients, etc. This information is meant to only serve as a general guideline.

For more detailed information on when to harvest your plants, please see: https://www.autoflower.org/f44/when-harvest-autos-your-leaves-will-tell-you-4889.html.

NOTE: This is an informational thread. Do not post specific questions about your grow here. Please start a new thread in the appropriate forum.
 
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Sorry, my old 1 M pixel camera won't show much detail. Just wondering as a general rule about harvesting autos outdoors. New to autos & just trying to get a general feel for them.
Kudos to Muddy for original post, I would have had a lot of questions when my indoors autos' leaves started turning brown at the end of life cycle :lol:.
 
I hate the term flush at the end as it's often confused with flushing for a problem where you give lots of water. For the last two weeks just give plain pHed water, enough to get 10% run off like you normally would, when ever the pots are dry.

Yo Muddy, when you say 2 week flush, do you mean you flush your plants over the 2 week period (for a 10l pot give the plant 20 liter spread out over 2 weeks), or do you mean you flush it once (like feeding the plant 20 liter water in one time for a 10l pot), 2 weeks before harvest and then only feed plain water when the soil gets dry? (in the case you use soil)
 
They will withstand light frost, but not a heavy one. But once the soil temps start to drop and the roots get cold, they really slow down and will pretty much stop growing.

How do autos fare with the cold? The rudiralis genes shoud have a hardyness for cold built in woud'nt they?I don't mean the roots but the top part.
 
Once soil temperatures drop it inhibits the plants ability to uptake P. A lack of P turns the stems red/purple and eventually the leaves will turn purple and growth will slow and stop. I've only done one late grow where I've seen this and I continued to wait for the leaves to yellow, but they never did. After 16 weeks I gave up and harvested the plants. I could have picked them after 12 weeks with about the same results.

Question on auto harvesting outdoors. Do you still try to wait for all the fan leaves to yellow before harvesting?
I've got a test NLxBB auto going outdoors in the NE (planted ~ 10/9) & the leaves are turning purple, not sure if that's an indicator or just the strain. Plant got put in the ground late & was somewhat mistreated through ignorance (mine) when it was small. It's only 9/10" but has plenty of leaves & small buds.
Thanks.
 
Thanks Muddy, hasn't been that cold yet, 50-60 night, 65-75 day & a couple of lower leaves are yellowing. It's a test/learning grow, I'll just let it go until temps start to really cool down or most leaves yellow..
 
I hate the term flush at the end as it's often confused with flushing for a problem where you give lots of water. For the last two weeks just give plain pHed water, enough to get 10% run off like you normally would, when ever the pots are dry.
Aww shoot, read this too late. I just 'flushed' them, as in give them lots of water at once, which was advised on a different website.. Is this really bad and should I still feed with a low amount of nutes which I decrease in the following couple of days? Or is it not really a big problem?
 
Shouldn't be a problem. Just give them water when they are dry from here on in. At this point in the grow the plant is mostly drawing from the fan leave for nutrients anyway.

Aww shoot, read this too late. I just 'flushed' them, as in give them lots of water at once, which was advised on a different website.. Is this really bad and should I still feed with a low amount of nutes which I decrease in the following couple of days? Or is it not really a big problem?
 
Shouldn't be a problem. Just give them water when they are dry from here on in. At this point in the grow the plant is mostly drawing from the fan leave for nutrients anyway.
Ah, cool. Yeah true, so I assumed it was OK to stop feeding them, but in hindsight I might have simply stopped feeding them nutes, but feed them plain PHd water, instead of flushing all at once.
 
Listen to your girls they will show you what is wrong...........:bong:
 

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