From
motacos' "Ultimate Sativa Thread" revival at icmag, emphasis mine:
"The amount of nutes you feed your sativa is also going to effect how long it flowers to a pretty dramatic amount in some cases. This is another place people try to grow sativas like indicas. With a hybrid plant as we all know those last 3 weeks or so is when all the real weight is put on. And you don't wanna skimp on ferts at this time. If the plant runs out of N its not going to produce as big of buds as it could've. So people usually feed up until about a week or a lil longer then they quit feeding. Which is what you should do for most plants.
But sativas aren't most plants. The reason those hybrid buds get so big and resinous those last few weeks is they think winter is coming. They are secreting resin trying to catch pollen, and desperately trying to produce enough energy in the buds to take care of seeds before a frost ends their life over night. Since there are no seeds they produce bigger buds.
But alot of sativas are from places there is no real winter to speak of. Some places near the equator plants live for years. Most have no genetic background to be prepared for the concept of finishing for a frost.
What determines finishing time for tropical sativas is nutrients. When they are in the wild there is no frost that forces them to try to make seeds. But if they run out of nutes they will die and so will their seeds. So
when they start feeling nutrients running out in the ecosystem full of other nutrient thieves they know they need to put all energy into bud production for seeds and not growing more stem and leaves.
By keeping feeding your sativa N as fan leaves die during flower you are accidentally telling your plant that their ecosystem is thriving and they should compete to outgrow other canopy. Stem and leaves in other words which also extends the plants flower time dramatically. New growers often accidentally flower plants for nine months and stuff confused why new growth keeps coming out. Wondering when its going to end. This not only effects flower time but also the high. All those clear trichs aren't ready and produce anxious headache type stone mixed into your euphoric sativa.
As the plant yellows during the last month... good let it. Its natural.
As long as it has P and K it will produce nice buds that are ready to finish in unison. Without all that new growth popping out of old growth. Sativas need very little N to produce growth; trust me. Let it finish you'll be happier with PROPERLY mature sativa buds for a change in a shorter period than you would have. This is the mistake so many growers make and why their weed is anxious and takes so long to flower.
Also leads to alot of negative opinons about sats.
Flushing is real simple. just don't drown them. Its just like getting rid of a hangover. coffee or a cold shower don't do anything. only time and detoxing. Just use plain old water that last month with that sativa and you'll be fine. And thats about it for the grow.
... without question the fastest way to get off a sativa harvest."
...
more from motaco
"very few people realize this but how long sativas take to harvest is very closely linked to fertilizer regimen. during the end of mid flower leaves begin to yellow but the buds have more time to them.
growers react the same way they do with hyrbids and touch it up with a tea heavy in N. when really the plant was getting ready to finish and its part of the sativas biological clock was kicking in; the grower inadvertently told his plant that death was not coming, to keep striving to live, and the plant takes much longer to finsih. let me get an exerpt from mj growers handbook to help me illustrate how and why this happens.
"Plants growing in the wild outdoors obtain their nutrients from
the breakdown of complex organic chemicals into simpler water-
soluble forms. The roots catch the chemicals using a combination
of electrical charges and chemical manipulation. The ecosystem is
generally self-supporting. For instance, in some tropical areas most
of the nutrients are actually held by living plants. As soon as the
vegetation dies, bacteria and other microlife feast and render the
nutrients water-soluble. They are absorbed into the soil and are
almost immediately taken up by higher living plants." - ed rosenthal
now in places like colombia or thailand where there are native strains that can take as long as 6 months (in extreme cases) it is not uncommon at all for a plant growing a hill side that catches runoff to grow gigantic plants of very old age. often there will be 2 weeks of flowering growth, 2 months of flowering growth, and buds that have BEEN dead all on the same plant. and every bud age inbetween.
so its a normal reaction to biological cycles.
if it happens TOO early than go ahead and give it a lil N. but beware, sativas greatest joy in life is turning N into leafy elongated buds.
another determining factor to how long a plant grows is root space, which you will become well aware of if you grow sativas.
if sativas have an unlimited root space they will want to flower longer, grow longer nodes, and ridiculous heights.
typically you will repot sativas many more times than other plants. you want them to feel their restrictions, before they get too tall. anyone who has flowered a true sativa from seed will attest to this. it is not uncommon for a sativa flowered from seed to reach 6ft in two months. it is also advised to bend your stems and keep high winds and all other tricks to promote healthy stems. not only does this make the stems capable of handling large buds, but also any energy you can detract from vertical stem growth and put into other positive attributes will help limit space between nodes, and thus give you bigger, denser buds. when you limit the roots your limiting allowed vertical growth which at the same time is making tighter internodes. so long as you don't get rootbound your doing a good thing.
you generally wait until it gets a good rootmass, where when you remove the pot you can see healthy rootmass from the outside all the way down and then repot. grazing the roots lightly during repot promotes new root growth.
when you repot remember your trying to keep the pots on the smaller side.
once the real serious amounts of stretching are done a few weeks into flower you can give them much more rootspace for bud development.
IMHO sativas should be grown in a soil or soiless with slow release all organic mix. sativas often become quite unmanagable under aero or hydroponics and are well documented to usually prefering organics over chems."
Thank you, motaco.
In
this thread, Hempy (originator of the Hempy Bucket) addresses sativas ... more studying for me! Like our buddy quazi says, "the more you read, the better the weed." I have to say, that is exactly the reason I'm doing as well as I am with this first grow - I read A LOT.
According to Hempy, since (from what I gather) DP is a near-pure Sativa, I shoulda thrown 'em into flower much earlier. With this in mind, I'm VERY happy I decided to practice LST.
The lights are off now or I'd take a pic of the lovely buds already developing. And still no dingle-balls or nanners!
Is this to be expected or is there a lesson here for me? 
Because I do not like it. I can LST the tall ones out to the side to make a bowl shape but, just how long (tall) do sativa side branches get, anyway? Shopping list for next grow: Bushmaster.
Thanks for any and all help.
they may make them crispykiss-ass
