8 weeks flowering sativa, sudden change in behavior

[krikri]

Hi all, I've got a couple of flowering sativas indoors, and here's the situation I'm dealing with one of them:

For a couple of weeks now, the vertical growth had stopped and the plant showed maturing signs: buds were swelling, pistils were changing color, lots of trichs in the buds and bud leaves. But for the last few days the plant has suddenly resumed vertical growth - the main cola is getting taller again, as small buds grow higher and higher each day.

A little background and details:

- Soil
- CFL lights
- PH ~7 (analog PH tester)
- Temps: 60-65F day, 45-50F night
- RH: dependable, usually around 60-65 day and 70-75 at night.
- Nutrients: a mix of two commercial products, 4-10-40 & 12-48-8.
- Water: Plain tap water (PH: 7.5) left in the open for a couple of days to evaporate the chlorine.

I gave her a bit of a nute burn last week, so I flushed with success, and watered once more with plain water since.

Here are a few pics, any ideas why this is happening?

 

[jmansweed]

I'd stop with the Nitrogen in the added Nutreints. What kind of soil?

 

[Alistair]

I'm not too sure about the nitrogen, but it's something to consider.

An analog meter isn't considered to be reliable for measuring pH. It's much better to get a digital one.

The temperatures seem a bit on the low side for the daytime, and quite low for the nighttime. Perhaps, you could raise the temperature to 75-85 degrees during the day, and to about 60-70 degrees at night. I've read that a 10-15 degree difference between day and night is ideal.

Also, the rh is potentially too high. This could lead to mold.

Looking at the fluffy flowers you have, I'd say that you haven't enough light.

Stick around and others will join in and help out. Good luck to you.

 

[krikri]

Yes, I'm also worried I've been feeding more N than I should, so I was thinking of sticking with the lowest fertilizing solution I've got(4-12-40), that happens to be higher in K. I understand she needs extra P while flowering, but will this be enough?

How about K during flowering? The local shop I bought it assured me that high levels of K during flowering help with bigger and better flowers, and according to the product's information it is ideal for bigger and better flowers & fruits. I guess fruits in sinsemilla is buds, right?

Or should I just find a nutrient solution with 0 N? This one should be tricky around here, and if I order online it would take forever to deliver.

Soil is plain peat moss soil I picked up locally, BTW, if that makes a difference with this issue.

 

[pcduck]

A lot of sativas will have a second growth spurt, that has nothing to do with the amount of N

 

[BBFan]

Hello KriKri-

Long time no see. Your grow seems to be coming along nicely.

Alistairs right. You really need to get your temps up. Under 50F is just too cold for mj. And your daytime temps would be better off around 75 to 80. You'll see much better growth and development.

Your rh is quite high also. Anything you can do to bring that down to 30 or less will help your plants.

Personally I don't think it's the nitrogen that's doing it. I had something similar happen on a recent sativa grow- a late spurt of growth- the main colas look like they had ears. I was having some temp issues with mine during that grow (getting too cold at night- around mid 50's). Growth really slowed for a while before it happened. So I don't know if there's a correlation there or not.

Bottom line is the plants were fine at harvest time. I'm guessing they'll be ok.

Good luck to you and have an enjoyable holiday.

 

[legalize_freedom]

The only thing I can add...is yes, get your temps up, and the rh down.

Are you sure you are not geting any light leaking in during your dark cycle??

Sat's can have several growth spurts throughout their lives, they will seem to do nothing for a couple weeks and then go crazy.

 

[leafminer]

By the look of that third picture your plants are going into reveg.
I had the same problem at the end of my last outdoor grow. Another member pointed out that I had been using a high-nitrogen feed in the soil (pasteurised sheep manure) probably causing reveg.

 

[dirtyolsouth]

:yeahthat:

If you can, get inside your grow space during lights out sometime to make certain that you don't have some light leaks cuz like LF suggested but a big dose of nitrogen can do the same thing.

Peace!

 

[krikri]

Hello KriKri-
Long time no see. Your grow seems to be coming along nicely.

Hi BBFan,

Yes, I've been reading more than posting lately - unfortunately not enough time to do both these days, so I'd rather be silent and read as much as I can rather than talk about my grow and miss out on reading

Thanks for your support, best of wishes to you too

I was having some temp issues with mine during that grow (getting too cold at night- around mid 50's). Growth really slowed for a while before it happened. So I don't know if there's a correlation there or not.

Yes, I think there is - growth was indeed painfully slow during the past four weeks or so, and I know temps are responsible for this. Especially for sativas, since I understand they originally come from equatorial areas, so their ideal temps are high. This is not something I can fix right now though, so as long as a delay in harvesting won't kill my plants I guess I can live with it.

I'm also aware that humidity is higher than supposed to be for flowering - I'm already using a dehydrator, but RH has never fallen below 60, and I turn it off during the night because of the noise. I've been keeping a close eye for mold signs, and so far so good. Is there anything I should watch out for specifically, other than white mildew?

Sat's can have several growth spurts throughout their lives, they will seem to do nothing for a couple weeks and then go crazy.

Sounds very familiar - hope she doesn't get too crazy, I've already bent her enough, I could be running out of bending space soon....

By the look of that third picture your plants are going into reveg.I had the same problem at the end of my last outdoor grow.

Hi leafminer, I've read your thread about the reveg issue, and quite frankly this is one of the reasons that got me worried. Still not sure if I have been feeding too much N, both fertilizers are low on N, but then again she did go through a nute burn last week...

Are you sure you are not geting any light leaking in during your dark cycle??

If you can, get inside your grow space during lights out sometime to make certain that you don't have some light leaks cuz like LF suggested but a big dose of nitrogen can do the same thing.

The grow room is also used as a storage room, so I might enter during the dark hours to pick up or store something. Lights are never on for more than 2-3 minutes each time, and the plants are inside a grow cabinet in the far end of the room. TBH, lately I haven't been shutting the cabinet's door completely during the dark hours, since the fans are hooked up to the 12/12 timer which means there's no ventilation at night. I did that because I thought fresh air entering the cabinet would improve the CO2 levels. Does this qualify as a light leak issue and if so, is this enough to cause a re-veg?

Here's a picture that better shows what's going on - denser main cola bud below, smaller buds growing on top....

 

[BBFan]

Hey KriKri-

I hope you figure the problem out (if it is a problem at all). I tried to find a pic from my last sativa grow but couldn't find one that showed the additional growth.

From the pic you just posted, it looks similar to what I experienced.

Nice juicy cola you got going. All the best to you and yours.

 

[Locked]

45-50f at night is no good...that's one problem right there...

 

[leafminer]

Yeah that is very similar to what I saw. You will probably get airy buds too; the whole cola will start to grow out.
If I am right there are not too many options:
1. Harvest - but depends on the trichs.
2. Lift the plant out of the pot, wash away as much soil as possible from the roots, repot in a slurry of new media and gradually add more solids as the mass firms up. Pretty drastic.
3. Reduce the light hours to 10/14? In my case the grow was outdoor so I couldn't try that.

 

[krikri]

You will probably get airy buds too; the whole cola will start to grow out.

Fortunately no such progress yet, the rest of the cola is still swelling. And some of the buds on the other colas were airy before that, but most are still O.K.

1. Harvest - but depends on the trichs.

I'd love to do that, it would save me some space and light for the other plants, but it would be a shame for the main cola...not enough ambers yet, looking for at least 30%. And most of the pistils haven't even changed color yet, so I guess I'll wait for another week or two, and depending on how it goes I'll consider chopping down the main cola and leave the others a little more.

 

[pcduck]

If nothing wrong let it go..My Durban Poison(sativa) does this growth spurt every time. The buds will fill in, then you may even get another growth spurt, ime at least with the Durban Poison the plant matures before this second growth spurt fills in completely. I also do not run a high N in flower and it still does this. using 600 watt hps. Also in ime most sat's are not as compact and super hard nugs like indica's. In other words more airy. :aok:

 

[legalize_freedom]

I would agree with pcduck...don't expect dense, rock hard, nugs from a sativa dominant plant. And they don't look anywhere near done yet, I'd let them go until they are done, or you have done all this work for nothing.

 

[dirtyolsouth]

The grow room is also used as a storage room, so I might enter during the dark hours to pick up or store something. Lights are never on for more than 2-3 minutes each time, and the plants are inside a grow cabinet in the far end of the room. TBH, lately I haven't been shutting the cabinet's door completely during the dark hours, since the fans are hooked up to the 12/12 timer which means there's no ventilation at night. I did that because I thought fresh air entering the cabinet would improve the CO2 levels. Does this qualify as a light leak issue and if so, is this enough to cause a re-veg?

Here's a picture that better shows what's going on - denser main cola bud below, smaller buds growing on top....

Hi,

I just made it back to your post and read the info... I really think this is more than likely enuf to cause photoperiod confusion and re-vegging. Your nutes are relatively low in N compared with PK so I dont think it was N related. I'd really try to get a handle on keeping the dark period uninterrupted in your grow room. At night you don't need any CO2 as the plants only use it during the 'day' as a component for photosynthesis so your best option is probably to close your cab during the darkness period. If this is an area that you need to have access to during their 'lights out' i suggest you look into getting a green colored dim light bulb or a green filter you can put over a flashlight to help you find things when it's dark.

It looks like you have a lot of white pistils and I dont see any red/brown dying pistils yet so you have a ways to go yet. You more than likely have another month or so before she's going to finish up but light leaks can cause confusion imo that could prevent or delay a proper finish.

Happy Growing!

 

[GeezerBudd]

I'd think that was too much phosporus. 16-58-48?
Take care of your light leaks and hook up your fan to run at all times.
I would also think using peat moss only could have something to do with it.
Bring fresh air in with no light leaks.
What commercial products are you using?

Gb

 

[krikri]

At night you don't need any CO2 as the plants only use it during the 'day' as a component for photosynthesis so your best option is probably to close your cab during the darkness period.

Thanks for the tip, I didn't know that so I've been doing it since I read your post. It helps with the temperature, too, and I've also put a small portable dehydrator in there to help with the humidity as well.

I'd think that was too much phosporus. 16-58-48?

Not sure if the phosphorus was too much, but I definitely fed them a bit more at some point, because this plant got a nute burn last week, and the others showed early signs of a nute burn as well. Since then, I've slowed down on the nutes on all of them, now feeding them half strength once in every second watering, as I did in the beginning of flowering.

It looks like you have a lot of white pistils and I dont see any red/brown dying pistils yet so you have a ways to go yet. You more than likely have another month or so before she's going to finish up

And they don't look anywhere near done yet,

You can't really tell from these pictures, but there are red/dying pistils scattered around, especially on the lower buds. The pictures I'm attaching show this better.

I'm thinking that I would like all pistils to die (or at least most of them) before I start checking on the trichs. The trichs wouldn't become amber before pistils die, right? Or do both pistils and trichs change color at the same time?

 

[pcduck]

I'm thinking that I would like all pistils to die (or at least most of them) before I start checking on the trichs. The trichs wouldn't become amber before pistils die, right? Or do both pistils and trichs change color at the same time?

The pistils can die at anytime, does not mean plant is ready to harvest.

Oh and MariP sort of frowns on posting of outside links. Most posters change the tt to XX to avoid this posting of outside links.