Hello my plants are 6 weeks into flower and the fan leaves up top especially aren’t looking to good. My tent temps are between 68-72 F. Humidity upper 50s low 60s. I’m growing in fox farm ocean forest soil and feeding with fox farm tiger bloom and big bloom. Thanks for any help
Fan leaves turning yellow/brown during flower
- Thread starter jakamini
- Start date
singlecoiled
Well-Known Member
I'm afraid I can't be too much help as I'm also having the same problems at around week 6 flower with all of my grows.
If it were me, I'd check the soil PH or at least test the run off to see if your PH is low. All of my tests at around week 5-6 of flower (in fox farm soil) have shown very acidic soil..PH at 5.0 or lower. It might be time to flush the soil to remove salt buildup. If you water at a neutral PH of 7 or so and the runoff is testing in at 5 or lower, something ain't right !
The second thIng I'd recommend is reading up on the problems using "bloom " nutrients. In fact, many experts hardly touch them and continue giving grow nutrients the entire grow. I'd go real easy on the tiger bloom. Your leaves may be yellowing due to lockout or simply a lack of nitrogen. (which might be missing if your feedzing bloom nutrients only.)
And last but not least, yellowing can occur naturally towards the end of your grow. It can be hard to tell if you have a problem or if the plant is just running its course. I wouldn't sweat a small amount of yellowing late flower, but watch for all hell breaking loose,.
If it were me, I'd check the soil PH or at least test the run off to see if your PH is low. All of my tests at around week 5-6 of flower (in fox farm soil) have shown very acidic soil..PH at 5.0 or lower. It might be time to flush the soil to remove salt buildup. If you water at a neutral PH of 7 or so and the runoff is testing in at 5 or lower, something ain't right !
The second thIng I'd recommend is reading up on the problems using "bloom " nutrients. In fact, many experts hardly touch them and continue giving grow nutrients the entire grow. I'd go real easy on the tiger bloom. Your leaves may be yellowing due to lockout or simply a lack of nitrogen. (which might be missing if your feedzing bloom nutrients only.)
And last but not least, yellowing can occur naturally towards the end of your grow. It can be hard to tell if you have a problem or if the plant is just running its course. I wouldn't sweat a small amount of yellowing late flower, but watch for all hell breaking loose,.
Last edited:
Treesomewanted77
Well-Known Member
I’m no soil expert by any means but those temps seem pretty low especially if you’re using LED lights they should be more like low 80’s on and maybe 75 off. Also I would solely go by runoff ph it doesn’t really tell ya much. What you can do is soil test and see what ya got going on.
As the above post says don’t use bloom nutrients is false also the yellowing at end of cycle is also false unless you let them run out of food. If the plants are fed right they will stay nice and green right to the chop.
Don’t flush the soil unless you absolutely have to because you will wash all the food and microbes out of it.
We need to know how much of the nutrients you’re feeding and what your watering practices are?
I would just give them straight water for a couple times when they need it and don’t ph your water soils don’t need ph’d water unless your water is really whacked but most water is fine
As the above post says don’t use bloom nutrients is false also the yellowing at end of cycle is also false unless you let them run out of food. If the plants are fed right they will stay nice and green right to the chop.
Don’t flush the soil unless you absolutely have to because you will wash all the food and microbes out of it.
We need to know how much of the nutrients you’re feeding and what your watering practices are?
I would just give them straight water for a couple times when they need it and don’t ph your water soils don’t need ph’d water unless your water is really whacked but most water is fine
Killaki
Well-Known Member
How close is your light? Some of the upper leaves look like they are taco'd so could be light stress if you temps are in check like you say.
The dark green, waxy leaves look like possible candidates for Nitrogen toxicity which can cause clawing and nutrient uptake issues, resulting in yellowing leaves, rust spots, ect.
Ps. Your plants will like it better if the fan is blowing over the canopy and causing the plant to wiggle just a little. Being blasted directly by the fan can stress it out.
singlecoiled
Well-Known Member
I've been growing in fox farm soil for 3 grows now and following nutrient feed charts (fox farm trio as an example) wound up with salt buildup and low PH every grow. I agree that you shouldn't flush unless you have to, but in this case it's needed. The salts will build up and a flush will help get you back to health. (Especially if you aren watering to runoff) in fact the fox farm feed chart specifically lists flushing the soil 2-3 times during the grow. (Or as needed)
As far as bloom nutrients go, listen to the president of dynagrow talk about the fact that the only reason they created bloom nutrients is because people think they need them. His opinion is that that only grow nutrients are needed and that over use of bloom nutrients causes more harm than good. He sells bloom because the market wants them, not because they are needed and he advises against using them. I think this says a lot.
Also, I've noticed that a lot of leaves grow after flowering has started, lack of nitrogen at this point can cause yellowing of leaves, Which is why I will be continuing to use grow nutrients into flower. You have to be careful with nutrient feed charts, they can and will get you into trouble.
Last edited:
I will measure when I get home and raise the fan thanks. I have a lux meter and will measure what the top of the plant is getting
Thanks for that info. Should I order a flush product like what fox farm makes or do you recommend a certain solution?
singlecoiled
Well-Known Member
Just plain water, your just flushing. You want to use twice as much water as soil. ( I used around 8 gallons of water for 5 gallons of soil). PH the water before using it and PH the runnoff as well. You might be surprised how much lower the PH is in the runnoff. I wouldnt bother with flush agents..
Last thing, In my grow setup, Fox Farm soil hates to get overly soaked. The poster above that advised against flushing isn't wrong, I hate doing it and it can cause its own problems if the soil cant dry in time. BUT, if you have salt buildup and or lockout, you really dont have much choice.
Since you are in mid flower, you should be fine. Your plants should be drinking enough to get the water out of the soil quickly. Notice how many times Fox Farm recommends flushing, I'd say once per grow is enough if you have problems. Also, go easy on the nutrients ! Most people use half or less if the recommended feed schedule on this chart. Hey, if your plant can handle full nutrients, great, but my experience following the grow chart caused problems. (I use half or less of what they recommend now-- especially bloom nutrients !)
Last edited:
singlecoiled
Well-Known Member
Northern Lights Fox Farm Soil, Fox Farm Trio Nutrients full doseage.
Week 5
Week 6 (needed flush, salt build up--Soil PH under 5)--- using fox farm Nutrients Big Bloom, Grow Big, and Tiger Bloom at Fox Farm recommended doses. The flush got me to harvest, almost 3 zips of great bud...
I've now swapped to Dyna grow at 1/2 doses, but have nothing bad to say about the Fox Farm nutrients. I was using too much, user error.
After Flush Side view-- still a bit rough, but the flush saved her and got me to harvest.
Week 5
Week 6 (needed flush, salt build up--Soil PH under 5)--- using fox farm Nutrients Big Bloom, Grow Big, and Tiger Bloom at Fox Farm recommended doses. The flush got me to harvest, almost 3 zips of great bud...
I've now swapped to Dyna grow at 1/2 doses, but have nothing bad to say about the Fox Farm nutrients. I was using too much, user error.
After Flush Side view-- still a bit rough, but the flush saved her and got me to harvest.
Ok I flushed with 6 gallons of water. My tap water is a ph of 7.4 and the runoff was 6.8. I’m going to let them drain into the self watering base and let the soil dry out a little. Should I wait a week before feeding with half the recommended dose?
Light is 17” from top of plant and is measuring 47,000 lux.
hotrodharley
Well-Known Member
Too much the fertilizer. Instead of using nutes in OF suggest top dressing with more OF. And just plain water.
Very nice thanks for your help
Thanks I’m out of ocean forest soil I was going to feed 1/4 to 1/2 dosage of the fox farm fertilizer. Or would you suggest ordering more soil.
BongerChonger
Well-Known Member
It's likely holding too much water and not draining properly then. Meaning, salt build-up is a high chance. It's likely an aeration problem. Then you have those cold temps making any current issue worse off.
Overwatering and overfeeding is so common in newer growers and it's most often caused by inadequate aeration at the rootzone.
Newer growers have to fluff their potting mixes out with perlite. It is so much more forgiving, and allows for a lot more user error before things take a really bad turn.
Are you amending your potting mix with some perlite? If no, I promise you'll have a much easier time if you do.
hotrodharley
Well-Known Member
If you plan on using OF again I’d just pop for a new bag myself.
BongerChonger
Well-Known Member
Sorry jakamini, my above post was mostly posted toward yourself. Got you two mixed up, cheers. GL.