Plants turning yellow 5 weeks into flower?

icky

icky

New Member
I know its normal for some yellowing well into flower but it's getting out of hand now. The Flowers were growing well but now they seem to have slowed to a crawl. They are not as thirsty as they were either. Even some of the new growth has signs of a little yellowing. I'm so close, now I'm worried.


What Strain is it? Unknown from bag
Is it Indica, Sativa or Hybrid? What percentages? looks sativa
How Many Plants? 5
Is it in Vegetative or Flowering Stage? flower
If in Vegetative Stage... How Long? vegged for 2 months
If in Flowering Stage... How Long? 5 weeks
Indoor or Outdoor? indoor
Soil or Hydro? soil
If Soil... What is in your Mix? MG 6 month/perlite.
If Soil... What Size Pot? 3.5 gal
Size (Wattage) of Light? How Many? 1 400w HPS
Is it Air Cooled? no
Temperature of Room/Cabinet? 60-80 (temps getting low overnight) heater cant keep up.
RH of Room/Cabinet? 50-60%
PH of Medium? 6.8 according to my shitty stick in the dirt probe.
Any Pests? have seen a few nats. not an epidemic.
How Often are you Watering? every 2 days, full watering.
Type and Strength of Fertilizers used? first time ever fertilized used 1/4 strength jacks classic bloom booster 10-30-20, week 1 of flower. and second dose 1/2 strength in week 3.
Size or Square Footage of Room? 12x15


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I have to wonder 2 things! temps getting too low at night and I also used water from my tap with a water softener/ salt tank system, Is the plant salted up and locked out? How to fix this?
 
I just had this problem but in veg. My probelm was not enough nutes. Maybe a nitro def in this case? I use tap water too , so i let it sit out for 24 hours in a bucket. Then i airate the water for a couple hours, before adding nutes. Not sure as to the temp being the cause, but i wouldnt be happy with my ladies getting down to 60f for any amount of time.
 
It seems the more I read the more I think the low temps are locking out the nitrogen and since a mid to late flower nitrogen deficiency is normal, the problem is compounded.
I turned the heater up, I don't know if I should feed it nitrogen or not. It likely has nitogen there just can't absorb it. I just want the dang buds to start growing again!
 
Use a Nutrient that is high in Nitrogen. A Bloom booster is high in phosphorous and potassium but low in nitrogen. Are you pots drying out normally ? If they stay moist longer then usual you may have a nute lockout. You don't need to supply as much nitrogen during flower as veg, but you still need a decent steady amount. Especially if those are sativa's, since the flowering time is longer it will need a steady amount of nutes to reach full potential. You want to give nutes every other or every 3rd watering.
 
They are not as thirsty as before. growth has stopped. I think it was the room temp. The MG soil seemed to work really well for 2 months of veg. and into 1 month flower, plants grew like crazy. but the temps have been dropping and I realized when the 400W hps goes out the heater wasn't keeping up. I never go in there after lights out so "I think" the cold has been locking out N. Someone please correct me if I'm wrong. I turned the heater way up and I hope in a week or so they start growing again. I added a 1/4 dose of 20-20-20. to one plant and totally flushed her twin sister. 6 gal. just to see if one does better than the other. Hope I'm on to something here.
 
Well rule of the thumb is house temperatures rarely drop blow 17c / 62f even in the colder months but can happen in the older style of house/drafts etc as far as i'm aware i never seen my own house temperature drop blow 16c / 60f - this is all based upon the fact the heating is turned off & temperatures stated are an average ambient.

Temperatures dropping below 15c / 59f can induce plant shock.

Remember heat/warm air rise's meaning upstairs will have a higher ambient temperature by a degree or 2, than a grow room down stairs.

Some other stuff worth a read...

Nitrogen - Plants need lots of N during vegging, but it's easy to overdo it. Added too much? Flush the soil with plain water. Soluble nitrogen (especially nitrate) is the form that's the most quickly available to the roots, while insoluble N (like urea) first needs to be broken down by microbes in the soil before the roots can absorb it. Avoid excessive ammonium nitrogen, which can interfere with other nutrients. Too much N delays flowering. Plants should be allowed to become N-deficient late in flowering for best flavor.

Magnesium - Mg-deficiency is pretty common since marijuana uses lots of it and many fertilizers don't have enough of it. Mg-deficiency is easily fixed with ¼ teaspoon/gallon of Epsom salts (first powdered and dissolved in some hot water) or foliar feed at ½ teaspoon/quart. When mixing up soil, use 2 teaspoon dolomite lime per gallon of soil for Mg. Mg can get locked-up by too much Ca, Cl or ammonium nitrogen. Don't overdo Mg or you'll lock up other nutrients.

Potassium - Too much sodium (Na) displaces K, causing a K deficiency. Sources of high salinity are: baking soda (sodium bicarbonate "pH-up"), too much manure, and the use of water-softening filters (which should not be used). If the problem is Na, flush the soil. K can get locked up from too much Ca or ammonium nitrogen, and possibly cold weather.

Phosphorous - Some deficiency during flowering is normal, but too much shouldn't be tolerated. Red petioles and stems are a normal, genetic characteristic for many varieties, plus it can also be a co-symptom of N, K, and Mg-deficiencies, so red stems are not a foolproof sign of P-deficiency. Too much P can lead to iron deficiency.

Iron - Fe is unavailable to plants when the pH of the water or soil is too high. If deficient, lower the pH to about 6.5 (for rockwool, about 5.7), and check that you're not adding too much P, which can lock up Fe. Use iron that's chelated for maximum availability. Read your fertilizer's ingredients - chelated iron might read something like "iron EDTA". To much Fe without adding enough P can cause a P-deficiency.
 
It is definitely a lockout issue. Also the salt in the water from the softener is a problem. You may want to get a water filter there are a couple out there that work well. I personally use one called a tall boy it takes the chlorine and other hard minerals out of your water using a duel filter. Air temp isn't the issue this is all about your water and nute lockout.

:smokin:
 
The room is in the attic, thats why it gets cold. I am on a well so no chlorine. I also have a top of the line water filter system w/blacklight. I just don't know how the softener works and if it actually adds too much Na to the water. I flushed one plant a few days ago but it still has damp soil and no new growth. SO, "sigh". still not sure if its salt locked or temp shocked. Def. has a N def. but which issue is causing it and how long will it take to see improvement in the new growth even if I fix it? I got the temps up to 65 F overnight which was pretty good for what it was outside. 75-80 all day with the hps lamp on it. I was thinking I should foliar feed them as an attempt to give them what the roots won't until I figure it out. I shouldn't have a mold problem, humidity is too low for it. So if its salt I need to flush right? how much tho? 3 1/2 gal pot. The one flush I did was 6 gal.
 
That looks like a classic case of nitrogen lock out. What is the ph of your runoff? You might want to check that as it may have dropped so low that the plant can't absorb the nitrogen you are giving it.
Plants still need some n in flower, check the label of your nutes.
 
I can't believe the softener would be hooked up to the kitchen tap, where I assume your filter is. Softeners are for making soap lather up, not for drinking. The ONLY filter that will remove the salt is a Reverse Osmosis.
 
OG13 said:
I can't believe the softener would be hooked up to the kitchen tap, where I assume your filter is. Softeners are for making soap lather up, not for drinking. The ONLY filter that will remove the salt is a Reverse Osmosis.
Click to expand...

The softener/filter system and uv lamp are all in the basement right after the water tank. the tap has a britta on it. The water is excellent drinking water. All I'm saying is I don't know if the water is good for plants. Na speaking. I dump 80 lb bags of salt pellets into the hopper once in a while. the water does not taste like salt so its being removed at least to a point. why am I explaining this? I don't ever remember saying it was hooked to anything or that I installed it to help the drinking quality. I appreciate the posts that are actually trying to help out. As soon as they dry up a little, I will flush the shit out of them. room temp is good now. :peace:
 
The ph of your water will have an effect for sure. But late in the game, that yellowing could your friend. The flush will reset and help
 
Busy morning. Flushed all 5 plants. amount=1 1/2 the container size Distilled water. ph of the water was 6.5. first sign of runoff I tested ph. 2 plants were really good at 6.6-6.8. Other 3 were a little low- 6.0-6.2 ish. added a small amount of horticultural lime to the last gal. of water with a 1/4 dose of 20-20-20. ph of the nuet water was 7.3. final drippage on all 5 plants was 6.6-6.8 ph. Noticed alot of little nats when I was flushing. about a dozen. so after the room was all back to normal I sprayed the lower container area with a very light plant safe insecticide. Temp is 80 deg. right now, was 62 when I went up at lights on. still cold over night. added another small heater to come on for 15 min. every hour to help but not run all the time. The white pistils are starting to turn orange. the Tiny green new growth out of the buds is covered in trichs. they look really nice. I have done all I can do for these bitches. Now its up to them to start popping again. The way they look right now I feel pretty good about it finishing with a decent yield.
 
Been a few days now since the flush. plant shows signs of leaf tip curl. Probably due to the foliar feed I gave them a day before the flush. Other than that they look to be growing again. Definately deep green new growth coming out of the buds again. I have have a new small problem now. The grow room is 80 deg. Outside the room its about 40. Condensation is actually collecting on the plastic. RH still pretty low. 50-55. I can deal with that as long as the girls are happy again. I took a few pics tonight at lights out. hps light and my camera don't get along very well.
This is a few nice lower buds.
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and a few tops
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trichs are still clear!
 
It is hard to treat plants just based on pictures, but it looks like magnesium issues. Magnesium has a hard time uptaking when the plant is cold. This is true of most all plant species.

Magnesium issues results in the purple on the lead steams. In most all cases, what fixes this issue for me is after I flush, which you already did, I feed with 1tsp per gallon Epsom salts.

It will take 4-7 days to see the difference the flush and Epsom salts make. Epsom Salt also helps the roots uptake other nutrients again.
 
My plants are yellowing too. We balance PH every watering (in the 6.5 area for use) and don't water until the top 2inches are dry. We used the best 420 soil blend and have loads of flowers on the indica plant which is about 24 inches high. The sativas (3 of them) are blooming less and one is downright sad with only a couple flowers but it keeps growing even though it's scrawny. The sativas ever seemed to get to a deep green which is the problem now with all the plants. Their color is more of a light green now in the flower stage. We are in 12-12 lighting and the light is about 6-12 inches from the 4 plants. Is this a possible Magnesium potassium deficiency or...

Any advice is deeply appreciated!
Lalie
 
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