Northern lights, not flowering, just growing, what can cause this?

A customer has a question or concerns and I hope we can get some opinions on it, thanks

“In June I planted my two first seeds. They are not flowering, just growing. This was just a test. The seeds I bought was Northern lights. What can cause this? I have not the best light source yet, but I have ordered a better lamp. Can this be the reason? Feedback would be highly appreciated. As you perhaps are aware of so I’m the rookie of the year. I was using ILGM symptoms checker and it looks like that I have wrong PH values. Some of the leaves turned brown/yellow in the middle. And some of the other leaves looks a little “hungry”? See pictures and details below.”

  • Strain (type, bag seed): Northern lights
  • Soil in pots, hydroponic, or coco?: Soil
  • PH of runoff or solution in reservoir?: NA haven’t got a PH device
  • What is strength of nutrient mix? EC, or TDS:
  • Indoor or outdoor: indoor
  • Light system, size?: Two LED lights generating about 150-200w
  • Temps day, night: 13-17 Celsius
  • Humidity day, night NA
  • Ventilation system (yes/no, size): no
  • AC, humidifier, de-humidifier?: NO
  • Co2 (yes/no): No

What is the light schedule you’re running?


Need to be transplanted asap. Need a larger planter.


Def needs to go to a bigger pot… Roots need to spread out…Transplant ASAP


Transplant into larger pots ASAP. Nutrient lock has occurred. Due to plants being root bound they are focusing on survival. Transplanting into larger pots will allow the plants to survive but due to this issue it will take a few weeks for them to adjust and heal.


transplant is good advice I am still concerned that ph is likely out and you are not measuring in anyway. I am not trying to come down on you so if it sounds that way try to be patient with me as I am not talking out my arse and would like you to have success.
PH control is a huge factor and can make or break any grow I am sure there are people out there who have good luck and have a grow go perfect without attention to PH. I think to be a truly great grower no information is too small ph/tds being major factors in knowing what is there for your plants think of it as a food covered in a spice you hate :wink: If you are starving you will eat it ph controls what plant has for food and the more minerals and options the more likely it stays happy. TDS/PPM is the measure of calories if compared to our diet too much and your health goes down hill too little and you starve plants likewise need enough food/minerals but have poor self control and if it’s there they will try and eat it :wink:
A healthy plant has a healthy diet space to spread it’s roots and plenty of usable light


No offense taken. I just ordered a PH meter, but I have not received it yet. Thanks for feedback. Odd

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Hi, now it’s 24 hours daily, I turned the lights off for 12 hours daily for some time but nothing happend so I suspect that the plant is not “sexually mature” I don’t know the English word.:ok_hand:

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It takes a few weeks after switching the light to 12/12 before it will start to flower. Be sure there are no light leaks in your tent also.


I agree with @Jmesser80, that could be a big part of your problem.

I’m not dismissing what the others are saying, but that stuff will be irrelevant under 24 hours light. And if you had any light entering your grow area, that will definitely keep them from flowering.

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I think those plants need some TLC before you try flowering them. If they’re 60+ days old, they should be ready to flower.

Definitely repot and follow the other advice here. I’d go to 5 gallon pots. Depending on your vertical height available, I’d consider cutting off everything above the 2nd or 3rd node and basically starting again. That upper growth just doesn’t look healthy to me.

Hi, thanks for good advice🙏

Also, what is the distance from your lights to the plants (and what has it been?) They seem to be stretching towards some far away sunshine :slight_smile:

Hi there. Enjoyed your weekend? I have transplanted the plants into larger pots. And I have also adjusted my light source. One of them are looking better already. Anyway I have one question, I the plants are growing in the pots with 24 hours light everyday. Can this have an impact on the THC level? As you know my two plants are approximately 60days each. The biggest is almost 70 cm tall. I was thinking that I would change into 12/12 next Sunday. Do you think this is a good idea? I have also planted 7 new seeds which they all have sprout. When do I put them into a larger pot?

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The healthier your ladies are when they start flower the merrier but keep in mind they will double in size or more during flower :wink:
When dealing with sprouts or very small plants if they are fem/reg there is a really simple rule multiple transplants really simple logic they don’t need much root space to start and are easily over watered. To avoid this I start seeds in rockwool rapid rooters or peat pellets when the roots start popping out I move them to 3" pots or Solo cups then progress to 1-2L pots etc. each transplant is strategic the faster soil dries out the more often I can water/feed my plants the easier it is to adjust ph or flush :wink: it also helps control size of your plants since they will only grow so large in smaller pots but once given new space they grow again, this is quite handy if you like to have several strains and a good rotation of plants. The plants which I don’t intend to flower right away stay small need less nutrients

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Hi sorry for nagging but I when I raise one question and receive answer I have two news ones?:thinking::thinking: You saying that my plants will double in size, is that height and width? Waiting for feedback​:scream:

@The_Odd-one Both mostly height but they will get wider as well

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Lmao :laughing::laughing::laughing: they double in size this means not just height but everywhere some strains will almost triple in height and width for first 2-3 weeks of transition (stretch) plants devote energy to increasing size and height this is a natural selection thing taller bigger plants are more likely to spread seed farther :wink: That being said we don’t want seed this doesn’t mean they don’t by spreading out taller and wider they increase chance of pollen contact. Most growers will take advantage of growth spurt to train plants add nets etc… it is good to note that every strain has different level of stretch and the more plant surface the better potential for yield this is where terms like node spacing lollipoping super cropping etc… come in node spacing is the distance between limbs leafs each node is a potential budding site :stuck_out_tongue: so during veg tight node spacing can be spotted by plants being compact bushy and lush. The node spacing spreads out during stretch but typically a tightly spaced compact plant only doubles making for dense top to bottom buds. Taller further spaced plants need training for similar results

this can be taken to various levels from breaking right at base or mid way it encourages new tops and therefore new nodes :wink: and can done until plant stalks become rigid and brittle


I love growing and help people because I want them to have as much fun doing it as I do so never feel guilt or shame at asking questions :slight_smile: I don’t have to answer I do it by choice as do many others just don’t expect responses to be instant all the time

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switch to 12/12 lighting and check for light leakage, PH water and I would say you would need flower nutrients so they have the energy and the required feed to actually flower. Been vegged so long that soil would be drained of nutrient already and if you haven’t re-potted into a bigger pot probably best to do so too or else it will develop more problems.

Check your watering lift the pot up before you water it and lift it up and judge it by weight and remember that in your head… When the pot feels like it lost over 50% of it weight give it some more but too much watering will give root rot and more drama…

Same as not enough watering. I would read probably another hundred hours of growing through seedling, vegetative growth and flowering and about a thousand hours worth of journals and after all that you should be able to grow something that resembles a plant you looking for hahah but yeah lots to absorb…

For the future though you would like to keep the light a bit closer since it seem to have stretched up way towards the light… But doing better then most regardless! At least you haven’t killed anything hahah chin up you can salvage this! :sunglasses: If you saying you getting stronger lights for flower that will really help but no one mention temperature…

Temperature range should be for flowering 70 to 78 which is their zone or as you were using Celsius it be 21-26c… 13-17c is too cold for the plant and I’m pleasantly surprised it lived and grown to that size under such cold climate. 55-65 isn’t really optimum temperatures. With the bigger light you be in the sweet zone so don’t worry as light will heat up the plant space.

Your plants going to grow 1.5x to 2x the size in flower… Measure how much space you have in terms of height and go ahead and multiply that by 2… Otherwise they will grow into the light. Well I put in my 2cent into this topic hope it helps you and have a bit more confidence!