What to do after flush? Nitrogen deficiency

[LeonardLunte]

Strain: Royal Dwarf Auto
Ph Water: 6.5
Nutrients: 2ml/L Biobizz Grow, 1.5ml/L Bloom, 0.7ml/L CalMag
Soil: Biobizz Light mix
Pots: Fabric Pots 7L
One is 5 weeks old and the other one 6 weeks.

Hi, Ive been battling what I suppose is a nitrogen deficiency for a couple of weeks now. In the beginning I only had some yellow leaf tips but now my leaves at the bottom are dying off on after another. My plants are in early flower so I think theyre still to young to be cannibalizing leaves like that. After 2 weeks of contemplating because I was scared to stunt their growth, I flushed my plants yesterday with about 20L of 6.3-6.5ph water, since I suspect the Nitrogen deficiency is because of a lockout.

I just want to know what the smartest way to proceed would be.
How much nutrients should I give? Ive been giving them only half of what the nutrient schedule advises. I also didnt give them any nutrients when I flushed.
I will attach some pictures of the affected leaves.
I think the brown spots are from a calcium deficiency I was having in the beginning of my grow, It seemed to have disappeared since I gave them CalMag but now its coming back and I dont understand why. The brown spots also are only on the lower leaves that have the yellowing.
This is my first grow and now I have tried pretty much everything I found in online tutorials, I dont know what to do at this point. I also feel like my older plant (or both) is a bit behind on bud production, what do you think?

(DSC_0203 is the 5 weeks old plant, DSC_0202 is the 6 weeks old plant, DSC_0204 are the affected lower leaves that are dying on the younger plant, DSC_0198 are the affected lower leaves that are dying on the older plant)

 

[AdaminCO]

Isn’t light mix considered coco?

 

[LeonardLunte]

Isn’t light mix considered coco?

biobizz light mix is soil, its light mix because it has very little pre installed nutrients. They last for about the first week or two and then u can give nutrients yourself

or what do you mean?

 

[Stunned]

Plants can be very individualistic even within their own strains.
Example, I have 2 plants of the same stain
One requires more N than is indicated on the feed chart and one less than on the feed chart.
At the fifth week of veg one was getting only 1/2 the recommended dose and the other was getting 1.5 X the recommended dose.
You have to adjust feeding based on appearance and response of the plant.

 

[Emilya Green]

Strain: Royal Dwarf Auto
Ph Water: 6.5
Nutrients: 2ml/L Biobizz Grow, 1.5ml/L Bloom, 0.7ml/L CalMag
Soil: Biobizz Light mix
Pots: Fabric Pots 7L
One is 5 weeks old and the other one 6 weeks.

Hi, Ive been battling what I suppose is a nitrogen deficiency for a couple of weeks now. In the beginning I only had some yellow leaf tips but now my leaves at the bottom are dying off on after another. My plants are in early flower so I think theyre still to young to be cannibalizing leaves like that. After 2 weeks of contemplating because I was scared to stunt their growth, I flushed my plants yesterday with about 20L of 6.3-6.5ph water, since I suspect the Nitrogen deficiency is because of a lockout.

I just want to know what the smartest way to proceed would be.
How much nutrients should I give? Ive been giving them only half of what the nutrient schedule advises. I also didnt give them any nutrients when I flushed.
I will attach some pictures of the affected leaves.
I think the brown spots are from a calcium deficiency I was having in the beginning of my grow, It seemed to have disappeared since I gave them CalMag but now its coming back and I dont understand why. The brown spots also are only on the lower leaves that have the yellowing.
This is my first grow and now I have tried pretty much everything I found in online tutorials, I dont know what to do at this point. I also feel like my older plant (or both) is a bit behind on bud production, what do you think?

(DSC_0203 is the 5 weeks old plant, DSC_0202 is the 6 weeks old plant, DSC_0204 are the affected lower leaves that are dying on the younger plant, DSC_0198 are the affected lower leaves that are dying on the older plant)

You have flowering plants there... and in bloom the needs for Nitrogen are not as much as the needs for potassium and various other things. I see an obvious potassium deficiency in your leaves as the major problem. I say obviously, to make a point, that it takes some amount of experience to be able to read your plants and see what is causing a problem like this. You have now seen your first potassium deficiency. It starts from the bottom and does that weird elongated tip burn on some of the leaves while wiping out the lower leaves as it is doing. Potassium, Nitrogen and Phosphorus are known as mobile nutrients within the plant... or nutrients that the plant can store and move around when the new growth demands more of it than is being supplied. When K is being cannibalized, it looks like this. When N is being cannibalized, instead of the distinct pattern we see here, the entire leaves begin to yellow, and just like this one, because it is a mobile deficiency, it moves from the lowest leaves first and then upward toward the top.

Someone told you one of the 4 big Auto marketing lies, that Autos need fewer nutrients than any other plant of that size. You now see the effect of acting on that erroneous information by feeding half strength. Truth be told, Autos are an extremely aggressive plant and prolific grower, and they can use just as many nutes as a any other cannabis plant of its size, sometimes more!

Now you flushed, and made the problem worse, by again, and this time aggressively, not feeding your plants, not even half strength. Flushing it turns out, is not the be all and end all cure that some make it out to be.

You need to feed this plant whatever is recommended by your nutrient company. Do you really believe that they have never seen an Auto before, and have no idea how to recommend feeding them? Look around, and I defy you to find separate instructions for Autos vs Photoperiod plants in the various feeding charts. You have become yet another victim of the Auto marketing hype.

Feed the plants the recommended amount for their age and size. A little bit of a nutrient overload tip burn would be much more desirable than what is happening now. I am sorry that the online tutorials don't make any of us instant experts, so it is going to take a grow or two to start really feeling comfortable with all this. Please never hesitate to come here and ask questions. This forum is a very special environment rarely seen in the online world and the multiple experts around this place act as a check and balance against each other, and in the discussions that ensue, the truth usually comes out and your issues get solved. Finding information online is all about finding the right experts to ask and then knowing the right questions to ask, and if you are in the right place the answers will usually come with some additional knowledge to help you along in your journey.

Good luck... I hope this helped.

 

[LeonardLunte]

You have flowering plants there... and in bloom the needs for Nitrogen are not as much as the needs for potassium and various other things. I see an obvious potassium deficiency in your leaves as the major problem. I say obviously, to make a point, that it takes some amount of experience to be able to read your plants and see what is causing a problem like this. You have now seen your first potassium deficiency. It starts from the bottom and does that weird elongated tip burn on some of the leaves while wiping out the lower leaves as it is doing. Potassium, Nitrogen and Phosphorus are known as mobile nutrients within the plant... or nutrients that the plant can store and move around when the new growth demands more of it than is being supplied. When K is being cannibalized, it looks like this. When N is being cannibalized, instead of the distinct pattern we see here, the entire leaves begin to yellow, and just like this one, because it is a mobile deficiency, it moves from the lowest leaves first and then upward toward the top.

Someone told you one of the 4 big Auto marketing lies, that Autos need fewer nutrients than any other plant of that size. You now see the effect of acting on that erroneous information by feeding half strength. Truth be told, Autos are an extremely aggressive plant and prolific grower, and they can use just as many nutes as a any other cannabis plant of its size, sometimes more!

Now you flushed, and made the problem worse, by again, and this time aggressively, not feeding your plants, not even half strength. Flushing it turns out, is not the be all and end all cure that some make it out to be.

You need to feed this plant whatever is recommended by your nutrient company. Do you really believe that they have never seen an Auto before, and have no idea how to recommend feeding them? Look around, and I defy you to find separate instructions for Autos vs Photoperiod plants in the various feeding charts. You have become yet another victim of the Auto marketing hype.

Feed the plants the recommended amount for their age and size. A little bit of a nutrient overload tip burn would be much more desirable than what is happening now. I am sorry that the online tutorials don't make any of us instant experts, so it is going to take a grow or two to start really feeling comfortable with all this. Please never hesitate to come here and ask questions. This forum is a very special environment rarely seen in the online world and the multiple experts around this place act as a check and balance against each other, and in the discussions that ensue, the truth usually comes out and your issues get solved. Finding information online is all about finding the right experts to ask and then knowing the right questions to ask, and if you are in the right place the answers will usually come with some additional knowledge to help you along in your journey.

Good luck... I hope this helped.

Thank you so much! This really helped and makes sense. My last question now would be If I should wait until the soil has dried to feed again, (which will probably take up to a week since I just flushed them with 20L of water), so I dont overwater them or just feed them ASAP?

 

[Emilya Green]

No matter if you flushed them with just enough water to produce runoff, 20L or if you had poured the entire Pacific Ocean through that container, the end result would be that the soil can only hold exactly the same amount of water that it could hold on any normal watering. It is IMPOSSIBLE to overwater a cannabis plant by giving it too much water in one session. The ONLY way to overwater a cannabis plant is to water it too often. If you normally water before the plant has had a chance to use all of the water suspended in the soil, all the way to the bottom of the container, only then are you are overwatering. Your soil won't "dry out", it must be understood that the plant is using this water... it is not simply evaporating. Your plant is going to use all of the water in there in just about the same amount of time that it would normally take.

That being said, your plant is being forced to cannibalize itself due to starvation. Can you justify waiting another 3 days and suffering more damage? Life will go on if you do, but I do think it would be better to get the plant fed asap. The problem is that you have that huge column of water sitting there, and trying to displace it with nutrient water would take more water than I would like to contemplate, so lets take advantage of the physical nature of this plant.

There are 2 sets of roots in a weed... the bottom feeder roots that we see when we transplant, and also a top mesh of fine roots that are called spreader roots. These special roots are what classifies this plant as a weed as they travel just under the surface of the soil and spread out away from the plant, and in our containers about 3-4 inches down. This mesh of roots makes our plant a predator, and weeds can steal a quick rain away from surrounding vegatables, choking them out of needed water and nutrients. You can take advantage of these spreader roots by giving just a tiny amount of water, like a morning rain, just trying to water the surface and about 3" down. This will allow you to get some nutrients in there as early as today, while you wait for the plant to drain the water from the flushing. Every 3 days, until that container is dry enough to fully water again, give her some more. When it comes time for a proper watering, either 3 days from now or 5 or 7, give her a full load of nutrients again and let her catch up. By then it should be clear how well she is tolerating the nutes, and you can go back to nutes every other time with proper watering techniques and I suspect you will be fine.

 

[LeonardLunte]

Ok, I will try and do that. thx for sharing your knowledge with me!

 

[AdaminCO]

You’re in good hands my friend... you can take what she says, and take it to the bank.
...As always, thanks Em.

 

[LeonardLunte]

Hi, I wanted to come back to this thread because I feel like my plants are still dying . I did as u said with the Morning rain thing, I gave them about 300-400ml of nutes right after we chatted here. Yesterday I fed them with 2-3L each with the dosage of nutrients it says on the nutrient schedule. Between yesterday and the 300ml my plants developed a lot worse symptoms, its clearly a K deficiency. They stretch like crazy and the buds still are pretty tiny for their ages. I looked up a lot of tutorials but everybody just says flush or feed more nutrients. I just wanted to come back here to ask if anybody has another idea what I could do now to help battle this, I hope it wont completly destroy my yield...
Would the best thing to do really just be to wait till the next feeding? Over night they got these brown spots on the upper leaves. Thx

 

[Emilya Green]

I think your plants look a bit better, but you are right, the potassium thing is progressing. Let's adjust pH and check that you are adjusting your pH AFTER you have added nutes and supplements to the water. Also, are you doing feed/water/feed/water, alternating each time the plant uses up the water? I have never agreed that 6.5 is the correct pH to adjust to... try adjusting to 6.3 next time and lets see if we can stop this from progressing. The damage that is now showing is not going to go away, but we can stop it from getting worse and not affect your yield.

 

[LeonardLunte]

I always adjust ph after I mixed the nutes. Normally in the 6.1-6.5 range, the ph of the drainage is 6.3 if that matters. What exactly do you mean with feed/water/feed/water, just that I should not feed everytime I water? Its probably best to just wait and see how the plants react to the nutrients i gave them yesterday, since its the first time I actually gave them a lot of nutrients at all. Im just kind of scared because it just doesnt seem to stop and it came so suddenly, also looks pretty unhealthy... Thx for your help.

 

[Emilya Green]

In soil, if you feed every time you water, the nutes will build up in the soil and lockouts will begin to occur. Soil has the ability to hold nutrients, so nutrient companies take advantage of this to allow you to feed with a fairly strong mix of nutes, and then when you come along the next time the plant needs water, and you adjust the pH of that water to 6.3, just like you do with the nutes, you reactivate any nutes left in the soil and they become available to the plant. This very efficient system allows you to give the plants a strong dose of nutes and then taper back, allowing the plant time to use the nutes you have provided.

If you have been giving your nutes every time, this is probably part of the issue. Start running this like a soil grow, not a hydro one.

Also, no the pH of the runoff means nothing.. it is a total waste of time to measure it in soil. Think of a coffee percolator... the more water you run through the grounds, the weaker the coffee. At what point of runoff, 2%, 10% or even 20%, does the reading approach anything to do with anything in the soil above. The answer is no where... the reading and when you take it is totally arbitrary. Soil pH is totally misunderstood by most anyway. Soil has a base pH... where it reverts to when it is dry. When you water, the column of water that you suspend in that soil takes over... the soil is at whatever pH you set your water to. The buffers in the soil start to work on that water, and it does start to drift up slowly from the 6.3 that you come in at, but it is only when the soil has gone dry that that region of the container achieves the base pH of the soil. Depending on how wet the soil is where you might want to check the pH, the reading will be different in different parts of the container.

 

[LeonardLunte]

ok! Since I gave them the nutes on friday, I think they are getting back on track. The buds seem a bit frostier and the stems of the leaves are fading back to a green I feel like, before all the stems were a bit purple, it probably has something to do with the issue. Next time I will just feed them with ph water as you said to reactivate the nutes.

 

[LeonardLunte]

Do you know what the brown spots could be? Theyre getting more and more everyday, only on the older plant, seems like the yellowing mightve stopped/slowed down though. The younger plant seems to be fine now, at least I cant see any differences over the past days. I suspect the brown spots might be a cal mag issue? Or does it have to do with the Potassium thing... I didnt feed cal mag since I flushed.
Im sorry for all the questions, but the answers I got here so far just seem to have helped the most and I feel like opening a new thread everytime I have a question about this specific issue would be kind of inefficient right?

 

[Emilya Green]

Yes, being up there in the upper leaves, it is a calcium issue. This is very common and not an extra concern really, but yes, now is the time to give calmag, and I would give a good dosage on the affected plants each time you water. Its ok about the questions, because as we peel back the layers of what was going wrong, these other issues are now coming forward. No worries... you got this, and the plants are looking a lot better today.

 

[LeonardLunte]

The younger plant is doing fine now and is growing good. The older plant however developed this new thing over the last two days and it looks really worrying... definitly has to do with the brown spots that started showing up on the upper leaves, it also only appears to be at the upper leaves. Yesterday when it was time for the watering I also fed them a dose of calmag. I had a fan pointing at them do you think this is wind burn? It looks very bad and in 2 weeks is supposed to be harvest, is this fatal?

 

[Emilya Green]

Now in addition to the calcium, your plant is showing a non fatal potassium deficiency. It is not the fan causing that, because fans are a good thing and will only occasionally cause very recognizable wind damage... this is not that. If you have a finishing nute that is high in P and K, now is the time to give it.
That being said, we may have identified a reason now for these sudden deficiencies of various kinds... you are just now giving nutes to these hungry plants. In holding back of their nutrition, there are few reserves built up in the leaves for these macronutrients now being craved. Since everything in a grow is cumulative, this probably could have been avoided with proper feeding all along and the plants likely wouldn't have been on such a razor's edge.

 

[LeonardLunte]

Okay thank you. I have another grow of jamaican pearls which are in their 3rd week of veg and I basically applied everything you said so far to this point as good as I could and they look really good. Nice green and no deficiencys etc. I guess you learn with every grow I only have Biobizz grow, bloom and calmag right now. I think ill just give a bit more bloom in the next feed since that probably has the most K and P right? Thank you, the buds are looking pretty good in comparison to the leaves and they also smell nice, hopefully I can learn from the mistakes I made and apply that knowledge to my other plants and hopefully I can also harvest in the next 2-3 weeks

 

[LeonardLunte]

is there a point in cutting of the super brown leaves at the top? Ive heard that dead leaves attract pests but ive also heard cutting of leaves isnt good for autoflowers, Im also not sure if these classify as dead leaves? They look pretty terrible and they crumble to the touch but the plant wont let go of them by herself, Id have to cut them off.

I think Ill also drive to a grow shop nearby soon and see if they have something with a lot of K. My pearls, who looked perfect till now, are now showing signs of a K deficiency too and I dont understand why. I always gave them nutrients like the schedule says. Nutrients, Ph Water, Nutrients.. Since all the pearls are still in veg Im only giving grow nutrients and calmag. Should I feed Bloom even though theyre all still in veg, and probably will be for the next 2 weeks or so, because bloom nutrients got more K right? As I said I guess just going to the grow shop and picking up something with a lot of K is probably the best idead. Ill attach some pics of the Jamaican Pearls, theyre 4-5 weeks old in veg. Since its been going so good with those Im really scared now that theyll turn out like the dwarfs did.

On all the pearls only 1-3 of the lowest leaves are affected yet. I also didnt water them for a bit too long and didnt notice, the lower leaves were drooping pretty hard but when I watered them they turned normal again. I also attached a pic of the current setup in the tent, In the front are the two dwarfs in flower and in the back I got the 3 Pearls in veg, the biggest one in the middle is 5 weeks now they two on the sides are 4. All of them have some spots on the lower leaves on some it just seems a bit more progressed.

Maybe I should start a new thread though since these are different plants.. Sorry if Im violating any forum terms lol also sorry for the bad quality pics of the leaves..