Advice needed with curling leaves

[lycheetrees]

Hello. Im lycheetree and I have problem with - up curled - leaves.

So I have Power Plant (PP) Northern Lights (NL) and ThinkDiffrent (TD) in my grow box.

NL and TD are doing just fine.

PP recived too much nuts and the leaves started to burn. I flushed the PP with demineralized water.

Ph in PP pot dropped to 5.0 now is getting to 6.0 and the aim is to reach 6.5.
I had used dolomite (calc+Mg) mixed with water to increase Ph and gave it to the plant 2 days after flushing it to prevent more nuts burn.

I had reduced wind and put the lamp bit higher for the PP.

I am worried about massive upper leaves curling up nearly to a tube. But also new grow tips are bending down. And at this point I would love to recive some second opinions.

I think after flushing it have some transpiration problems and bending upwards but no clue on the new tip leaves to bend down. It is like it have too much water and to less water at the same time

So it might be the mix of over watering, 2much direct wind, over heat, and low ph... I started from reducing wind and heat then the PH fixing and now i wait but im worried about that upper curled leaves which will die if i wont react..

 

[Fuzzy Duck]

Re: Advice needed with curling leaves.

Welcome to forums

I'm sure several members will share their opinion on the matter at hand but its always worth while double checking or doing a little research your self on such opinions to further your own knowledge before making up your mind... even the best of us get it wrong some times

Now we may require a little more information to help, i may not cover all areas so feel free to answer other members questions !

1. To me it looks like heat stress.

So i'm going to ask what type of bulb are you using, total wattage of the bulb & what was the hanging height to what is now after you adjusted it ?

Also average lights on temperature please.



Now the thing is you are growing few different strains which makes things a little more complicated too work out as every strain may require a different amount of nutrients either being sensitive or over hungry so to speak, so a regular feed of nutrients at said dosage may well be suitable for most but not for some... which may lead to nutrient burn or under feeding depending on strain requirements or understanding of it.

So PP sounds like its a little sensitive to the nutrients i would suggest lowering nutrient dosage when feeding this plant to prevent burn when compared to feeding other plants.


I'm not to sure about any PH problems as of yet, you have not mention what you are growing in ?

If soil please state brand name of soil/compost & if it mentions PH of the growing medium please add.


Nutrients used, quantity per feed may help, brand name & whether you are feeding every watering or whether the nutrients are organic may help also



Regards - Fuzzy

 

[Jimmycricket]

Re: Advice needed with curling leaves.

to me it looks only like heat stress.

 

[lycheetrees]

Re: Advice needed with curling leaves.

Hello.

So the lights are two GIB lighting Flower Spectre HPS each 150W.
The temperature of the bulbs can reach 200 C so the fan is cooling them and the growbox temperature is 30-35 degrees and the lights hangs 35cm above the plants.

The soil is all purpose soil with added minerals for all kind of plants and it had 5.0 - 6.5 PH level mentioned on the bag which i dont have anymore so the brande name and details of the soil are gone. Plants are growing in 12liters buckets with 1 part of perlite 1 part of dolomite and 10 parts of soil.

The nutrient source is biohumus forte made from californian earthworms droppings or stools And i am using 50ml per 1 liter like on the bottle info. It is organic-mineral and there is smtnhg like that here : in % (m/m) minimum 0.5% of N and 0.5% K. This one is super safe i think but no P in it.

In addition to supply the plant in P i used terrible BioStos NPK 4-6-5 concentrated fertilizer for ferns. And the proportions was 2.5ml per 2 liters. After using that the leaves started to burn. So it is a no-no

After leaves showed nuts schock and started to dry I used the MAgnesi Sulfas.

Today I plugged the ultrasonic humidifier in which i put 2liters of water with 20ml of Biohumus and half of the table spoon of the Magneesi salt and I think the plants responded nicely but the PP is still curved but started to grow as well coz it was in lag.

Also with the TD salvia plant the internodes are not so tight as I would like to see them. So I have no additional source of P so maybe that is the reason? And what I can do to make the steams stronger is they apper to weak.

The photo shows TD big internodes and the female strings(dont know the real name 4 that). The TD is automatic seed - 3 weeks old and already with the white strings. Is it not to early?

I will add natural color photos at the evening when the guests will gone.

 

[David Bowman]

Re: Advice needed with curling leaves.

to

I agree with Jimmycricket that it is probably due to heat stress. 30-35 degrees C, 86-95 degrees F, is too hot without supplemental CO2, try to keep it at or under 30 C. You didn't mention it but if you do not have any fans for air circulation that would go a long way towards reducing the heat stress on your plants as well.

 

[lycheetrees]

Re: Advice needed with curling leaves.

Great. Lowering the temperature will be super easy and hopefully it will be enough for the plants to thrive.

 

[Fuzzy Duck]

Re: Advice needed with curling leaves.

Cheers for the additional info

Certainly looks like we are on the right tracks with the heat stress, with temps that high i would suspect lack of ventilation to which i'm pretty sure you are working on pretty soon.

Air flow or exchange of air is quite important for plants as they do need to breath to which many of us get away with a passive vent at the base of the tent & use an active inline fan at the top the tent to extract the warm air with the warm air vented out side of grow room area as not to recycle the heat and cause further issues.

Oh ye, you can get the light a lot closer i'm reasonable sure a 150w bulb will be safe at 15 cm to 20 cm easy other wise the greater the hanging height the less light the plant recieves this is basically governed by the inverse square law of light effect... cool ah & that is some home work for ya !


Moving onto soil...

Mmm not to impressed with what you told me about the bag of soil/compost so far... PH 5 to 6.5 is a little questionable to me !

Ideally your PH should be between PH 6 & 7 (sweet spot is about 6.5 to 6.8) this is where a majority of nutrients is most available for the plant to use, its the PH of the soil/compost which is the important part !

Here's a little chart i like to what I find better than most i've seen out their, i'm beginning to use this chart to help understand nutrient deficiencys better

If you wish to continue using said brand of soil/compost i would be incline to amend with dolomite or garden lime to buffer the PH value up towards PH 7, as you can see from the chart above and what could be a variable PH nature per batch of compost you going to run into problems under PH 6 with the soil/compost used !

If concern about the PH value of soil/compost used you could top dress surface of plant pots with lime & gentle rake into the surface followed by a watering, but would only go that far after testing soil/compost first with a PH probe which can be purchased from most good garden centers or those big shop things in america called depos or what ever.



Mmm TD big internodes & stuff, well that is more likely a strain genetic thing vs indica/sativa dominate traits... ya got a fair few different strains going on their and they certainly don't grow all the same !

Just wait in till you start flowering & see the stretch occur between the different strains

 

[KingJohnC]

Re: Advice needed with curling leaves.

Your leaf damage appears to be from heat stress and a small amount of nutrient burn. 35° Celsius it too warm for your plants. You want 20°-30° Celsius and 50%-70% humidity for vegetative growth and 30%-50% humidity for flowering. You want pH 5.8 for hydroponic and soiless (peat moss and coco coir) and pH 6.5 for soil.

here is a nutrient availability chart

here is a cannabis leaf deficiency chart

here is the Cannabis Plant and Pest Problem Solver and the Plant Abuse Chart

Cannabis Plant and Pest Problem Solver - Pictorial

Plant Abuse Chart


I recommend when you add nutrients to start with a 1/4 strength dose and to see how your plant reacts to them. If you notice yellowing and browning tips on your leaves that is a sign of nutrient burn and to slightly reduce the amount of nutrients you are feeding.

Here is a guide on nutrients and how to use them.

Nutes - What To Use & How To Use Them - Tutorial

 

[lycheetrees]

Re: Advice needed with curling leaves.

Thank You guys for all the support. It is mine first home grow and Your advices are super accurate.

I am rather book guy. Do You know any book that is as good as 420magazine.com/forums? Or close to it?

Best regards, Paul

 

[Jimmycricket]

Re: Advice needed with curling leaves.

Thank You guys for all the support. It is mine first home grow and Your advices are super accurate.

I am rather book guy. Do You know any book that is as good as 420magazine.com/forums? Or close to it?

Best regards, Paul

Growers bible has a lot of good stuff in it.