Leaf curling - any thoughts?

Hey everyone,

Plants are growing nicely, but the top leaves are curling quite profoundly, especially in the evening.
Here in Madrid (Spain) the temperature has soared quite suddenly, we're looking at about 35º (centigrade) for the next couple of weeks - not to mention the coming summer. Previous years though I never had this issue, so thought I'd take it to the experts.
Any thoughts on why this might be taking place? It's happening most to my Cali Hash and Blue Widow (from Dinafem).
Only 1 dose of nutrients so far 2 weeks ago, they're still babies (planted March).

Cheers guys!

What is that your using for a medium?

looks like volcano rock

Hi hexthat, yes, volcanic rock. Would that be the issue?
Never had this problem last year using volcanic rock (spares the soil from the burning sun).

I had curling issues this summer. My problem was high temp's and inadequate drainage, which caused my soil to retain too much moisture. Your problem doesn't look too bad. If you are veggin indoor and your temps are above 29.4c than you should try and lower it, or else put the plants outside. They deal with high temps better outside than inside.

Thanks Kaloconnection - appreciate the time.

maybe this can help. http://www.growweedeasy.com/marijuana-symptoms
I have never seen a plant grown in volcano rock.

Hi everyone, quick update on the plants. I've now taken off the volcano rock - seems it wasn't helping matters. Just hope it's not too late. I'm seeing further curling of the leaves and now dark spots on the lower leaves which are now properly yellow. Not sure if the plants (those in the pictures) will survive or not, I have a nasty feeling they won't.

Any ideas on what I could do? Transplant the soil? Nutes?

Thanks as always to everyone on their input. Wish I could support others, but still a newbie at growing!

Thanks BLVDog - really interesting site. Think mine have Boron and possibly iron deficiency. Trip to the garden centre it is!!

they llooked really good in those volcanic rocks very nice ganja green and very healthy.. i think you transplanted in soil? the leave cural could mean you need more circulation try to have air flow around ganja plants and also they are starting to yellow up they may need a feeding, start feeding at half does of required nutrients and as they get bigger you can work your way up on feeding more.

Hey blaze530, thanks for the reply. I agree they look good with the volcanic rock, just not sure if it's the right thing to do. I just removed them from the top and put some fresh soil down.

Been scanning through this forum and web and haven't found anyone else doing it - I suppose there must be a reason for that! I just thought it would keep the blazing sun from scorching the soil too much. The summers here in Madrid are brutal, and while the plants love it, not sure the soil feels the same as it's always bone dry at the end of the day, which means more watering. Think I was getting into a bad cycle of watering all the time to compensate.

Will definitely get some nutes in there and possibly transplant the soil if they don't recover. Will keep posting updates on here with pics.

Growing weed is bloody complicated stuff!!

i wanted to read your posts but that penguin is too fucking cute

It's a bloody cute penguin!!

roamingrichy said:

It's a bloody cute penguin!!

Click to expand...

it sure is. i still watch madagascar movies ....i need a life apparently LOL

People use cinder (volcanic rock) for growing here in hawaii all the time. Usually it is mixed with other amendments. I would maybe try and incorporate the cinder with your soil mix, as the soil looks like it is lacking an aeration amendment(most people use perlite). Roots like air and dont like sitting in stagnant soil with poor drainage, that can lead to curling leaves.

Try poking some small holes around the base of your pots to increase the oxygen intake to the root zone. Don't water until your pots feel light, and make sure when you water that your plants dont sit in the run off water.

If you have a strong fan blowing right at your plants, try moving it further away so the plants still get good circulation but arent getting blasted with wind. That can cause curling as well.
What are your temps like where your plants are?

Hey kalo, thanks for the reply.
Interesting point about the wind, never thought of that. It's been bloody wind here recently and the plants are all outside facing the elements. My terrace is a sunspot, but the wind get blow a gale sometimes.
I wonder if what's happening to my weed is also what's happening to my tomatoes. Never have I had such rotten luck with tomatoes. The one's in the pictures as you can see also have curled yellow leaves. All plants are in the same soil (well aerated and perlite on the base to prevent rotting). I know this is a weed forum, but I'm sure you all grow other stuff too.

In terms of temperatures, it's been approx 26-30 during the day and down to anything from 15-9 at night. That's celcius by the way,

Anyway, let me know what you think.
Cheers

You said 2 months old? I am willing to bet the slow growth is from packed or caked soil. It looks like you have very little perlite in your soil mix. I mix my soil with 30% perlite added in all the soil not the bottom. When your soil packs it does not let your roots grow right making very slow growth. No oxygen can get to the roots. I would get some good soil and perlite and transplant them. Being two months old they should be much bigger.

When you water your plants does the water take long time to drain thru the soil?

water stress

Hi 5150, thanks for your reply.
Funny you should mention that - the water does take a long time to drain through!
Right - a transplant needed tonight with some fresh soil and perlite.
Cheers for the tip!

Quick question though - once I do transplant them, what are the chances of them becoming much healthier plants and growing the way they should?
Not sure if it's already a lost cause and worth investing the money.
Thanks