Possible heat stress or wind burn

Hi,
So we're growing 2 auto blueberrys (2 taller plants) and 2 auto white widows (2 shorter plants) in organic living soil by gaia green mixed with foxfarms ocean forest soil. They were top dressed with gaia greens organic nutrients at week 4 (1 tbsp 4-4-4) and week 6 (2 tbsp 4-4-4 & 2 tbsp 2-8-4, its much less than the recommended amount as it is our first grow and first time working with autoflowers so we wanted to be on the safe side). Each plant is in 5 gallon pots and under a 600w hps (600w mh until flowering started). They had 2 fans, one oscillating and one stationary. We had to tweak the settings on the fans to avoid what we thought was possible wind burn. But now we're in the start of week 10 for most and week 9 for one that started a little later due to a bean not popping. Some parts of 3 of the plants are getting the curled/cupped leaves and only one effected area is the highest point so i feel like if it's heat stress it was from the room being too hot not the light itself. But my question is, do we just leave these leaves until they start dying off since we're close to harvest or should we be removing them? I took a picture to show all the plants are circled effected areas. Please help

If they are dead to the point of being a few days from falling off, just remove. If they are just a bit unsightly but still functional then leave them. It’s hard to tell with you HPS light on, but I wouldn’t remove those.

Southerner said:

If they are dead to the point of being a few days from falling off, just remove. If they are just a bit unsightly but still functional then leave them. It’s hard to tell with you HPS light on, but I wouldn’t remove those.

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Thanks, the light makes it harder to see for sure. But, the leaves look healthy other than curling/cupping minus one with a burnt tip but very little is burnt. And some leaves have precious tip burn from the light during the explosive growth at the start of budding, it grew so fast we couldn't keep moving the light up fast enough but other than that the plants look happy and have "praying" leaves. Part of our problem is we're having an a warmer winter than usual here so it's harder to control the heat as it's upstairs in our house. But it's starting to get colder finally so it's been easier to keep it under 27°C

Heat stress! That dehumidifier can also add a lot of heat to your tent when on!

Blitz35 said:

Heat stress! That dehumidifier can also add a lot of heat to your tent when on!

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Yea, i noticed that. Can the curling be reversed or will that just look like that till harvest/until they fall off? Also, is the a way to have the humidifier produce less heat?

The curling should reverse, they are that way to preserve water..plants shut down in too much heat. As for the dehumidifier, i can't tell you how to set it up as i don't use tents, so i don't vent any air out of my place...but i have the same unit as you, and i know that as long as they are taking moisture out of the air, the air that comes out on top is quite hot! My temps in a 500+ square foot area, went up by 3-5 degrees celsius when the unit removed about 25% of the moisture..the room that it was actually located in, went up a bit more. I sold it this year and decided no more dehumidifier lol.

Blitz35 said:

The curling should reverse, they are that way to preserve water..plants shut down in too much heat. As for the dehumidifier, i can't tell you how to set it up as i don't use tents, so i don't vent any air out of my place...but i have the same unit as you, and i know that as long as they are taking moisture out of the air, the air that comes out on top is quite hot! My temps in a 500+ square foot area, went up by 3-5 degrees celsius when the unit removed about 25% of the moisture..the room that it was actually located in, went up a bit more. I sold it this year and decided no more dehumidifier lol.

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Thanks, yea we're not in a tent actually lol it's a little spot upstairs between rooms that's open so we don't have a inline fan yet (currently have 2 12" fans, one oscillating and one stationary and a big square fan, so 3 total, too combat the 600w hps) but are planning on moving the next grow to a tent in the basement as its easier to control heat down there. Overall, doing well for our first grow and our first experience with autoflowers.

MarijuanaMama89 said:

Thanks, yea we're not in a tent actually lol it's a little spot upstairs between rooms that's open so we don't have a inline fan yet (currently have 2 12" fans, one oscillating and one stationary and a big square fan, so 3 total, too combat the 600w hps) but are planning on moving the next grow to a tent in the basement as its easier to control heat down there. Overall, doing well for our first grow and our first experience with autoflowers.

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All oscillating fans etc do is distribute the heat.

They don’t actually cool anything.

Your leaves are exhibiting heat stress.

And to my eyes you’re not near harvesting time yet.

A good sign your close is that the pistils will recede back into the calyx as they amber off.

Then you look for trich development at this point and you harvest when you feel the tricks are where you want them to be.

Personally I like milky trichs with some amber here and there.

jondamon said:

All oscillating fans etc do is distribute the heat.

They don’t actually cool anything.

Your leaves are exhibiting heat stress.

And to my eyes you’re not near harvesting time yet.

A good sign your close is that the pistils will recede back into the calyx as they amber off.

Then you look for trich development at this point and you harvest when you feel the tricks are where you want them to be.

Personally I like milky trichs with some amber here and there.

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Thanks, i was assuming they were a couple weeks away as the seed bank said 10 weeks from seed to harvest. But, the white pistils are starting to colour and curl in. And we're not experienced enough yet to truly know what the cloudy trichomes look like (i know from research, clear/glass appearance is not ready and that a more cloudy/plastic sort of look is the cloudy trichomes) but we have a jewelers loupe to keep an eye on it. I'm hoping we're about 1-2 weeks from harvest though

MarijuanaMama89 said:

Thanks, i was assuming they were a couple weeks away as the seed bank said 10 weeks from seed to harvest. But, the white pistils are starting to colour and curl in. And we're not experienced enough yet to truly know what the cloudy trichomes look like (i know from research, clear/glass appearance is not ready and that a more cloudy/plastic sort of look is the cloudy trichomes) but we have a jewelers loupe to keep an eye on it. I'm hoping we're about 1-2 weeks from harvest though

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Get a close of up of the cola and we’ll be able to give you an estimate based on structure, swelling, calyx and pistil development etc.

jondamon said:

Get a close of up of the cola and we’ll be able to give you an estimate based on structure, swelling, calyx and pistil development etc.

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Thanks very much. I'll post pictures very soon

So, starting from the top:
First set of pictures are Blueberry #1, on day 65.
Second set of pictures are White widow #1, on day 64.
Third set of pictures are Blueberry #2, on day 63.
Fourth set of pictures are White widow #2, on day 56.
All photos are of the main cola of each plant even if lst caused multiple "main" colas

MarijuanaMama89 said:

So, starting from the top:
First set of pictures are Blueberry #1, on day 65.
Second set of pictures are White widow #1, on day 64.
Third set of pictures are Blueberry #2, on day 63.
Fourth set of pictures are White widow #2, on day 56.
All photos are of the main cola of each plant even if lst caused multiple "main" colas

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I would say you have at least another 3 weeks. Minimum.

jondamon said:

I would say you have at least another 3 weeks. Minimum.

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Thanks. I was hoping it wasn't that long but hey, what can you do lol

MarijuanaMama89 said:

Thanks. I was hoping it wasn't that long but hey, what can you do lol

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They appear to still need to swell which could happen quicker.

Just keep those leaves nice and green and you’ll have a bountiful harvest.

jondamon said:

They appear to still need to swell which could happen quicker.

Just keep those leaves nice and green and you’ll have a bountiful harvest.

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Thanks, yea, we're going to keep a close eye on them. I have a question though. We're doing the 1/2 tsp molasses in the water to help with improved smell/taste and to give it carbohydrates. It says to do it the last 2-3 weeks before harvest. We have been doing it about 1.5 weeks so far. If they take the 3 weeks you suggested, should i discontinue using it after using it for 3 weeks or is it okay to continue until harvest?

MarijuanaMama89 said:

Thanks, yea, we're going to keep a close eye on them. I have a question though. We're doing the 1/2 tsp molasses in the water to help with improved smell/taste and to give it carbohydrates. It says to do it the last 2-3 weeks before harvest. We have been doing it about 1.5 weeks so far. If they take the 3 weeks you suggested, should i discontinue using it after using it for 3 weeks or is it okay to continue until harvest?

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Molasses doesn’t alter the taste or smell really.

It’s used mainly to feed the microherd in organic soil that convert all the organic material into usable nutrient ions for uptake by the roots.

It’s not going to hurt too much to keep using it just watch out for for any issues with your leaves if you over use it.

jondamon said:

Molasses doesn’t alter the taste or smell really.

It’s used mainly to feed the microherd in organic soil that convert all the organic material into usable nutrient ions for uptake by the roots.

It’s not going to hurt too much to keep using it just watch out for for any issues with your leaves if you over use it.

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Thanks. Do you know what kind of issues with the leaves can happen?

MarijuanaMama89 said:

Thanks. Do you know what kind of issues with the leaves can happen?

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Any changes in colour or spots.

Usually with molasses (if it’s unsulfured) you get a decent amount of magnesium, iron and calcium.

If it’s not unsulfured then you’ll also get sulfur.

Too much of these can cause uptake issue of other nutrients.

Just keep an eye on your leaves and don’t worry lol.

I’m sure they’ll be just fine.

The amount you’re using 1/2tsp isn’t very much as long as you’re not mixing that 1/2tsp into 1/4 gallon water.

jondamon said:

Any changes in colour or spots.

Usually with molasses (if it’s unsulfured) you get a decent amount of magnesium, iron and calcium.

If it’s not unsulfured then you’ll also get sulfur.

Too much of these can cause uptake issue of other nutrients.

Just keep an eye on your leaves and don’t worry lol.

I’m sure they’ll be just fine.

The amount you’re using 1/2tsp isn’t very much as long as you’re not mixing that 1/2tsp into 1/4 gallon water.

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It's going into 1 gallon jugs. So i'm sure it'll be fine. Thanks for all your help