Tips of buds continue growing for some reason.

What might be causing this?


Beginning of 6th week of flowering.
1300ppm co2
31C around top colas between lamps and 27C in shade inside of lower crop.
1150W (superlumens) per every 1.64m2
Coco coir
(I had a bit too high ppm for 5th week)

It seems to happen more with buds close to lights for some reason.

It’s called foxtailing. Not unusual. Your average pot snob will turn his nose up at a foxtail bud but it’s as strong and sometimes denser than your average bud

Beautiful looking girls by the way

Weird looking sharp tips. More prone to dry out and bleach when close to lights imo.. and it happens only close to lights - the highest colas.

I'd like to see them more fat but if you think I should not worry, then glad to know. Thanks.

I just read this article about foxtails: https://www.growweedeasy.com/foxtails

.. and seems like it's a sign of stress caused by excessive heat or light intensity. Makes sense. I should upper the lights I guess. I have lots of it.. even thought they're moving on the rails.

It's not the usual foxtailing. This is from heat/light stress.

Ah sorry, didn't read your last post. So agreed, too much energy for that space.

Well let's start with the over feeding, was there a good amount of N in the food?

That combined with the fact it's 90 in the room is the problem.

Try to get those temps down by 10 degrees.

or possibly a light leak

I have 1150W (double ended Philips bulb on "superlumen") per every square meter of canopy area. Lux meter reads around 50 000 -70 000 lumens. I would like to see my plants being more green ideally, but I discovered thanks to this forum that I should be watering coco more often with less PPM. It was usually peaking around 1400-1600ppm and for 1 day on 1 day off type of schedule in 18-24L coco pots. From now on since 1 week ago, I've been doing the watering once a day and have cut off nutes down to 900ppm what usually was around 1500 at this time. I'm analysing rootzone by 1.1:5 extraction method after every 2 watering cycles (just before drip system starts pumping, to be exact) to see how much ppm is there left and I'm trying to hit recommended 550-650ppm as Canna has pointed out in their teqhnicue/practice.

I've been strictly following some company's feeding schedual which I somehow managed to get. It had to work for most of the strains I was told, because they have grown lots of different strains and worked out a graphic throughout many years of practice with Canna brand nutrients.

I have been manipulating with the dosage of main nutrients to my own liking - if leaves were starting to claw or tips slightly burn, then back off and stay, but everything else I kept the same.

Last time I got 1.8gpw which is a big number, so something has to be right for it to happen, but could be also much bigger. I want to be able to truly dial in to exact genetics and environment relation.

I want at least one perfect coco grow to happen before I can move on to RDWC system or Aeroponics. Taking into perspective that I have been able to achieve 1.8gpw by doing so many mistakes, then what on earth could be achieved when mastering coco, or hydroponics or aeroponics?

I imagine 3gpw is not nearly impossible if system is perfect, although it should be done the way that it wouldn't affect quality badly.

I've been gassing until harvest, but I won't anymore. I will reduce it down to 400-600 for the ripening to happen more quickly.

I just love to see what this plant is capable of. Pushing the limits Ok I'm zoning out already. To be continued.

alGrenDh said:

or possibly a light leak

Click to expand...

No leakage, I can assure that.

Lester Beans said:

Well let's start with the over feeding, was there a good amount of N in the food?

That combined with the fact it's 90 in the room is the problem.

Try to get those temps down by 10 degrees.

Click to expand...

Are you saying I should drop temps from 31 to 21? Do you know that co2 will be most effective with intense lights and 30-35 Celsius for maximizing photosynthesis?

Well, I've been keeping temps a bit too high I guess, it was 32C (canopy) until harvest. Outcome wasn't bad either, although I imagine if I would have done it little bit cooler, it would have had better smell.

I'm not willing to decrease temp for more than 5 degrees this time. I'll try slowly reducing down to maybe 25C canopy and see what happens

I hope I won't get too much less grams per watt though.

Why do you ask about Nitrogen? I was thinking Canna AB (main nutes) have the right dose of nitrogen in it. Are you saying if lights are unusually bright, there should be increase in nitrogen % in the mix? What about other nutrients?

Lester Beans said:

it's 90 in the room is the problem.

Click to expand...

The temperature is about perfect for high CO2 supplementation like they mentioned running. Bleaching/white tips is from too much usable light. Do you have an idea of what your leaf surface temps are at cola level? Im thinking the ambient temps and usable light levels may be fine at cola level but coupled with high intensity levels of IR closer to the light source could be causing the stretching.

With the higher CO2 and increased metabolic rate you should be seeing signs of deficiency and not stretching like excess nitrogen "supposedly" causes.

Welcome to the forums FarmerWilly.

Ibechillin said:

The temperature is about perfect for high CO2 supplementation like they mentioned running. Bleaching/white tips is from too much usable light. Do you have an idea of what your leaf surface temps are at cola level? Im thinking the ambient temps and usable light levels may be fine at cola level but coupled with high intensity levels of IR closer to the light source could be causing the stretching.

With the higher CO2 and increased metabolic rate you should be seeing signs of deficiency and not stretching like excess nitrogen "supposedly" causes.

Click to expand...

I have seen leaf temp to be between 26-28C measured with infrared, but I haven't found out about green leaf emission rating which is needed to calibrate this infrared thermometer gun to read more accurately. There is 3 different options or emission ratings to be choosed between: low emission, medium emission and high emission, and they vary a lot in terms of temperature readings. I don't know which one is it, because we're talking about infrared light. Does the leaf shine it back well or not, I can't see.

The cheap one (gun) just reads about 27C, no options.

About the Ir settings you want to use the high setting on the tops of leaves:

"Not all materials emit the same amount of infrared energy when they are at the same temperature. In general, most materials emit more infrared energy than shiny metals do - they have higher "emissivity." (Emissivity is expressed as a number between 0 and 1, with 0 being non-emissive and 1 being perfectly emissive). Reflective surfaces are less emissive than dull surfaces. Weathered or oxidized metals are more emissive than polished, shiny metals.

If you need to take temperature readings on low emissivity objects regularly, consider an IR thermometer that enables you to compensate for variations in emissivity. For example, the Fluke 561 Infrared Thermometer enables you to set emissivity to "High" (for measuring most surfaces, such as wood, paint, rubber, plaster, or concrete), "Medium" (for oxidized metals or granite, for example), or "Low" (for shiny metals)."

How about your lights on and lights off temp difference? That could cause stretching if it varies a decent amount.

Lester Beans said:

Well let's start with the over feeding, was there a good amount of N in the food?

That combined with the fact it's 90 in the room is the problem.

Try to get those temps down by 10 degrees.

Click to expand...

Plants exhibit stress in several ways....leaves, fox tailing, heat, cold, over fertilized, lock out.....other visual cues to watch.

I run a sealed room with CO2, AC & DeHuey..

I only get foxtailing if my temps are too high or the plants have too much food.

In my experience, most plants I work with prefer a canopy temp of less than 80 degrees in flower. Typically I shoot for 78-80 in early flower (weeks 1-4), and then dial down to 74-78 in late flower (weeks 5-10)..

I also cut down CO2 to 300-500ppm the last two weeks.

I use the plants as a guide and let them tell me what they like.

Best of luck with future endeavors!

Heat from the lights.

I don't think it's understood why this happens. However, if energy from the lamp heats the plant, the plant gives off more energy in the form of heat. Literally, energy that should of helped grow the plant, is leaving again. So we have a higher proportion of far/infra red around the buds. Which is a shade response trigger.

I am totally making this up as I go. Except the bit about it being heat from the lamps. I have seen it many times, looking just like that.

The signs of high feed arn't there.

The pictures seem to show healthy growth with only the tallest nugs on the plant exhibiting the stretching, its gotta be heat/IR at top canopy level. If you cant raise your lights any higher, you could use the height at which the plants begin to foxtail as your known max plant height to work with and adjust veg time and strain stretch/plant numbers accordingly.

It’s not foxtails

It’s senescence