Easy Ryder leaf tips curling ... ?!?!?!

[dtownscience]

I'm on day 31 now of my grow. The tips of the leaves are curling, but only on my Lowryder II X AK47 plants.

My canopy temps are in the upper 70's to low 80's, never over 85. I've been careful not to over water. As you can see on one of these plants the budding has been severely affected. I've given them 1/4 strength flowering nutes, once, and molasses. I've also tried moving the lights up. On the shorter plant, the light is a full 3 feet away. Any ideas?

Also, you can see my whole grow in my signature, i've tried to keep good details.

 

[Night Claptoman]

whats your medium and PH?

 

[dtownscience]

whats your medium and PH?

FF Ocean forest, didn't add nutes until after 2 weeks.
PH is 6-6.5

and like i said, the other plants (strains) seem to be fine

 

[mared juwan]

What the N-P-K of your nutes? Looks like too much nitrogen for that plant. Way too much. Strains respond very differently to nutrients.

 

[dtownscience]

What the N-P-K of your nutes? Looks like too much nitrogen for that plant. Way too much. Strains respond very differently to nutrients.

I used Fox Farm Grow Big and Tiger Bloom. They are 6-4-4 and 2-8-4.
The veg nutes were applied twice, at 1/4 then 1/2 strengths. flower nutes once, at 1/4 strength

 

[mared juwan]

OK the dark green color and the downwards curling/canoeing of the leaves are sure signs of too much nitrogen. You'll need to flush the pot out really well to get out whatever is in there. The leaves will never flatten out unfortunately as you can see they have actually grown into this shape. Just monitor the color of the leaves and when they begin to lighten up to a healthy green you can start to feed again. Until then I would do plain water because any more nitrogen will make the problem worse.

 

[dtownscience]

You'll need to flush the pot out really well to get out whatever is in there. ... Until then I would do plain water because any more nitrogen will make the problem worse.

Okay, I flushed out the two plants that were looking woeful, with 3x water to soil ratio. Is blackstrap molasses okay to add? Also, what about adding 1/4 dose flower nutes after the flush? I know you say any more nitrogen would be bad, but the flower nutes are low nitrogen, and I've just flushed, and the buds are looking weak and underfed. What do you think?

 

[mared juwan]

I'm not certain exactly what you mean by the buds looking weak and underfed. Looks like your plant is pretty early in flower and all plants go at their own pace. Just know you have a strain that is super sensitive to nitrogen. I grow a lot of different strains and I use the same general nute levels with 90% of them. However, the other 10% just can't handle the nitrogen. The leaves get really dark green and curl up like yours. The only way I've ever improved the problem is by cutting out any and all nutes with nitrogen in them. It's easier for me though because I use a two part base which has nitrogen and then also P-K boosters which have no nitrogen at all. So if I ever get nitrogen toxicity I flush like crazy and then feed only the boosters. My boosters are 0-2-4 for first half of flower and 0-5-6 for second half. So if you are gonna use something that is 2-8-4 just be mindful of what the numbers mean and how they will affect your plant.

The three numbers in N-P-K will do very different things and are processed by the plant in very different ways. The Nitrogen (N) component is what will "burn" your plant when applied in excess. The plant will consume ALL nitrogen you give it. It doesn't know when to stop. This will cause accelerated growth for a short while before eventual toxicity and burn. What you are seeing is the plant trying to use all the nitrogen it has been given. The leaves are growing beyond their intended shape causing them to curl. Nitrogen is also responsible for the amount of chlorophyl in the leaf and therefore the color or shade of green that you see. Yellow means low nitrogen/chlorophyl levels. Dark green means very high levels. This is why a properly flushed plant ready for harvest will have almost all leaves yellow and/or dead. Chlorophyl makes the bud taste bad. That's for later though I guess. For now you want neither yellow nor dark green but a happy medium green. Finally, is the burn aspect of nitrogen. This is very easy to do in veg but can still happen in flower. Starts with bright yellow or white leaf tips and is followed by bright orange rusty color spots on the intravascular leaf surface.

Phosphorous (P), unlike nitrogen, will not be absorbed in excess by the plant. It is virtually impossible to give the plant too much P especially in flower. The plant takes what it needs and the rest is washed out in the runoff with your next watering. Phosphorous is responsible for the sheen or shine of your leaves. A dull leaf with a matte finish could use more P. Leaves should be reflective and shiny like little solar panels. Other P def signs are large blackish/dark brown patches on the leaf surface or stems that are dark red or purple in color.

Potassium (K) is important for cell growth and formation. Like Phosphorous it is very hard to give too much as the plant will take only what it needs from the medium. Potassium is needed for strong stems and branches. K def will affect the leaf margins causing yellowing and/or graying and death to the tissue and subsequent deformation of leaf shape.

So moral of the story is you want as much P and K as you can get and moderate your N levels very carefully to achieve neither deficiency nor excess (until the very end at least when you want severe deficiency to ensure there is no chemical nutrient left). So that's about the best I can tell you. Keep all these things in mind as you go forward and try to find the balance which makes that plant happy.

-/\/\ared

 

[dtownscience]

Thank you very much Mared, some great info.
You are right they are early in flower. I was comparing them to my other strain that I have growing, which is Afghan Kush Ryder. I realize that normally this would not be a valid comparison, but from what I have read, the AKR takes much longer to flower, so it was unsettling that the AKRs were further along.
I really like your solution about using a separate mixture for P and K, that is smart.

By the way, for anyone else reading along, everything Mared has said here correlates exactly to what I've read (around), as well as what my private consultant friend has said.

Here are the plants 5 days later, after some flushing (3:1 water to soil) and a little molasses because I like molasses:

I have decided to stay with light feedings for these plants (after I resume feeding, that is) in order to keep them from becoming deficient in P/K. I have noticed the darkness of the leaves fading, which is good.