Yellowing leaves on landrace sativa

[RenaissanceBrah]

Anyone know what might be wrong with my Zacatecas x Michoacan from SnowHigh? Or is it just normal yellowing in flower?

Looks like it has 6 weeks or so left of flower. It did have some stress from not being watered enough lately.

Growing in super soil from Mountainside Organicos, under 4000K Kingbrite LEDs, 7 gallon aerated pots, RH is about 60%, about 26C (78F), watering with RO purified water. Haven't fed anything, just have let the super soil provide nutrients.

(Posted a similar problem recently, but this is in a bigger pot, and different genetics, not sure if it's having the same problem)

 

[Creeperpark]

Your plants are hungry and giving up the older leaves to transfer the mobile nutrients to where they are needed most. When you let the soil dry out you may have caused the yellow leaves. If you water with a low enough pH, the acidic pH will allow hydrogen to exchange with more useable nutrients. I do pour throughs and catch the run-off and test EC for this very reason. If one tests the run-off from the beginning to the end of the grow to monitor electric conductivity one can tell when the cation nutrients get low...

 

[StickyBandit]

Nice looking strain
If it's not had a feed since the start I would guess it's getting hungry

 

[49th]

Yeah looks like a pretty decent sized plant in a smaller container with nothing other than the soil mix? Give it some light feeding assuming it has a long time to go. It is okay to give nitrogen to flowering plants, just don't overdo it.

I see this pretty often since I don't use much else other than watering and sometimes fish fertilizer when this happens. I did try a top dressing of milled malted barley and some mineralized phosphate this year though. Also, I sometimes give them a light top dress of insect frass and neem meal as part of the pest management protocol which seemed to give some N to the really big plants in relatively small containers I have going now outdoors.

 

[RenaissanceBrah]

Your plants are hungry and giving up the older leaves to transfer the mobile nutrients to where they are needed most. When you let the soil dry out you may have caused the yellow leaves. If you water with a low enough pH, the acidic pH will allow hydrogen to exchange with more useable nutrients. I do pour throughs and catch the run-off and test EC for this very reason. If one tests the run-off from the beginning to the end of the grow to monitor electric conductivity one can tell when the cation nutrients get low...

Thanks Park, is measuring EC difficult? I might invest in a EC monitor, haven't heard of doing that.

 

[RenaissanceBrah]

Yeah looks like a pretty decent sized plant in a smaller container with nothing other than the soil mix? Give it some light feeding assuming it has a long time to go. It is okay to give nitrogen to flowering plants, just don't overdo it.

I see this pretty often since I don't use much else other than watering and sometimes fish fertilizer when this happens. I did try a top dressing of milled malted barley and some mineralized phosphate this year though. Also, I sometimes give them a light top dress of insect frass and neem meal as part of the pest management protocol which seemed to give some N to the really big plants in relatively small containers I have going now outdoors.

Thanks - I think I have some fish fertilizer around. How much would you recommend using? These are 7 gallon pots

 

[49th]

Thanks - I think I have some fish fertilizer around. How much would you recommend using? These are 7 gallon pots

I'm of the train of thought that generally, it's good to look at whatever the recommended 'regular' suggestion it gives and cut that in half. You can always add more but can't take it out, right? It's a good mild all around fertilizer.

 

[StickyBandit]

Thanks - I think I have some fish fertilizer around. How much would you recommend using? These are 7 gallon pots

Do you have a truncheon? https://bluelab.com/new_zealand/bluelab-truncheon-nutrient-meter
or maybe there are some mixing instructions on the product?
One good watering at about CF 25 of fertilizer is probably enough so close to harvest. That shouldn't be too much of a good balanced nutrient

 

[PolyChucker]

I have played around with Alaskan fish fertilizer a lot lately and early on in veg it seems like you could give 2tbsp/gal with every watering (10-2-2) but that’s kinda pushing it and you’d have to read the leaf color over time. This is like 50x what it says on the bottle to give to tomatoes or something like that but I keep upping it slowly over time and haven’t seen any N burn. I usually give about 1-1.5tbsp/ gal (for around 5-1-1 to 7.5-1.5-1.5) in veg and water every day, enough so it’s not soggy in the morning or too dry.

For you I would say 5-1-1 (1tbsp/gal) seems very safe - make one gal and give a cup or two each watering.

I try to keep it simple with one veg (5-1-1) and one bloom (0-10-10) fertilizers commonly available but I read recently that ideal ratios are something like 3-1-1 for veg, 1-3-2 early flower and 0-3-3 late flower. I think next round I’ll try getting as close as I can to that using my 5-1-1 and 0-10-10 veg and bloom ferts. I came up with this
Veg: 2tbsp fish, 2.25ml bloom ->10-3.5-3.5
early flower: 9ml fish, 1tbsp bloom ->3-10-10
late flower 1tbsp bloom -> 0-10-10

Even trying to keep it simple it still gets complicated!
this is for neutral potting soil. Seems hard to figure out how to deal with a rich soil