Need some advice

Hi all,

This is my first grow and I have been trying to keep it all very simple. I've got two plants indoors in a tent, both autoflower, one is a Royal Jack and the other is a Northern Light, both from Royal Queen Seeds. I am using a soil that is fertilized (Compo Sana Blumenerde) which a lot of people use here in Europe. As far as watering goes I've always saturated the soil with PH 6.5 and waited until the soil is totally dry until the next watering. On day 57 after germination I noticed some yellowing with brownish spots on the Northern Light. I checked the PH value of the runoff and found it to be very low, so the next watering I raised the PH to around 7.5. After several day when things didn't get any better I did a complete flush of both plants with a PH value of 7, this was 3 days ago on day 61 after germination. I think my problem is that I didn't do enough runoff during each watering causing a built up of salts in the soil which led to a nutrient block of some sort. The pictures show the Royal Jack on the left of the tent and the Northern Light on the right. I did notice some very small spots on the Royal Jack but it looks very healthy compared to the Northern Light and they were both raised under the exact same conditions. I think the harvest should be in the next couple of weeks, would be very appreciative of any advice of what to do or not to do until then.

Thanks for any advice

With only a couple weeks left, not much you can do. Your thoughts on lack of run off sound right. You want to aim for around 20% to keep the salts moving and the microbes happy. Congrats on getting thru your first. Do your homework on dry/cure. Don't want to waste all the effort!

Thanks Jypsy Dog, is there any chance that the buds can be damaged in the next couple of weeks (should I harvest earlier)? I've also been doing my homework on drying and curing and have everything ready, I really can't wait, the smells coming off these plants are phenomenal.

hanfman said:

Thanks Jypsy Dog, is there any chance that the buds can be damaged in the next couple of weeks (should I harvest earlier)? I've also been doing my homework on drying and curing and have everything ready, I really can't wait, the smells coming off these plants are phenomenal.

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Just keep the humidity as low as you can till finish. Do you have a Loupe to view the trichomes?

Were you feeding it at all, or only counting on the fertilizer that came in the soil? The slow release fertilizer is not recommended to grow marijuana. The spots on the leaf in one pic looks to be manganese or a calcium deficiency. At day 60 with an autoflower, it's pointless to tend to as the plant is done within 2 weeks anyway.

Jypsy Dog said:

Just keep the humidity as low as you can till finish. Do you have a Loupe to view the trichomes?

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Yes I have a Loupe, one thing that has me confused is the development of the buds on different parts of the Northern LIght, some of the buds seem more ripe than the others.

Blitz35 said:

Were you feeding it at all, or only counting on the fertilizer that came in the soil? The slow release fertilizer is not recommended to grow marijuana. The spots on the leaf in one pic looks to be manganese or a calcium deficiency. At day 60 with an autoflower, it's pointless to tend to as the plant is done within 2 weeks anyway.

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I was counting on the fertilizer and everything worked great until week 9. I think it is strange that the Royal Jack on the left is doing so much better than the Northern Light on the right given that they were grown under the exact same conditions.

hanfman said:

Yes I have a Loupe, one thing that has me confused is the development of the buds on different parts of the Northern LIght, some of the buds seem more ripe than the others.

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You can always do a "Selective Harvest," I have done it several times with a strain that has Patchy finishing. Once you see what your aiming for... Take it. Adjust the lights or plant and grow on.

hanfman said:

I was counting on the fertilizer and everything worked great until week 9. I think it is strange that the Royal Jack on the left is doing so much better than the Northern Light on the right given that they were grown under the exact same conditions.

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Like teenagers, they eat at different rates. The Northern finished her plate first.

Jypsy Dog said:

You can always do a "Selective Harvest," I have done it several times with a strain that has Patchy finishing. Once you see what your aiming for... Take it. Adjust the lights or plant and grow on.

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I have read about and thought about doing a "Selective Harvest". Would cutting off some buds earlier hurt the plant? Is there any special procedure while doing a selective harvest?

Jypsy Dog said:

Like teenagers, they eat at different rates. The Northern finished her plate first.

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Do you think I should give some extra nutrients in the next couple of weeks? I bought some CANNA Terra Flores (N-P-K 2–2-4) in case I needed it in the flowering stage. Right now I am a bit scared of over or under doing anything.

hanfman said:

Do you think I should give some extra nutrients in the next couple of weeks? I bought some CANNA Terra Flores (N-P-K 2–2-4) in case I needed it in the flowering stage. Right now I am a bit scared of over or under doing anything.

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If u only have two weeks left till harvest I would start flushing with water not add nutrients

What you put into your plant is more important than what comes out as runoff.You should never feed at 7.5,that's not how it's done.

jonathan17 said:

If u only have two weeks left till harvest I would start flushing with water not add nutrients

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Thanks, I think I'll keep it simple and stick with water.

nmibud said:

What you put into your plant is more important than what comes out as runoff.You should never feed at 7.5,that's not how it's done.

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I've always watered with 6.5 and when I checked the runoff it was usually around 5.5, when I saw the yellowing I checked the runoff again and it was close to 4. That is why I watered with 7.5, I thought it would raise the PH of the soil to a decent level. I realized that it was not the best decision, that's why I did the flush, am watering now with 6.5.

I am blessed with well water at 6.4 , after nutes and cal-mag it's 6.2. works perfect for the hempy buckets.

hanfman said:

Do you think I should give some extra nutrients in the next couple of weeks? I bought some CANNA Terra Flores (N-P-K 2–2-4) in case I needed it in the flowering stage. Right now I am a bit scared of over or under doing anything.

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If your going to harvest over time, sure. Don't be surprised if those plants go 3 more weeks. Plants can't read a calendar. Don't need to flush with soil. Relax and give them a 1/2 strength feeding and let them finish up. You have no tip burn, the issue with the yellowing is on lower/older growth. When I harvest in stages, it's usually the tops that come off first. I just adjust the lights or the plant to get better coverage to the buds to help ripen them up.

Jypsy Dog said:

If your going to harvest over time, sure. Don't be surprised if those plants go 3 more weeks. Plants can't read a calendar. Don't need to flush with soil.

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I think you might be right, but it's going to be really hard to wait another 3 weeks. The place I bought the seeds from says harvest is 9 to 10 weeks after planting, but I've heard people say that is only possible under perfect conditions.

hanfman said:

I was counting on the fertilizer and everything worked great until week 9. I think it is strange that the Royal Jack on the left is doing so much better than the Northern Light on the right given that they were grown under the exact same conditions.

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Plants from different strains and even different phenotypes within the same strain, will respond differently to feedings and conditions. I have 2 plants now, one is about 50% bigger than the other one, yet it's the smaller one that eats way more! The big one wants very very little! Put it this way, the bigger one, which is my biggest plant to date by far, is eating less than my auto's which are about a third of the size usually.

Blitz35 said:

Plants from different strains and even different phenotypes within the same strain, will respond differently to feedings and conditions. I have 2 plants now, one is about 50% bigger than the other one, yet it's the smaller one that eats way more! The big one wants very very little! Put it this way, the bigger one, which is my biggest plant to date by far, is eating less than my auto's which are about a third of the size usually.

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I understand that each plant strain has different needs, but such a huge difference seems strange to me, I added a small amount of nutrients to both of them this afternoon. The Northern Light which is the bigger one on the right uses much more water than the Royal Jack and is a much bigger plant, but I must say the main Cola on the Royal Jack is very impressive!