Possible rootbound? Plants yellowing.

[Dr. Fred]

My plants are around 3 weeks into flowering right now and I'm having some crazy yellowing. The only one that isn't is the one in a bigger pot.

They're planted in Canna Pro-Plus, for nutes in veg they just had Canna Bio Terra which I kept feeding until a week or two into flower. Now I'm giving them 30ml Bio Flores + 20ml Bio Boost per 10L water each time I water.

The one in a slightly bigger pot seems pretty healthy to me so I'm thinking that's the issue, any help or suggestions would be appreciated.

The pictures show 2 of the unhealthy looking plants and the healthiest looking one.

 

[Dr. Fred]

Oh yeah the strain is Seedsman WW, just some free seeds.

 

[Dr. Fred]

Overwatering or underfeeding is what I'm thinking right now. Keep searching around but it's only confusing me more

 

[frostqueen]

Overwatering or underfeeding is what I'm thinking right now. Keep searching around but it's only confusing me more

Hey Fred. Key question: how fast are they drying out? If the are rootbound they will dry out very fast usually. If they aren't... you may have some root issues. It's a good idea to let them mostly dry out (~80%) each time before watering again. Is that happening?

If they aren't drying out I'd definitely start using Hydroguard at 2 ml per gallon. That can help solve root issues. Let them mostly dry out as described for the best chance at recovery.

Not familiar with the soil, but one way to keep a base level of nitrogen going is to add in 10% earthworm castings. This gives you just enough so that most of it is used up by week 6 or so, and the microbes love it. A good compost would have a similar effect. Looking at the pics it seems like a straightforward nitrogen deficiency, an easy fix.

Nitrogen gets used very quickly, so by doing a one-time addition to the soil with BioVega or doing a foliar spray you can solve this easily. If you are having dry-out slowness I'd go the foliar spray route.

I've done the Canna bio line extensively. I'd definitely go with a full 15ml per gallon of the bloom, and a full 15 ml BioBoost per gallon throughout the bloom cycle. I know it seems expensive, but it will pay for itself 10 times over. Trust me on this; I did a lot of trials with it. That definitely isn't 'too much' food. My circle of people actually went further and did a PK boost using Roots Organics' HPK and HP2 during weeks 4-6.

If you want to give me some more details I'll pop back here tonight.

 

[Dr. Fred]

Hey, thanks for the reply.

They're drying out every couple of days, there has been a couple of times when I watered them even when not 80% dry. Usually I do make sure to let them dry out, I think I sometimes over-water and let the soil get too wet.

With the Vega would you mix it with the Flores or just use it alone? Also when you say a gallon is that a US or UK one? I don't mind using more even if it is expensive, I've just always been afraid of feeding too much.

Thanks again for taking the time to offer some help, I appreciate it.

 

[frostqueen]

Hey, thanks for the reply.

They're drying out every couple of days, there has been a couple of times when I watered them even when not 80% dry. Usually I do make sure to let them dry out, I think I sometimes over-water and let the soil get too wet.

With the Vega would you mix it with the Flores or just use it alone? Also when you say a gallon is that a US or UK one? I don't mind using more even if it is expensive, I've just always been afraid of feeding too much.

Thanks again for taking the time to offer some help, I appreciate it.

Hey again. Well, that's good news about the dry-out times. I usually lift the pots at watering to determine exactly how much liquid they need.

So I'd say you just have a basic N deficiency, probably from the underfeeding. How often are you feeding? I did feed-feed-compost tea and that seemed ideal. (If you don't do teas, feed-feed-water.) Also, maybe next time add some earthworm castings or compost to your soil and that should fix it in the future. Not a huge amount; 10% is good. You want it mostly depleted by week 6.

A few other things: yes, US gallons for the above amounts I gave. But this part is important: this only applies to the BioFlora, NOT the BioVega. BioVega amounts start at 5ml/gallon and max out at 8ml/gallon. Using 12 or 15ml of vega can impede growth, believe it or not. I had an email discussion with Canna and was told this. However, BioFlora can be safely used up to 20ml/gallon, which is their recommendation. I can verify this works well.

As an aside, people are really stuck on the concept of 'less is more' regarding feeding. To each their own, but as a 20-year veteran of growing with organics, chem, and hydro: no. The right amount is what you want, not less or more. Flowers aren't created out of thin air; they are dependent upon nutrients to gain mass and quality. Underfeeding is a common error; I guess people think they are saving money? The truth is that nutrient manufacturers like Canna have spent millions of dollars determining exactly what and how much to feed typical cannabis plants, so I'd trust their label instructions. I always start with label recommendations and then adjust from there after seeing results. Just a thought.

As for your immediate situation. I think you should go over to the organics subforum and ask folks about a good product you could use as a one-time foliar spray for a quick nitrogen boost. I don't think the BioVega is probably a good idea, as it doesn't really have huge amounts of N, and it has some other things in it that may impede flower development at this stage. I personally haven't ever done an organic N boost foliar spray before but I'm sure they exist.

I am chem/organic these days, so my solution would be a quick spray with pure crystalline N, which I get from RAW nutrients on Amazon. One foliar and you can see greening within hours; it's pretty amazing. I just assume that you want to stay organic only... those guys can help you with that.

PM me any time if you have further questions about the Canna line. Great stuff, I'm a big fan.

 

[Dr. Fred]

I decided to add a small amount of growing nutes and some epsom salts to their usual feed and I think they're looking a lot better.

Thanks for the great advice I really appreciate it.

Sorry pictures aren't that great but it gives an idea if you compare them to the last ones.