Potassium deficiency? Or heat stress? Or soil pH too high?

[Emeraldo]

If I had your problem I would Ph A bunch of straight water at 6.8 and run it through aka flush. Then next time for water use straight water Ph at 6.8 not flush but regular feed amount and check run off. The good part about using soil is time is on your side unlike hydro game would be over.If you have kelp this would be a good time to give them after done to help with the stress and high temps. Kelp is key for growing in high temps hint of the day.

CO, I used lots of kelp in mixing the soil. And I've been consistently giving the plants water pH'd to 6.8 during the early part of the grow in April to the end of June. Then heat wave came in mid-June, and I gave the plants lots of water during that period. At the beginning of July I put the grow on automatic watering and increased the amount. The tap water (automatic watering) pH is about 7.1, so not a big difference (unless the SLH has a particular need for 5.5).

So there is a bunch of stuff going on, and I am speculating about what the cause could be: a deficiency, maybe some of my amendments, soil pH maybe too high, but heat seems to be the culprit. If we assume the leaf damage is in fact from the heat in June, then it will solve itself over time. I still want to get to the bottom of what my soil pH is, still waiting on the meter to be delivered. Will post that when I find out. Thanks!

 

[FelipeBlu]

Highya Emeraldo!

Thanks for the video. Now, I LOVE SLH! But you may have noted that there is quite a lot of marketing hyperbole in the video lol. And there’s an obvious bias towards hydro.

Which brings me to the pH 5.5 that is constantly referenced. Since organic growers don’t worry about the pH of their soil, I can only assume that they are talking about the hydro pH - and that makes more sense anyway - since 5.5 is the low end of the typical range for hydro. And they always start off the updates with the hydro (until they weigh), so I believe the 5.5 pH is for hydro, not soil.

 

[Emeraldo]

Highya Emeraldo!

Thanks for the video. Now, I LOVE SLH! But you may have noted that there is quite a lot of marketing hyperbole in the video lol. And there’s an obvious bias towards hydro.

Which brings me to the pH 5.5 that is constantly referenced. Since organic growers don’t worry about the pH of their soil, I can only assume that they are talking about the hydro pH - and that makes more sense anyway - since 5.5 is the low end of the typical range for hydro. And they always start off the updates with the hydro (until they weigh), so I believe the 5.5 pH is for hydro, not soil.

I agree GHS are biased toward hydro. Just look at the size of the hydro plant next to the one in soil. The hydro is twice the size! Arjan and Franco are obviously presenting the hydro plant.

My mistake about the soil pH of 5.5. They don't distinguish between soil and hydro, and don't mention soil pH. I think you may be right about the 5.5 being hydro.

It's the same for Arjan's Strawberry Haze, just a general pH of 5.5. But I remember them mentioning at some point that soil pH would be 5.7. Anyway, they are recommending what actually caught me as a surprize, that low.

 

[FelipeBlu]

I agree GHS are biased toward hydro. Just look at the size of the hydro plant next to the one in soil. The hydro is twice the size!

But you must've missed the soil pH of 5.5. They mention it in each of the bi-weekly chapters, and 5.5 in soil is continually shown on the ribbon at the bottom of the screen. Hydro pH is mentioned separately @ 5.

I must have! However, in the bottom crawl, pH is always listed with EC, and I also heard them mentioned together in the audio. Since EC is a hydro-related term, I will maintain convinced that the 5.5 pH is referring to hydro also. Organic growers don’t care about EC, since they just use water or compost teas, and most pay little attention to pH.
I would have to advise you to not worry about it either.

 

[Emeraldo]

I must have! However, in the bottom crawl, pH is always listed with EC, and I also heard them mentioned together in the audio. Since EC is a hydro-related term, I will maintain convinced that the 5.5 pH is referring to hydro also. Organic growers don’t care about EC, since they just use water or compost teas, and most pay little attention to pH.
I would have to advise you to not worry about it either.

You are right. I went back an changed my response. They just say 5.5, I assume that's hydro. But soil wouldn't too much higher, maybe 5.7 is about right for these GHS strains.

 

[Emeraldo]

Anyway, I just tested the runoff and it is pH 6.0 after I pH'd the water to 6.0 today and gave them some. Assume that is the correct pH to remedy a K-deficiency, I will continue with that until next Wednesday, when my new pH meter arrives. I had been giving them water with pH 6.7 until now. Also worth noting, the heat damage occured a month ago and the wilting started a few weeks ago. Since then, no new brown leaf edges or yellow areas in the higher and newer growth.

Here a couple of photos showing the tops of SLH (left) and Acapulco Gold a few days ago.

IMG_1885.jpeg

• Emeraldo
• Jul 11, 2020

Somewhere there's heaven, how high the moon...

IMG_1884.jpeg

• Emeraldo
• Jul 11, 2020

Blue moon, I saw you standing alone....

 

[FelipeBlu]

Sweet! Over the roof!

 

[Emeraldo]

I wanted to mention that Greenhouse Seeds has changed their growing tips in the video since last year. I distincly remember them giving a soil pH recommendation of 5.7 or so when researching that last summer. But now it's not there anymore. I did find the older recommendation for Strawberry Haze in kindgreenbuds.com, quoted with link below. Unfortunately, kindgreenbuds doesn't give that info for Super Lemon Haze, but no matter, it's probably about the same. Arjan's Strawberry Haze turned out very well using water pH'd to 5.7 in soil. Apparently it does better in soil, while SLH does better in hydro.

Strawberry Haze performs best and delivers the utmost in strawberry flavor when grown in soil. Hydro systems can be used to increase the yield, but the taste is less sweet. Green House recommends a light hand when it comes to nutrients, as this plant is more sensitive to overfeeding than most sativas. Start with a low pH (5.6 hydro / 5.8 soil) and slowly increase to reach 6.5 at the end of flowering. Extra P and K should be added after the 5th week of flowering. The maximum EC should be 1.9 in hydro and 1.7 in soil. Flush plants at the end of flowering, which takes about 10-11 weeks or until mid-October outside.

https://www.kindgreenbuds.com/marijuana-strains/arjans-strawberry-haze/

 

[Emeraldo]

Sweet! Over the roof!

Thanks!

I call that somewhere over the raingutter!

 

[FelipeBlu]

Good one!

Okay, I’m gonna have to admit to ignorance on this method of growing in organic soil. I’m just not sure many organic growers, myself included (just not in pots), would know how to gradually increase the pH of their soil from 5.8 to 6.5 by the end of the grow, with a maximum 1.7 EC. Although some doing cationic drenches during flowering may be attempting to do just that. I’m just an old composter when it comes to the plants in outdoor beds.

 

[Emeraldo]

GHS recommends flushing at about week 5 and letting it dry out for at least a week. What I did after that was raise the pH of the water from 5.7 and slowly getting it up to 6.5 or so towards the end. Arjan's Strawberry Haze is a wonderful strain I would grow again.

 

[FelipeBlu]

It sounds tasty. I like most Hazes - mostly lemon these days - but strawberry might be nice for a change. Is it sweet?

When you raised the pH of your water, how do you know if it raised the pH if the soil?

 

[Emeraldo]

The GHS Arjan's Strawberry Haze (ASH) has a very berry aroma, yes there is sweetness. It is a truly good cerebral energetic social high with a bit of body.

To your question about raising pH: I grow in soil outdoors and mix up my soil from scratch, using among other amendments dolomite lime in an amount that keeps the pH stable, around 7.0. The way I grew ASH -- maybe it was just my interpretation of the GHS grow session video -- I simply pH'd the water to 5.7 for most of the grow, then in the last month of flowering I loosened up and gave them water that was around 6.3 to 6.7. Have a look at my 2019 grow "Arjan's Haze #1". Link below. I grew two ASH in that same grow.

Cheers

 

[FelipeBlu]

With soil by itself at pH 7.0 and if the water was 5.5, I figured the plants would get an overall environment of around 6.0.

I don’t think this is how it works. Have you heard of a slurry test to test the pH of soil? You will need a real pH pen - the soil pH meters (with the two long prongs) are not accurate.

 

[FelipeBlu]

Hiya Emeraldo!

Great journal for the Arjan Haze and ASH! One thing I noted, as a follow up to my last post -

Since my soil pH was above the prescribed 5.7 (the dolomite lime I added to the soil probably raised soil pH to around 6.8), I pH-adjusted the water to around 5.2 to compensate.

If your soil pH ends up around 6.8 due to the DL (I’m not sure how you determined this), it will tend to stay there (the buffering point) until all of the DL has been reacted by H+ (exuded from the plant or by the addition of low pH water by you). The simple addition of 5.2 pH water will not adjust the soil pH to something between after each watering.

I continue to maintain that a soil pH below 6 is not typically recommended, according to these graphics

 

[Emeraldo]

I don’t think this is how it works. Have you heard of a slurry test to test the pH of soil? You will need a real pH pen - the soil pH meters (with the two long prongs) are not accurate.

The quote from me in your post is, I guess, taken from the Arjan's Haze #1 grow. I have to correct that statement. I didn't have soil with pH of 7 and then just add water at 5.7. Actually what I did in May 2019 for that grow was mix from scratch a soil using a "forest floor" organic soil product (made 100% of ground wood fiber and composted bark) that stated on the package it was intended for growing berries and having a pH of 5.8. This gave me a starting soil with a lower pH than other available soils, much closer to GHS' recommendation of 5.7. And yes, I did a slurry test as well as a test of the runoff to satisfy myself. I pH's her water to 5.7 for most of the grow, then loosened up. There was DL in the mix as well, and when I used a soil pH meter towards the end of the season, in August, to test it and it at that point came out around 7.0 due to the dolomite lime's effect over time. Turned out well.

Obviously, haha, I am not too finnicky about soil pH, and if the plants are happy I don't fix it if it ain't broke. But when I see a problem pointing to a deficiency of some kind, I get busy trying to figure it out. This year I'm growing the Super Lemon Haze by GHS in soil that is probably around 7.0 (but I don't know this yet), and have been giving her water at around 7.1 for most of this season. Despite the GHS tip to grow her in 5.5 soil, she has grown mightily. Now the heat wave has stressed the plant and it looks like K-deficiency, but not only the SLH (other plants too have some leaf damage), and it's probably not all due to soil pH being too high, the heat gets my vote as the dominant cause of the leaf damage.

So the soil pH meters with the two prongs are NOT accurate? This is the one I ordered, do you think it will be accurate?

Gain Express Soil Ph & Moisture Meter 295mm Long Electrode

 

[FelipeBlu]

Yes, that quote was from the previous grow - thanks for the clarifying info.

You got it - reading your plants is what it’s all about! If they look happy...

Your guess is as good as mine re the accuracy of that pH probe - it certainly costs a lot more than the typical cheapy ones I’ve seen/used in the past!

 

[Emeraldo]

...To your question about raising pH: I grow in soil outdoors and mix up my soil from scratch, using among other amendments dolomite lime in an amount that keeps the pH stable, around 7.0. The way I grew ASH -- maybe it was just my interpretation of the GHS grow session video -- I simply pH'd the water to 5.7 for most of the grow, then in the last month of flowering I loosened up and gave them water that was around 6.3 to 6.7. Have a look at my 2019 grow "Arjan's Haze #1". Link below. I grew two ASH in that same grow.

The above isn't quite so. I forgot that I started out with the berry soil at 5.8. The other points are valid.

 

[Emeraldo]

Yes, that quote was from the previous grow - thanks for the clarifying info.

You got it - reading your plants is what it’s all about! If they look happy...

Your guess is as good as mine re the accuracy of that pH probe - it certainly costs a lot more than the typical cheapy ones I’ve seen/used in the past!

Yes, I've had many of those cheap ones, which also work. This is the first time I'm shelling out $$ like that for one. I guess I was panicking about the mysterious leaf damage and don't trust the cheap on I currently have. Thanks for all your comments and input, Filipe!

 

[Ghost Farmer]

I personally have never had to ph my soil up or down, it’s a waste of time because soil naturally buffers ph which leads to you always chasing some magical number. I would concentrate on nute levels, environmental conditions, and any pest issues since you are outside.