New Grower Mystery problems with my Day-20 plants -- any idea what this is?

[Archer]

This burn/erosion/wilting issues seems to be happening on all of my plants, interspersed at random among the leaves.

My first suspicion was nutrient burn. But the leaves are generally a fairly light green and are very soft. I'm growing the plants in a nutrient-rich soil and only did my first feeding (1 tsp Alaska Fish Emulsion per gallon of water) last Sunday.

My big fears are root rot (I have overwatered in the past, though I've long since stopped) or insects of some kind. Light or heat stress might also be an issue. These are growing outdoors on a balcony, and there's been an unusual heat wave in my city over the last week.

I only started noticing this issue today, and I check on my plants every day.

 

[420ing]

Sombody here will help you and the plant looks good apart from those small patches! Im a noob so i don't know whats up but im gonna keep an eye on the answers to this one from the experts here. How many plants do you have and what strain/s? Wish u good luck im sure they will be great and get over this! Peace!

 

[Archer]

How many plants do you have and what strain/s? Wish u good luck im sure they will be great and get over this! Peace!

Thanks. They are auto White Widows. Feminized seeds, so I'm hoping all four of my plants turn out to be girls. They haven't shown their sex yet, but I am expecting that as early as this upcoming week.

Concerned about the problem areas, though. These literally -just- showed up during the last few days. I am planning my second feeding tomorrow, and if this is nute burn, I'll hold off.

 

[skyhiggh]

Not sure but I feed alaska to my plants at about 2 or a little more tbs per gallon and never got any burn from it my plants are also outside I also feed biobizz grow like 2 or 3 ml per gallon and also no burn.. just my 2cents might not be burn.
Good luck

 

[Muddy]

The first thing to consider is a possible pH issue. Are you checking and adjusting the pH of your feeds and checking the pH of your run off, the water that runs out the bottom of the pot when you feed them? If your pH is out of range it can prevent the plant from up taking the nutrients and can lead to nutrient deficiencies. Also, tell more about your soil. Young auto plants can be adversely effected by soils that are to hot, ones that contain high level of nutrients. I don't see any perlite in that mix. Perlite is important for holding moisture and bring much needed oxygen to the roots.

 

[Archer]

I haven't ruled out a pH issue, and I am going to test the runoff and/or soil at my next opportunity. It seems like a reasonable working theory at this point.

I've known since the get-go that my starting soil is a little "hot" for young plants. The soil is a combination of a (very small part) OF and a (very large part) of Dr. Earth's 808 Homegrown mix. The latter mix contains perlite, worm castings, bat guano, fir bark fines, forest humus, peat moss, and a concentrated kelp extract. It also includes beneficial microbes and mycorrhizae.

The soil seems to retain moisture really well, in my experience. Maybe even a little too well. The top layer is still moist, sometimes, three or four days after a watering.

My guess at this point is that the soil's pH is too low, causing nutrient lockouts of some sort. If that's the case, what's an appropriate fix at this stage? I can't exactly dig up the plants, mix in dolomite lime, and repot. But would adding some lime to my next watering help? (Assuming the pH is indeed too low). Or should I just use a product like pH Up/Down in my waterings?

My tap water is fairly basic, btw: it tests around 9.1. Our water is quite soft, too. So I'm thinking about adding some Cal/Mag for feedings and waterings.

 

[Archer]

Fed and watered today with 1.5 tsp Alaska Fish Emulsion and 1 tsp Cal/Mag per gallon of water.

Runoff tested at 6.5 to 6.7 on my pH meter. I'll test again on the next watering, which won't have any nutes or chems added.

 

[Archer]

Plants seem perky today, after having been fed yesterday. Definite brown spots forming on many of the leaf tips, though. Resembles nute burn at a glance, but I'm still guessing it's a pH issue. Next time I water -- probably a few days from now -- I'll do a thorough testing of both the tap water going into the plants, and the runoff coming out of the plants. That should tell us more about a possible pH problem with the soil.

 

[Muddy]

What was the pH of the nutrient solution that you fed? Need to know that to compare to the run off readings.

I checked the web site on that soil and they say their target pH is 6.5. We've seen OF with the pH in the low 5s so that could be pushing it down a bit. I didn't see lime listed as one of the ingredients so I have to assume they don't add it to their mix. That would be the solution if the pH is low, mix some lime into the top layer of soil and water it in. Just know dolomite lime is slow acting so will take about 2 weeks before it become effective.

What you're seeing on the leaves could also be from the soil being so hot. If you plan on continuing to use it I would suggest you mix it with a soil less mix like Pro Mix or Sunshine #4. That mix would be good for growing photo sensitive plants. Autos generally only require about half the nutrients of photo plants.

 

[Archer]

Next time I water I'm taking a) tap water pH, b) tap water + nute pH, c) runoff pH. This will be a bit hard for me to do in the coming days, however, as my next nute feeding isn't scheduled until Sunday. I suppose I could whip up a batch just to test its pH, though.

The soil is probably low pH and probably nutrient-hot. I've heard that disturbing or repotting autos really stresses them out, though, and that many of them can't handle it. What would you recommend in terms of options that don't involve remixing the soil with another medium?