I posted a week ago with a problem with one of my plants. I found little black spots on her first set of leaves (but her other sets were fine). But now those black spots have turned into dry looking tan/yellow spots and the leaves are turning yellow. And now the second set of leaves is starting to get black spots. And another one of my plants is getting the black spots on her first set, too. Here's a picture of the early progression from a few days ago: http://imgur.com/YR0wl.jpg Here's what that same plant looks like now: imgur: the simple image sharer and here's my other plant thats starting to show the same symptoms: imgur: the simple image sharer Some more info: They're 3-4 weeks old, in red solo cups with ph-balanced no nute soil, under 3 cfls (2 6500k, 1 2700k) and watered only when they're almost bone dry. Someone please help me, I only have 6 plants, and if I lose 2 to whatever this is, it'll really hurt my harvest.. I think it may be a manganese or potassium deficiency but I have no idea how to remedy that.
You need to get an accurate way of checking your PH. Those dark brown spots look a lot like a deficiency, but it's a mistake trying to remedy anything without knowing your PH accurately.
Its around 7 on all of them. When I first noticed my PH was high (7.5-ish), I started watering them with a water+lemon juice solution. That has brought down their ph to around 7 and I'm gunna continue this until its around 6.5
Sly's right, my soil isn't acidic enough right now.. But anyways, does anyone have any idea what I could do to remedy this? Should I try spraying nutes on the leaves or something? (if so, what's a good nutrient supplement to buy?)
why not just flush with 3xVolume of container with 6.3 ph water buy PH down... after flush you will need a nute supplement because there will be no nutes left in soil.
Good idea, whats a good nute supplement to buy? or a good NKP ratio to look for, cause I'm probs gunna buy it from agway.
ff trio .. cost you about $45 for the set --> [ame]http://www.amazon.com/gp/product/B004JZGNCQ[/ame] EDIT: Only dosed twice at 1/4 strength so far but wow
Wish I could get that, but I'm broke atm and needed to get the nutes ASAP (can't really wait for shipping cause these black spots are spreading ). Instead I picked up some miracle gro all purpose that has 12-4-8 NPK from home depot. It also has Magnanese in it, which I think might help cause from the looks of it, its either a Manganese or Potassium deficiency based on this chart: I just bought this today and watered my plants yesterday, so I'm waiting till tomorrow to give them some 1/4 strength nutes. I did do some light foliar feeding today and the leaves all perked up. Do you think I'll be able to reverse the black/brown spots or are those gunna be there forever?
One more important point: The soil I'm using has no perlite/vermiculite in it.. its just the typical soil you find outdoors. Its got a kind of sandy texture which might help with aeration, but could the lack of perlite possibly be causing this too?
3-4 weeks in a tiny solo cup.... thats a long time . The rust spots are calcium deficiency ... You are learning the hard way why most people dont go dig up soil from outside to grow in.... Get some high quality potting soil with some added perlite for drainage , transplant into larger containers. And give them a light balanced feeding.
I'm transplanting them outdoors in about 6 days, where they'll be living in a mixture of perlite, MG organic choice and peat moss. The nute supplement I just started using doesn't contain calcium, tho. How can I get them the calcium they need?
Oh no... not Miracle Grow! Those plants are probably rootbound... and like someone said definitely calcium deficient. The spots are necrotic (dead) leaf tissue. That cannot be reversed. Botanicare's CalMag has calcium.
I had similar problems using Miracle Gro Organic Potting Soil. My best advice is too make sure your pH is in check, and get some better soil pronto! I bought Fox Farm's Ocean Forest, and after transplanting to that, the ride became much smoother. Check out the link in my signature to see my journal from then, and you'll see the progression and how I beat it. Hope that helps.