Leave edges turning lime green?

[RackitMan]

Babies are almost 3 weeks old and looking very healthy and bushy. They are in 50% seed-starter soil 50% Supersoil, watered every 2-3 days (very dry here) with spring water. No ferts yet.

Lights are 3 each 13 watt LEDs (red and blue) and 3 each 24 watts of cool and warm CFLs.

They are in 1 quart pots and are about 6" tall and about 6" wide.

Two fans provide cooling and fresh air.

The two slightly shorter ones have some very pale (lime green) edges on the leaves, but are getting enough light. I rotate them twice a day to get even lighting. No wilting or curling.

Is this 'normal'? Is it time to start fertilizing or what?

RackitMan Reviewed by RackitMan on 05-31-2008. Leave edges turning lime green? Babies are almost 3 weeks old and looking very healthy and bushy. They are in 50% seed-starter soil 50% Supersoil, watered every 2-3 days (very dry here) with spring water. No ferts yet. Lights are 3 each 13 watt LEDs (red and blue) and 3 each 24 watts of cool and warm CFLs. They are in 1 quart pots and are about 6" tall and about 6" wide. Two fans provide cooling and fresh air. The two slightly shorter ones have some very pale (lime green) edges on the leaves, but are getting Rating: 5

[wayward]

It sounds like it's time to fertilize. In one quart containers, I'd consider giving them a quarter teaspoon of a fert like Peters 20-20-20 mixed. in a gallon of water. If you have a tds meter, add fert to a gallon of water until the number is about 750. Perhaps fertilized every other time you water, or every third time. That kind of thing. I'd consider putting each plant in its own 5 gallon bucket with a cup of Whitney Farms powder fert mixed in, or something like it, like Foxfarm powder which I think is 4-8-7.

[stinkyattic]

You'll want to use a nutrient that has a ratio of about 5-2-3 or so for a plant in the vegetative stage. 'Even' ferts won't provide enough nitrogen relative to other components for a rapidly growing annual indoors. Start half what the bottle says and work up.
Post pics if you get a chance; yellowing low leaves can also indicate insufficient light, but have a different 'look' to them than N starved ones.

[wayward]

I'm sorry Stinky but I have to disagree with this: "'Even' ferts won't provide enough nitrogen relative to other components for a rapidly growing annual indoors."

The plant, in my opinion, will be fine. The manufacturer wouldn't go through the trouble to make the fert even if it didn't work. It does work. The more important issue is one of time. Powdered ferts that don't dissolve readily in water can require alot of time to break down. Bacteria does the work to break things down in soil. Anyone that has used bone or blood meal indoors has learned this one the hard way. Besides, if you use a low P-K kind of fert, you'll have to boost those in bloom.

[stinkyattic]

The manufacturer wouldn't go through the trouble to make the fert even if it didn't work.

What kind of logic is that? That's like saying you should put tractor tires on a dirt bike, because after all the fact that they were manufactured means they work. Work, yes; in context. Applicable to this context, no. The manufacturer made it for a specific purpose. Houseplant food is made for slow growing evergreen jungle foliage plants. They don't need NEARLY the amount of nitrogen that a vegging cannabis plant does.

Besides, if you use a low P-K kind of fert, you'll have to boost those in bloom.

That's why all serious cannabis growers use two different base ferts, one for flower and one for veg.

You can unscrew a metric bolt with a metric socket.
You can unscrew an English bolt with a socket measured in 16ths.

Or you can just say the hell with it and use a pair of Vise-Grips for both of them.

[wayward]

Well, this touches on a strange issue. Ferts have different NPK ratios. I've read that the reason for this is so people can tailor the fert to specific conditions. But my logic is also good, in my opinion. Using an even NPK fert can be and is just as good as anything else. My argument is this, a manufacturer wouldn't make a fert unless it works. An even fert is just as good as an uneven one. I believe that even NPK ratio ferts are better because they can be left alone for the life of the plant. I suspect that plants take up what they need when they need it. It is possible to overfert or underfert, however, the possibility is reduced in my opinion when an even fert is left alone. This has been my position on this issue all along - a grower really doesn't need to be too involved in the process, unless there's an obvious problem. Your words regarding the tires makes no sense. Do you honestly think there's as dramatic of a difference between ferts as there would be between bike and tractor tires? That doesn't make sense. You can use an uneven fert if you want; go ahead. But be prepared to spend more money and get involved in the grow more and also be prepared for more problems. Why do this when it can be easier. I wonder if there's anyone on this board that might be interested in giving my advice a test, just to see if they can prove me wrong. All it would take is one plant. Follow the recipe I gave earlier and see what happens. It works for me and it can work for other people too, without alot of expense and hassle. Try it, you might like it.

[Orzy]

Dude.. stop being such an ass. Honestly.

[stinkyattic]

I believe that even NPK ratio ferts are better because they can be left alone for the life of the plant. I suspect that plants take up what they need when they need it.

I believe, I suspect... okay. Horticulture isn't subjective.
As a matter of fact, you ARE correct that plants take up what they need, when they need it. And they leave behind what they don't use. It sits there salting up the soil and interacting with other fertilizer and soil components, and will need to be flushed out. Give them what they need, when they need it, in the correct ratios.

Do you honestly think there's as dramatic of a difference between ferts as there would be between bike and tractor tires?

Actually, no. I believe the difference is worse, because your bike won't run with tractor tires, and give you the opportunity to crash. You can crash with crap fertilizer before you even knew that what you were doing was wrong.