Is my oldest plant ready for flower ? And discoloration on young plant stem

Hey this is a follow up, my oldest girl which might be OG has been above surface since Feb 2 and took aawhile to kind of get this big which is roughly a ft. Since this is my.first grow im a newbie and Idk if my plant is or isn't ready to flower. I've switched the 18-6 to 12-12 for her going on about 3 days. I was wondering if maybe I'm flipping too early or it's the right time. And how should I be feeding her now seeing as tho I might change the schedule permanently if you guys think so. Also I've changed the humidity down to 55 ish since the change it used to range from 58-70 .
Now about the stems, they seem thick and healthy but my plant seems studded while the others are growing a bit faster, the short odd colored stems on this little lady aren't growing up or much wide. And I want a diagnosis on the rest of my plants. I've recently fed them and am going the route of feeding every other watering. I have them under 100% as of today under the 600W MH light. I would really appreciate some love and help.

I'm far from an expert, but everything looks good to me.

You can flip to 12/12 at any time really, but when the leaves start alternating, it's mature. Flipping before that can hurry things along, flipping later allows more growth before stretch, which can give a greater yield, but really it's up to you.

It looks like the leaves on the big plant are alternating, so now's a fine time to flip.

Regarding feeding, I generally use a rich organic soil and only topdress or give teas as needed. I'm sure someone more familiar with chem nutes will give you more specific advice, but it's my understanding that you'll want to taper off the nitrogen and push more phosphorous and potassium as you get through the stretch. As those look like heavy feeding WLDs, I wouldn't cut nitrogen out completely until you're close to finishing and flushing.

As far as a diagnosis, the one with the browning leaves looks like it was over fertilized or chewed on a while ago, but has come out if it just fine. The others look good to me. That one with the split middle leaflet is pretty cool.

There's a slim chance the purple stems are a result of phosphorus deficiency or cold temps (resulting in poor uptake of phosphorus), but considering all the other plants are healthy, I'm going to guess it's just a purple plant and will go even more purple in late flower.

If I'm wrong about anything, I'm sure someone else will chime in. Keep it up!

Your plant definitely looks ready to flower despite the short size. How far do you keep your plants from the light? Keeping them really close will significantly reduce stretching and result in much shorter and more compact growth. Try raising the light 8-12 inches. Plants can also respond to cold temperatures with shorter/bushier growth so be aware of that.

It's also possible you have a little too much magnesium going on. Although it's uncommon it will result in stunted growth and dark green foliage like we see with your plants.

Raise the light a bit mate

smokditup said:

Raise the light a bit mate

Click to expand...

How's this ?

Looks good mate. You can always raise it a touch more if they aren't stretching enough for ya.

Don't underestimate the flowering stretch, it can give many experienced growers a real headache. Slow vegetative growth could just be a stable phenotype in whatever cultivar your seeds came from, or it could be the result of cold temps, overwatering, shock from repotting, shock from pruning or topping, or some kind of nutrient lockout. In any case, they look pretty healthy now, so switching to a flowering regimen and gradually adjusting your macronutrients to reflect the needs of the plants moving through flowering is your next step. Don't worry about discoloration in the stems, just keep your temps above 65 and below 85 and you should be fine.