seeds Seed Starting

So I'm getting ready to do my first grow from seed. I've done tons of research, but have a few basic questions left. I have a 250W metal halide with an internal ballast. I plan on starting seeds about 2.5-3 months before my projected plant out date. They'll be potted up indoors up to 6" pots, and will be started in a potting mix with a good amount of nutes in it. No additional ferts other than some epsom salt will be used unless I see a deficiency. Here are my questions...
 
1)How many plants could be grown under this light until plant out? I don't want leggy plants, but need to fit as many plants in as possible. I'm not sure if the 3000 lumens/square foot rule applies to giving your outdoor plants a head start.
 
2)About how big should my plywood grow box be for that number of plants? (L X W X H)
 
3)Is it possible to grow superhots in Vegas? I've been reading posts where people were having a hard time getting any pods in similar weather. It gets over 100 almost every day in the summer, with extreme dryness.
 
Thanks for all your help!!

If you are only growing them inside for 2.5 to 3 months then a 6 inch pot may be a little big. It won't hurt them to be in a pot that big but it will take up a lot more room.

Ocho Cinco said:

If you are only growing them inside for 2.5 to 3 months then a 6 inch pot may be a little big. It won't hurt them to be in a pot that big but it will take up a lot more room.

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What size pot would you recommend? As you can probably tell, I have no idea how fast these plants grow in their early stages. I was thinking I would need about a square foot of grow box space per plant so the canopy didn't overlap too much and make it hard for the light to penetrate. I'm going to have to find the time to check out some more glogs...

The Bigger the pot the better, IMO, More root space the faster they will grow in the long run, as a friend said, "more roots, more fruit"  Bonsai doesn't grow fast as they have no root space to grow.   If I could start all my plants in 1 gal pots or bigger and veg 2.5 to 3 months under lights they would be so much bigger then the 4" I most times start my plants in.  

To answer your question, I would think 36 plants is about all you can realistically expect for a 250 watt bulb. That would be an area around 3' x3' with 6" pots. At 3 months, they won't be all that huge yet so you can keep them pretty close together.

Even that is pushing it a little since you are only delivering 2500 l/sq.ft, but it should be fine for plants only 3 months old.

I have 300 plants 4 weeks old in 4 inch containers under a 1000 watt with another 800 on the other side of my basement with 2 more 1000 watts so you should be fine with 30-40 under a 250

HotPursuit said:

What size pot would you recommend? As you can probably tell, I have no idea how fast these plants grow in their early stages. I was thinking I would need about a square foot of grow box space per plant so the canopy didn't overlap too much and make it hard for the light to penetrate. I'm going to have to find the time to check out some more glogs...

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LOL... you probably saw my glog. I can tell you that now would be a good time to sow. Here's from my experience.

I started in January, and my plants started flowering late April and mid May, but then it got too hot for flowers to set and then when the heat came in my plants suffered... most died others I gave away and some few I kept, but nothing much happened when the temps get above 100ºF+ (no growth).

Sooo.... if I started about a month earlier I would have some flowers set and maybe had pods before the heat wave. Some of the plants started growing nice when the weather cooled down, but they were still too small and didn't produce. I did have a mature Sonoran tepin that had lots of flowers and gave a few pods.

If I were you, I'd start now. If your plants get to large you can always cut them back to your likes and space.

We should meet up sometime and talk about it and I can give you seed for whatever you want to try. Just lmk .

-Walt

Got 72 in 3.5" squares-under a 6 tube x4' T5HO--3 months would have been about right---pushed them to 4 though.
Don't load the sprouts with nutes---they will burn.
Don't forget the fan to make them strong.
 
Don't know the best time for Vegas.
I might consider starting them indoors in June and let them develop in nice air conditioning through the summer, putting them out in late August.
 
A bit north of you, and the July temps over 100 really shut them down to survival mode.

Thanks everyone for your responses. I'm starting to get a better idea of what to do.
 

Vegas_Chili said:

LOL... you probably saw my glog. I can tell you that now would be a good time to sow. Here's from my experience.

I started in January, and my plants started flowering late April and mid May, but then it got too hot for flowers to set and then when the heat came in my plants suffered... most died others I gave away and some few I kept, but nothing much happened when the temps get above 100ºF+ (no growth).

Sooo.... if I started about a month earlier I would have some flowers set and maybe had pods before the heat wave. Some of the plants started growing nice when the weather cooled down, but they were still too small and didn't produce. I did have a mature Sonoran tepin that had lots of flowers and gave a few pods.

If I were you, I'd start now. If your plants get to large you can always cut them back to your likes and space.

We should meet up sometime and talk about it and I can give you seed for whatever you want to try. Just lmk .

-Walt

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It's a bummer that your plants died, but I'll definitely learn from that. I think I'm just going to start them as soon as I can get the box built. I honestly didn't think about the heat killing them, I was more concerned about my yields 
 
I'm definitely planning on getting ahold of you some time soon. I'm thinking next week/weekend if that works for you.
 

Gotrox said:

Got 72 in 3.5" squares-under a 6 tube x4' T5HO--3 months would have been about right---pushed them to 4 though.
Don't load the sprouts with nutes---they will burn.
Don't forget the fan to make them strong.
 
Don't know the best time for Vegas.
I might consider starting them indoors in June and let them develop in nice air conditioning through the summer, putting them out in late August.
 
A bit north of you, and the July temps over 100 really shut them down to survival mode.

Click to expand...

I'm pretty set on getting these plants started over the winter, I'm not very patient. But I think I'll start a second set in June just in case I end up killing them. At worst, I'll have a few plants to give away. Thanks for the tip.
 
 
So I now know that my light will be more than enough for the number of plants I want to grow. I just need to figure out the dimensions of my box now. How much grow space should I allocate each plant if I start them 4 months before plant out? I know there can't be an accurate number and I can always trim the plants back. I'm just looking for an estimate. Also, about how tall should the box be, keeping in mind I will be using a metal halide. There doesn't seem to be much info about plant size online.