Tomato mini-plants and hardening off???

My first time growing indoors from seed is more of a success than I bargained for!!

I sowed more than I need, figuring a learning curve and a low success rate (11 plants needed, 12 seedlings culled and 30 mini-plants still growing. . . . and growing!!). My planned plant out date is May 1, almost another 3 weeks away.

These mini-plants are short (about 6") and stocky, since they've been going outside beginning when they had their first leaves and it was warm-ish, almost daily now-a-days. Today, they stayed outside for six hours. . . tomorrow (weather permitting) they're scheduled for 8 hours!!! By next Saturday, they're scheduled to stay outside from dawn to dusk.

But how cold is too cold to let them outside?? I read (on the 'Net) that anything above 40 is fine.
And how much BIGGER will these get in these last 3 weeks?? (According to the schedule, they're to be fertilized next watering.)

Pic was today. . .

BetNC - Good job! Those are some nice tomato seedlings.

By May 1 they'll be bigger than I raise seedlings to be, but they'll be OK. You've got them in what I think are the red plastic 16 oz. cups from WalMart that I used to raise seedlings in, so they've got plenty of soil and shouldn't get too rootbound. When you transplant them into your garden, they'll have more stem to bury in the ground - and that's a good thing because tomatoes grow roots from all of their stem that's in contact with soil.

I wouldn't give them any more fertilizer - you want as little growth as possible now, not more. It's good that you're hardening them off outside already, but watch the weather - don't let them get beat up by wind, rain, hail, or get nipped by frost. As you say, it's probably best to not have them out when it's less than 40 degrees, to allow a safety margin above the freezing point.

Cool temps retard growth, and that's what you want for the next 3 weeks. Maybe you have an unheated garage or shed where they can spend the nights cold, but not freezing. That would help a lot in keeping their size down.

dont feel bad, look at the monsters im having to deal with, lol, i was a bit too over eager with starting mine.

you can pot them up a couple of times and they will still be ok....as for the massive amount that you have....better check and see if any friends / neighbors will be interested.

Thanks for the advice Ozark! They've already been fertilized twice: once when they got their first true leaves and again a bit over a week ago, when I re-potted them from 8 oz coffee cups to these 18 oz Solo cup knockoffs. They DID have purplish stems and leaf undersides before but now just have purplish leaf undersides; I ripped off their little (yellowing) seed leaves and buried them up to their first two leaves!! I live in an apt. with no outside buildings but I DO turn the thermostat down nightly to 62 (I'm a hothouse variety who can't stand it any colder! LOL)

Heaven's to Betsy, jmc! PLEASE tell me your monsters aren't what mine will look like when they're 8 weeks old!! I need only 11 tomatoes and purposely grew out a spare just in case; I just COULDN'T discard ANY seedling (I had also sowed 6 flower species), but when I potted up to the coffee cups, I had more than my little gro station could handle. . . . so sadly but somewhat ruthlessly culled down ALL species to maximum capacity. The neighborhood grapevine is a-buzzing (somebody spotted my mini-trees taking in the sun and some have already come a=knocking LOL) plus I know a friend who goes to a Senior Center, so I will have NO trouble finding good homes for my excess - tomatoes AND/OR flowers!! hahaha

i started these guys back at the beginning of february, when i really should have started them at the beginning of march, i think. They are already trying to bloom on me, i have a feeling that i will be one of the first people around here to get actual garden produce this year--not that im bragging or anything, but thats just what the plants are doing, lol. I started them off under a bright florescent light bulb indoors, you know, those long tube shaped ones that are typically suspended above the plants. (although in my case i lacked such an ability to make such a set up, so i stacked the ends of the light on books, and added more books as the plants got taller)

jmc Now you done scared me! In another 3 weeks, I'll have monsters, too!! OH NO!! What WAS I thinking???

my DIY gro station is a simple frame of PVC pipe and a 4 ft heavy-duty 4 bulb t8 shoplight ($49 @ Home Depot) on a simple, cheap timer(also Home Depot). Also four ft linear flourescent Daylight bulbs (K 4700? and 3750 lumens?) The shoplight was the most expensive item and the PVC pipe was the cheapest!

Here's the YouTube videos I followed (For uprights after two weeks you'll want/need longer PVC pieces and a reflective survival blanket to tape on the long horizontal pipe, making an lean-to structure -Walmart camping section, $1-2). Come to think of it, you prolly already have/use some type of light-reflecting thing for your monsters!!! hahaha

https://www.youtube.com/watch?v=ifimJYiPw50
https://www.youtube.com/watch?v=9rqbrbcU3WI

Here's some pics of mine in use the first few weeks or so (each set=up easily accomadates 2 1020 flats-horizontal to the shoplight- for initial germination and new seedlings, with a max capacity of 5 1020 flats of potted-up seedlings in 8-oz coffee cups-20 per flat-, perpindicular to the shopplight. . .

ps: my 30 tomato mini-plants in 18 oz "Solo cups" take up 2 1020 flats!

oh i also forgot to note that once they got a few leaves, i added earth worm castings to their growing mix, i started feeding them with that at such a young age because its so gentle on them compared to any commercially made liquid / granular fertilizers. I think thats one thing that helped to rocket them up so fast

purple stems and purple leaves on the under side are an indication that your Seedling babies may have been too cold and too wet at the same time. It's what the seedlings do when they experience both of those conditions together.

Think "blue babies", without the heart condition.

It's also a sign of low magnesium (I think) I know it's some element but Im not sure which one. Lol The purple coloration usually corrects itself once the plants are in ground,

your ALL right about the purpling!!! Yep, it's a reaction to cold temps. . yep, it's a deficiency of Magnesium. . .yep, they grow out of it once they're in the ground (it;s both warmer temps and there;s magnesium in them thar hills!,

so far, nobody's mentioned another possible reason: they're not getting enough food / they need to be fertilized.

I guess y'all can tell that when I first saw purple, I panicked. . another website devoted to tomatoes calmed my nerves, so I'm rather blase about my purple "babies" now! LOL

i did go ahead and put the giants that i had into my garden bed, along with everything else. you can probably do the same now, seeing as youre in the same growing zone as i am in :)

all of that extra space is where i am waiting for flower seed / rootstock to start coming up, and a lot of it IS sprouting up, just cant see it too well in this shot. :)

This message was edited Apr 14, 2015 1:05 PM