Hardening off issue

[bakerhardwoods]

I have screwed up a lot of seedlings, not just tomatoes, by having bad hardening off practices, and I'm going to do it better next year.


One problem will be resolved if I retire soon, which is that I'm not home during the day to put the seedlings out for just an hour or so to start.


The bigger problem is that it is difficult for me to get trays of plants on and off of my seedling cart. I have the cart in my dining room and it has three shelves that hold 4 flats each. Each shelf has 3, 4-foot shop lights. I keep the lights low with the tallest plants touching the light bulbs. I made a lip/edge around the outside of each shelf and the 4 flats are crowded up against each other. When I take the flats out, it usually does some damage to the seedlings and it is an unpleasant job. So, I do not want to take 12 flats out for an hour and then put them all back under the lights. It just seems like a process that is too complicated. I usually start with just a few flats of the cole crops and later other seedlings. Many of the plants, especially the sweet potatoes grow outside their area and get tangled up when I move the flats.



What I have been doing is put flats out on a partially shaded porch 24 hours a day, except when the temperature will be below 40 (and then I just put them anywhere inside for the night). That is too much time out all at once and I think I should move that up to 45 for tomatoes, peppers, eggplant, sweet potatoes, and okra.



I have to do something different, because I usually end up shocking the heck out of the whole lot of them. I don't have a basement, but i could move them in and out of the garage somewhat easily. However I do not have lights for them in the garage. I assume that if one puts them outside for one to a few hours, that they will need more light that that few hours (plus some indirect light in the garage) in a 24 hour period.


Do I need to bite the bullet and make another seedling cart with lights and more room to use in the garage to provide light when I bring them back inside? I do not relish this because of a lack of indoor space, and I like my car in the garage.



I've made cold frames a couple of times and tried just moving seedlings to the cold frame and not bringing them back inside. It is easy to get the cold frame too hot when I'm not home to open it. I've killed quite a few plants in cold frames.



Sorry for the long post. I'm struggling to find something that will work for me. Any thoughts would be greatly appreciated.

[slugworth]

LED grow lights,(the kind that hurt your eyes when you look at them) you can put the plants directly outdoors without the weaning process.
I swear by them and not at them.

[bakerhardwoods]

Originally Posted by slugworth

LED grow lights,(the kind that hurt your eyes when you look at them) you can put the plants directly outdoors without the weaning process.
I swear by them and not at them.

I have one of my shop lights converted to LED and could with some expense convert the others. However, aren't there other factors (wind, adapting to varying temperatures) in hardening off?


Thank you, Tim

[slugworth]

By the traditional planting time it is mostly the bleaching effect of sunlight.
If you are trying to plant early,ground temps are more of a factor than wind/air temps.
The traditional planting time in the ground here is memorial day weekend,but I cheat
and use 2 hole cement blocks stacked in a row.Warmed by an armored garden hose
snaked thru the holes pumping warm rain water 12v pump.June 17 I picked the 1st
red tomatoes.I missed last years record by 2 days.

[slugworth]

The led grow lights are a big help for people that don't have the time to babysit plants during the day.
I was looking at led lights the other day but didn't like the ratio of red to blue.
It was an 8 to 1 ratio of red to blue light,which is geared more towards flowers than starting
tomato seeds from scratch.I have 2 foot led lights with magnets glued to the back to stick
on anything metal.You could even stick them on old fluorescent light fixtures with the added magnets.
(recycled from old computer hard drives)

[slugworth]

2 years ago during the winter,indoor tomato plants were infested with whitefly.
I put them in an unheated porch but on food warming trays to keep the pots/roots warm.
Night temps went into the low 30's F and killed the pests without using harsh chemicals
and the plants were fine after that.
I brought them back in the house under lights for the rest of the episode.

[bakerhardwoods]

Thank you slugworth for the replies. My thinking is evolving. It is possible that my hardening off failures are related as much to leaving them on my shaded back stoop when it is too cold than just too much sun. Some of both, but when hardening off, if they have not been under LED lights and you put them out for just a couple of hours, they still need more light than that, right? I've been reluctant to bring them in to a place where they have little light, and I've just found it too much work to get them back under the lights. If I made some modifications to my seedling stand, that would be easier. Of course significant modifications themselves would not be easy.



I doubt if I will be shifting my other 8 two-bulb 4' shop lights to LED right away. I think I have a box of a dozen light bulbs for them that haven't been used yet too. i was planning to switch one at a time when the ballasts give out.


I do push early planting some, but haven't gotten ripe tomatoes in June since 2012. The so called frost free date here is May 10. I start planting tomatoes when the weather forecast is for lows of 45 or above through May 10, so that would be late April to early May. [This year, 2020, the forecast was wrong and I had a lot of tomato plants frozen to the ground.] I plant on raised beds, which are warmer than just a flat garden.

[zipcode]

From what I know UV is mostly responsible for that white burn on the leaves. So if those leds have enough UV or at least more intensity in the lower spectrum it could indeed help.