Do I need to harden off if they're going into a WOW? I will put the WOWs out a few days before I put the plants in so the soil gets warmer.

I start my seedlings under lights but put them outside during the day, when they get their true leaves and the weather is warm enough. I find a spot where they will get mostly shade and a little sun and will move them inside under the lamps at night. Eventually, I leave them outside at night as well. Before I plant in the garden, I will leave them in a sunny spot with one of those black mesh trays you get at the garden center, positioned so they are somewhat shaded from the strongest afternoon sun. I plant in the evening so they get a rest before direct sun hits and make sure the soil around the plant has some sort of mulch to keep the soil cool and moist. This works okay but I'm sure there are better ways. I work and my garden is not at my home so I cannot move my seedlings around into and out of the sun for a week like is recommended in a lot of information I read. I start tomatoes and melons this way, everything else I purchase from the garden center which I assume has already hardened off their plants. Right now, my tomato seedlings have been outside for the last 3 days and nights and are growing well. I potted them up last weekend and they need a lot more room then I have under the lights, I'm hoping the weather will stay on this warming trend since I need the area with the lamps to start the melons....

Do I need to harden off if they're going into a WOW?

Yes you do. Anytime there will be a marked change in the plant's environment they need to be gradually adjusted to it.

I have posted details on my hardening off process in the many previous discussions here of this topic so will pass on doing it yet again.

Dave

Thanks Dave.
There has been a lot of discussions in the past. Almost every season the subject comes up at least once.
My intention was/is to get a live interactive discussion, to make it more interesting , in a forum format.

here is a hint:
Try to choose a day with overcast skies/ partly cloudy day ,the first day or two. Or find a spot under tree shade with defused light.

I am going to do just that today. High ~~60F >>> Low tonight 48F.

Seysonn

Lucky you. It's still low 40s for highs here and snow flurries forecast for tonight. Not to mention 6" of rain in the last 4 days. The ground is nothing but hog wallows with onions and garlic growing in it. But I do have about 400+ inch and a half tall tomato seedlings with their first true leaves just popping out in the greenhouse so it will be another month before even think about hardening off.

Dave

Probably about another month for me as well before the hardening off process begins.

For me, it starts by removing the plants from under the lights and lining the trays up on the kitchen floor in front of three panel sliding glass doors facing south-southwest. I gradually expose them to sunlight by adjusting the vertical blinds in front of the doors so they get a bit more sun exposure each day. This, of course is determined on a day to day basis - the vertical blinds are open entirely on cloudy or mostly cloudy days. A small oscillating fan provides simulated breeze.

After about five days, they go out on the deck where they'll stay until planting day. At that point, they would only come back in the house in the event of an extremely cold night or, more likely, during a severe thunderstorm or tornado watch. Hail or 60mph wind gusts is not good for the hardening off process. After another five days on the deck, they should be ready to be planted, however this isn't exact. Excessive rain may delay this until the ground can dry up a bit and I can get them planted.

Immediately after planting, they get a good dose of deer spray or get covered loosely with deer fence panels. Several years ago after planting out the tomatoes, in less than 12 hours, the deer got to them. I was quite devastated. Fortunately, their roots hadn't yet anchored them into the ground, so instead of biting off most of the plant tops, the deer only managed to pull them out of the ground and left them there. I was able to replant most of them, but a few were goners and that was the one year I actually had to go out and purchase a few replacement plants. Now I make sure I have several extras on stand-by in the event of a similar catastrophe.

Another year after planting, unexpected torrential rainfall arrived overnight and all the plants were nearly completely submerged under standing water the next morning. That too was devastating, but amazingly, they all survived this.

So, hardening off isn't a terribly difficult or complicated process. For me, its about a 10 day duration. However, if I had as many plants as Dave has, I'd need a much bigger kitchen floor.

Thanks nitsua,
You have quite an elaborate hardening off and plant out procedure. Thanks for sharing.
In my situation, is just the possibility of unexpected cold, not even a frost, no deers, no high winds, no flooding, . We have PACIFIC weather here. But I know how it is in the mid west. I have lived in Joplin, MO

Seysonn

Because I grew seed for the first time this year...I paid close attention to the hardening off process. It paid off. Cold temps have not been a problem here since mid Feb (sorry). After keeping my babies under lights (16 hours on-8 off) for about 3 weeks...I started moving them outside. First few days for 1-2 hours. Picking days that did not have intense sunlight was a consideration. Sey's idea of picking a cloudy day is good. Gradually increasing the sunlight over about 8-12 days did the trick. I did have some slight "burn" on one cucumber plant. The sun was definitely too intense that particular day.

I have hoop house- walk in one, plants go there at about second week of April, when day temps are 50, at night they might get covered with blankets/ plastic or come in if it really cold night. They get planted into WOW at the end of April. I do take them out of greenhouse on calm day couple of times but that is extend of my hardening off process. WOW does the rest.

Nice spring weather is in the making. Just look at this snapshot of temps.

I am having a time here in NC hardening off. Winds are 20 mph with gusts 32 to 40 mph. Put up a big wind screen to protect them, but am getting some wind burn. Tomorrow is supposed to be bad, high wind advisory. Will keep them in their protected spot, but bring them in tomorrow night as there is a frost advisory. Crazy weather, 80 today, 70's the past week and next week with 50 lows except tomorrow night. The winds are terrible.

Jennie

Jennie,
Get some cardboard boxes and put several of then in each box. And put the boxes next to each other.

Seysonn

Good idea Seysonn. I took the large card board box the screen door screen is stored in to make a wind block and that worked pretty good. Forecast has reduced the gust speed for today and the winds have shifted to NNW so they should be okay on my south facing back porch. They have been out all day and night since Tuesday, but will come in tonight with the possibility of frost. after tonight the 10 day forecast looks great.

Jennie

Have mine sitting out in the shade today and just finished putting up the greenhouse. Chance of frost tonight but after that the forecast looks good albeit a little wet. Will put them in the greenhouse tomorrow and see how it goes.

Hey Sey

First time with LED grow lights and made a mistake of plating too early, lesson learned. Have another month before outside and they're huge already after only about 3.5 weeks. Here is a picture from last week.

BTW, those are 5 plants in 1 gallon pots, they look much bigger in person

Hi Vance
We all haste in doing so. Some of mine are big too.

To keep them from growing even bigger faster, I suggest doing the following: :

1- keep them in cooler temperatures 55-60F
2- Stop fertilizing
3- Water them when they are thirsty
4- Pinch off a lot of lower leave; Less leaves = slower growth.
5- keep the light on closer

Good luck

Sey

I have them in garage and will put them outside this week to start a long hardening off process. With these grow lights I found out it it doesn't really matter how close they are to the plants. Thanks for your input. BTW I already put a small amount of lime around the plants because of all the flowers appearing. Learning a lot with these lights very quickly

The time is near and here.
Tomorrow I will plant out about a dozen or so, from the ones in the cold frame and mini hoop. Finally the night lows are staying in low 40s+. and highs averaging 60F.
My raised beds under black plastic are warm enough (~ 58 -60F)
All systems go. Lift off !
.
Seysonn

I did it..... ~ 20% of my total.

Today I started planting out SLOWLY>
I planted followings:

2 Brandy Boys
1 Cherokee Purple
1 Kelloggs Breakfast
3 Siletz.
1 Polish Dwarf

Tomorrow an Friday I will plant out few more.
There will be 3 nights in a few days with lows @ 38F. So I will let that pass then I will resume planting.

Seysonn

My LFD is less than two weeks away, and the forecast is calling for highs in the 70s and lows of mid-50s. Being so close to the LFD and no dramatic drops in temperatures predicted for the next week, should I still wait until the LFD to plant or should I just go ahead and plant them (they are already hardening off)? I know it's kind of a gamble, but having a second opinion may help me decide what to do.

I always look at the 10 day forecast right before the LFD. If it is ok, I go ahead and plant. I also look at how long ago the last frost happened. if it was a quite a while ago, I hold off. If it was within a week, I figure statistically, that was our last one.

As far as hardening off, I don't make a real big production. I take my 50 plants to the back patio and put them on the patio table and open up the umbrella, tilting it to the side with the direct exposure. I, too, try to wait until a mostly cloudy day. I do this for a week. Here in Charlotte, NC, it seems the wind and sun is what is most important during the process. When the plants have stiffened up enough to withstand the winds and heat, they go in the ground. Usually about a week. During the first week, if it is sunny and hot, I program the irrigation to overhead water several times a day to cool them off.

Tripleone,
I don't blame you. Your 10 days forecast is tempting.
I would wait another 5 days and see how it goes then.
In the meantime get on with hardening off process and then dive in.

Today I planted 2 more. So far a total of 10. The 10 days forecast indicates couple of nights with lows dipping to 38F then back up to mid 40s and highs near 69F. No danger though . I have experience lows as low as 36F many times in the past without any problems.

Seysonn

Weather in a glance across the US of A

get that BLUE stuff out O here. lol

Hello zone 6ers, 7ers, +
How is your hardening off going ?
I see a lot of friendly weather everywhere. No stop complaining. LOL
Actually my part of the neck of woods has not been as good lately. Nevertheless, I continue the process. I let/ask my tomato plants to get tough. Life is not always easy. (you herd me !). It is a tough life but somebody got to live it (garfield)
Big bulk of my plants are in the hoop and cold frame. Night lows are dipping into as low as 38F. come Thursday it is going to be beautiful. My plants should appreciate that after being out in the cold for a while.

Keep on keeping on !
It is a Marathon not 100 yard dash.

Seysonn

Still kind of cold at night. Not frost but cold wind. Tomatoes have been outside day and night for about 6 days now but just in the last couple of nights I've not covered them with remay. They look pretty good. Today is the first day of all day sun for them, so I've put up a barrier to protect from the hottest sun. All this fuss is for my heirlooms, the Juliet I already planted in the garden about a week ago since it had gotten so big and it doesn't seem to mind the weather too much. It is growing and already has flowers.... I give away most of my tomato starts but I learned a lesson last year when I got less then favorable reviews for my plants because I did not harden them off sufficiently. I gave them to seasoned gardeners and told them they were not ready to plant but I guess the process is tricky for them as well as newbie me...

I planted mine out yesterday after leaving them in a shady/late sun spot for a few days. Unfortunately I'm worried about all this rain we're getting today and the end of the week. I hope they don't get waterlogged!

I have had mine in a small pop up greenhouse for the last week and a half. Open during the day as much as I can and closed up at night. They should be ready to go as soon as I can work the garden.

Hopefully you don't get too much rain. 2 to 3" is equivalent to good hand watering. Then it also depend on the kind of soil you have. With fair amount of organic matter it should drain ok. Here in PNW we get rain , rain, rain all the time. I have covered my raised beds with black plastic and just cut a hole for each plant. so most of the rain water will run off.

Seysonn

I made a mistake and my babies got sun scald for the first time. I underestimated the UV's on a 65 degree day and they got burnt. I think they will recover.

I did things differently. From Day 1 of fluorescent lights, Sunlight begins to stream in at a low angle in late February and March in the room and falls where I start them together with the fluorescent light. I adjust the blinds if it gets too hot temperature wise in there, which is what I have to be careful about in March upstairs.

I transplanted them in March directly into their final containers filled only 2/3 and they are placed in the most direct sunlight with the rolled up the second day and are always well-irrigated.

The forecast had a week of rain so I put them outside then, either in my tunnel or under a tree on the driveway, they all go out and are left there. The ones in the hoop are put in their final spaces and under the tree stay there. The humidity is protective and over 90% at night and temperature great as long as they are out by the second week of March. We just as well could have had a freeze then because the extremes can vary here sandwiched between Georgia and Florida, but somebody's got to live here. One night got me at 41 F, but it wasn't as bad as I worried and they were fine. All other nights were over 50 F, mostly 55 F. Now in the second week of April our nightly lows will bottom out at 70 F in a few days, so things move fast. Too fast. By the end of June the party is over.

Now is mid April and time to add the final 1/3 of the containers. The bottom sets of leaves have been removed and air healed, so no one will know if one or two had a little heat damage (which is actually due to the reflected heat and would happen to any leaf to some extent) and they've done their job and been removed, and in two days that part of the stem will be buried ;-)

PC

PC, that's a great idea, to put your light setup where they also get some natural light. Why do you wait to fill your final containers the last 1/3rd? Is it so you don't have to remove quite so many leaves at the time of transplant?

I am terrible about hardening things off, I have a habit of putting something outside and saying "I will leave it for one hour" and then forgetting about it entirely. The next day, I'm like "whoops! I left you outside all night!"

Fortunately I have a bit of a cheat now. I have a sunporch that faces south and also has windows to east and west. It is unheated but probably stays a couple degrees warmer at night. During the day it definitely gets warmer than outside if the sun is shining in. It seems if I have something in the sunporch, it is used to the nighttime temps and therefore doesn't die if I forget it outside :-)

This year I started some herb seeds on the south windowsill inside, then once they sprouted, I set them on the sunporch for a while before setting them outside. This seemed to work well although this probably wouldn't fly for tomatoes. I'd love to add some lights and heat to the sunporch, but there's no outlets out there :(