• Do you need help identifying a 🌶?
    Is your plant suffering from an unknown issue? 🤧
    Then ask in Identification and Diagnosis.

hardening

So, how long should it take to harden my plants off so I can leave them outside? Is there a better way to do it other than leaving them out for an hour it so, then bringing them for the same time?
 
I usually do a few hours of shaded or filtered morning sun and then bring them in. A few days like that and increase the time and add some afternoon hours. Eventually all day (as long as it's not to hot) and back in. And finaly all day and night. Usually a 2 to 3 week process for me. When I come back inside, it's a room with East, North, and West windows. Can't leave them to long in the room cause aphids will find that young new growth on select plants. Vigilance!

Hope this helps.

Mike
 
3 years ago I got lucky and planted out with no hardening on the beginning of an overcast week. 2 years ago a full week of sun killed them all, so last year I did the in and out thing. I would love to find a different way too.
 
I agree with the last to replies, acclimate them gradually, the plants can become sunburned very easy. Try to find a shady area, your plants will still receive ambient reflected light while in the shade, I like to expose the plants to some gradual late afternoon sun. Doing so over a 2 wk period. Overcast or cloudy bright is what I hope for. If the plants gets burned, the leaves will start to take on a translucent look. That's not good and chances are that the plant will not recover to full potenial. You could place plants under a patio table or umbrella, just make sure they get watered in the morning. Black gal containers tend to heat up and the soil will dry up quickly
on you.

Greg
 
3 years ago I got lucky and planted out with no hardening on the beginning of an overcast week. 2 years ago a full week of sun killed them all, so last year I did the in and out thing. I would love to find a different way too.
Easy bro, put yours on table under your carport near the front where the sun only gets light there for a little bit if at all. I'd leave them out for a week of indirect light, then start progressing them into the light an hour or so at a time for a couple weeks.

I agree with the last to replies, acclimate them gradually, the plants can become sunburned very easy. Try to find a shady area, your plants will still receive ambient reflected light while in the shade, I like to expose the plants to some gradual late afternoon sun. Doing so over a 2 wk period. Overcast or cloudy bright is what I hope for. If the plants gets burned, the leaves will start to take on a translucent look. That's not good and chances are that the plant will not recover to full potenial. You could place plants under a patio table or umbrella, just make sure they get watered in the morning. Black gal containers tend to heat up and the soil will dry up quickly
on you.
Greg
Good info!
 
Wow this is a topic I am very interested in and from what I'm hearing I think I need to start my grow tomorrow instead of next week . So I'd love to hear some real world experience about how long this process takes and what is the goal? Say you start to harden and it's rainy and cloudy everyday does it still work? Or do you have to get them used to the sun?I live in Portland Or and will be hardening in May will 2 weeks be enough? And what if there is no sun?
 
Hardening is the f***ing bane of my existance! I lost a lot of plants last year and had an extremely slow start for the others, took 2 months for them to recover. Last year I would place all of the plants in my garage with the west facing bay door open letting them get indirect light for 3-4 hours a day for the first week. Then I moved them outside of the garage where they were shaded in the morning for about 4-5 hours a day. Finally moved them into the open field but under tables so that they only received direct light for the first two hours of the morning then moving them back inside around 4 PM before direct sun in the evening. Thats when they burnt to a crisp! It didn't help that the wind decided to blow 30-40 MPH everyday for 3 weeks either.

This year I will have 80-90% of my plants in the greenhouse until they are ready to plant out. Hopefully they will not need hardening as their light source is 9-10 hours a day of sunlight (filtered at 78% by the polycarbonate) followed by 2-3 hours of light from a HPS.

My growroom plants are on 20/4 cycle under fluoros, I am planning on moving them to the greenhouse (in a shady area) about 1 month before planting out. I am thinking that a couple of weeks shaded in the greenhouse, followed by a couple of weeks unshaded in the greenhouse should have them sufficiently hardened.

I actually have a thread in the grow tech forum to track this experiment. Any feedback would be appreciated.

http://www.thehotpepper.com/topic/27972-greenhouse-with-hps-vs-fluorescent-grow-room-experiment/
 
Wow this is a topic I am very interested in and from what I'm hearing I think I need to start my grow tomorrow instead of next week . So I'd love to hear some real world experience about how long this process takes and what is the goal? Say you start to harden and it's rainy and cloudy everyday does it still work? Or do you have to get them used to the sun?I live in Portland Or and will be hardening in May will 2 weeks be enough? And what if there is no sun?
I do mine on the front porch for 1-2 hours a day for a week then up it to 4. I keep a close eye for leaves starting to fade/whiten. If I see that they are right back under the lights inside. If you get lucky enough to have your week of hardening be overcast you should have no problem. In 2009 I was just getting into starting early instead of seed to garden. Had no clue of hardening and planted out 30 plants. Tiny leggy little things and it just so happened to be overcast all week. Great little garden that year. 2010 more plants and again plant right to the garden no hardening, I knew about it now, but obviously didn't need it, bigger leggy babies and past year experience. As the bright sunny week cooked and killed them I remembered '09's overcast week. Live and learn.

But yeah 2 weeks should be fine.
 
I find a 2 week transition to be optimal. As long as the night temperatures aren't unreasonable, you can just leave them outside in a shaded spot for the first few days, move them to a spot that receives only a couple hours of morning light for a few more days, then finally gradually acclimate them to full sun. As was said, if you can time this so the weather is a bit overcast, this last stage is much easier.
 
I'm just a few weeks from starting this process and dreading it. I seem to run into major catastrophes with hardening off plants...everything from freak thunderstorms to me dropping them on their heads while carrying them in or out, to sunburn or windburn. I think they acclimatize to sun at the same pace I do, so maybe I should sit out with them in my bikini and if I get too sunburnt or cold, I should assume they do too. :lol:

I vaguely remember my grandfather having a box he built for hardening plants. Tall, wooden sides and a glass top on a removable hinge. The sides provided wind protection, and he could prop open the lid just a little on cooler days while letting them get their sun, but also could start out by covering the glass to provide some partial shade early on. When it was close to planting time, the lid could come off entirely during daytime and just put on at night or eventually, only if there was a frost expected to keep them all cozy inside. Though, like everyone else, he spent at least a week carrying them outside and back inside daily...maybe longer.
 
I'm a cruel plant father. Once I put them out I leave them out unless the temps drop back to dangerous levels. I anticipate some having sunburnt leaves due to lax monitoring. I just try to position them so that they're spared from the afternoon sun at first. My Rocoto overwinters are showing signs of burn, but at the same time, new growth is shooting out, and since the winter growth is kind of leggy anyway I'm not worried.

Right now some of my plants are getting a crash course in how much it sucks to be out in a storm... I always start extra seedlings anticipating some will be killed off for one reason or another, then I just plant the survivors. Nature is cruel, and I can only baby my plants so much before I get tired of it and push them out of the nest. I try to stagger it so I have some inside in case some freak accident happens and I lose my first set...
 
Another question on this topic: Is there a such thing as too early to harden off?

I have a bunch of seedlings that are just today beginning to sprout true leaves. Well, their grow box is in my room so over the past 3-4 days I have been putting them outside under a shade screen for growing amounts of time every day (temperatures going from about 70 in the morning to 94 in the afternoon), then putting them back under the flourescent lights by night (I read 24/7 lighting is ok for first month or so). By today I left them out basically all day under the screen. Seems like in a week or so they could be weened into direct sunlight as is.

Is this a bad idea? They seem fine as of this afternoon, but like I said none really has leaves to show damage yet...

It seems a shame to relegate them to a crappy flourescent light in a box when we have 12+ hours of pure sunshine available everyday here. Ideas? Experiences?
 
Check out Romy6's (Jamie) GLog and you will see that he has had success planting seeds outside and letting them grow to production in the elements. Gotta love the Fl weather.

I am definitely thinking about augmenting my light schedule with outdoor time next season. I really don't think it is too early to get em outside, as long as you shade em and introduce them to fill sun at some decent pace. But with the winter that we got this year, I found myself in 75 degree weather and the plants indoors. I think they would benefit from some sunlight augmentation.

I am hardening my plants off right now, and they are outside 24/7. Luckily the front of my house faces east, so I can put them on the porch under the owning and they get about 6 or so hours of direct sun, then shade for the rest of the day. I can tell some are stretching for some more sun, but nothing bad. I was gonna put them out in the garden to get two days of full sun before being planted Friday, but looks like a freakin monsoon is comin my way. Instead I am gonna put them in the front yard so the wife can just pull em on the porch if Heaven opens up.
 
Its is optimal to harden in increments at least 4-5 days!
But it can be done ALOT quicker!
When I first stick a plant out into full sun I watch it closely,,
when it first starts to droop, 15 minutes prolly,, I put it back in tha shade.
about 15 minutes it perks back up!
Then again in the sun,, I may get close to 30 minutes this time, back in the shade for like 15 minutes till it perks back up!
Repeat as plant allows!

Now to make this easier!
Find your own shade but I stick em in tha full sun in trays,
and cover with my kids trampoline!
Remove tramp and repeat!!
Hardened 275 plants in one day this year!!

:cool:
Kevin
 
Anybody have any experience on whether or not plants that get some indirect sunlight from windows do better with hardening off vs. plants that go directly from lights?
 
I actually get direct sunlight for 3-4 hours a day through my window and I just throw my plants out on the deck for a few hours whenever it's warm enough to do so. Direct sun for 5+ hours hasn't burnt them yet, granted the direct sun I expose them to now is nowhere near the intensity of the direct sun I the middle of summer.
 
Window plants do better...but still need a little hardening. As long as they were getting some good direct sun through the window.

My hardening process is working well. I have a south facing lattice covered porch. They go in the center to start with and get maybe an hour of early morning sun, then filtered all day and finally about an hour late afternoon. I move them a few feet each day to the West end of the porch. By day 5 or 6 they are getting full sun from around 2pm through dark and are good to go. The great thing about this is there is no baby sitting involved. I can go to work and know that they're not frying. I can start them hardening on the weekend and the following weekend they're ready to be moved out to the garden.
 
Back
Top