The Hassle Free Way to Harden Off Seedlings

what is going on everyone welcome to

another very exciting episode right here

on yeah my gardener Channel it's a brisk

one today almost coat weather almost

it's about 54 degrees so it's pretty

chilly for just a long-sleeve shirt but

you know what I put the coat away I

didn't I said I'm not pulling that thing

out until it's fall so I'm out here

freezing my buns off for you so I hope

you guys enjoyed this episode this was

gonna be a fun one because we're

actually talking about a kind of a hot

topic right now for this time of year

which is hardening off seedlings we get

asked a lot how do i hard enough

seedlings should i hard enough seedlings

which seedlings should be hardened off

and just anything hardening off related

so whereas we're going to talk about so

the first thing is what is hardening off

for those of you that might never have

heard this term before hardening your

plants off basically means acclimating

them to the sunlight you might think to

yourself what do you mean acclimating

them to the sunlight that doesn't make a

whole lot of sense and the thing is is

if you have them in a grow room in your

house those lights that you're growing

them under regardless for how strong

they are I mean they could be the

strongest grow light commercially

available you're bringing your plants

outside the Sun is gonna be fifty to a

hundred times stronger than that grow

light that you have even on this day

which is super overcast and real cloudy

it's still stronger than any grow light

you're going to have in your house so

what happens is when you have your

plants inside or even in a Gras even in

a greenhouse like a nursery that's using

like poly plastic or shade cloth things

like that you know you might walk into

the greenhouse and think it's just as

bright as it is outside of the

greenhouse but it's not the case a lot

of the sun's energy is actually being

filtered through that plastic or

reflected off of that plastic sure some

still comes in but the plants notice

that and the plants have built-in

mechanisms to protect themselves from

the Sun just like you and I put on

sunscreen they kind of put on sunscreen

it's actually a it's actually a

protectant that they build up over time

to protect themselves against the harsh

sun but when it's indoors that Sun

protectant is actually not it's not

nearly as thick and it's not nearly as

strong because it doesn't need to

the Sun actually will the Sun will

actually burn the leaves and that's what

we want to protect against on Sun scald

or sunburn they're both kind of the same

thing two terms that are tossed around a

lot Sun scald is where your leaves would

get really silvery really thin and it

just looks like fried or burnt that's

caused from the really strong Sun and so

because the plant has not had a chance

to acclimate to the strong Sun it just

fries just like your skin does on you

know on a really sunny day if you sit

outside the whole day so the next

question is is how do we harden off

plants basically the the long-standing

tradition has been kind of it's uh it's

like the spring ritual bring the plants

out for two hours take them in for the

rest of the day bringing them outside

for four hours take them inside for the

rest of the day and then you get a good

point you know six hours out the next

day and in for the rest of the day in

two hour increments until you get up to

about ten hours then you can leave in

them out for the whole you know pretty

much for the whole day because of the

fact that the Sun is really only

strongest during Peaks you know during

the peak Sun hours which are about one

to about four so you know anytime in

between there you're pretty safe you

want to get them through that kind of

long period of Sun and then they're

pretty much fine to leave outside for

the rest of the day and that's why it's

such a long process it's four to five

days sometimes to get your plants fully

acclimated but there's a but and what if

I told you that this was actually a

really easy way to harden off your

seedlings with far less hassle because

I'll tell you what I hate bringing my

plants out and in and out because I've

got a lot of them I've got a ton of

plants to bring in and out last thing I

want to do is do that each day for a

whole week it's just really annoying

what I like to do is I like to leave my

plants in the grower room under the

lights until I have some overcast days

like this the overcast days sure the Sun

is still far stronger than any

commercial available grow light you're

ever going to find however it's not

strong enough to cause leaf burn so what

I like to do is I like to wait for these

days right here with a nice and overcast

I seize that opportunity and I leave my

plants out for the entire day and to

prove that I'll go get some of the

plants that I've actually that I have in

the garage that I'm going to pull out

for the rest of the day so these are

the plants that I've been hurting off

for the past two days we've had three

days of overcast weather the one day was

too cold to bring the plants out so I

don't want to risk them dying so I

brought them out yesterday I'm gonna

bring them up today and then tomorrow is

gonna be overcast as well

three overcast days I can leave them

outside the entire day and that usually

equals about a whole week of hardening

off it's going to give them acclimated

to the wind it's gonna get them

acclimated to the Sun and it's also

going to get them acclimated to to the

the temperature because the temperature

inside is far more different than it is

outside you want to you don't want any

form of stress so what I like to do is I

like to keep them outside just during

the day when it's the warmest because

obviously springtime weather is usually

a lot colder at night than it is inside

we're talking like low to mid 40s versus

inside we're in the low to mid 70s and

so there's a big temperature difference

too so I'm getting them acclimated to

all three of those things one thing

you'll notice is when they start

hardening off you'll know that they're

properly hardened off when the leaves

are very very thick you see when they're

inside the leaves are not as thick

because the plant the plant leaf

actually will be very thin much like you

can see this leaf here show you this

leaf see see how thin and droopy that is

I wish I could take a diet there a

thickness of this leaf compare that to

this leaf you can see hopefully you can

see it's about three times thicker

believe it or not and what that's doing

is it's actually building up its sun

protection the sun protection is

essentially a thicker leaf because the

thinner leaf is the stuff that's going

to burn these might still burn on a

really on a really bright day these

might still burn because how thin they


but those older leaves they'll be fine

and they'll be long gone it's these new

leaves that I want to protect these are

the ones that are just coming out so I'm

protecting these by hardening them off

by hearting the plant off and I'm doing

that by just leaving them outside during

an overcast day it's really simple and

that way I don't have to worry about you

know if I'm at work right have to come

home only like for God doesn't really

matter I just wait for those overcast

days it's a perfect combination now what

do you do what do you do if you have

overcast days and then a

any day in between like let's say

tomorrow was a sunny day what do I do

really simple if the day is really sunny

I'll set the plants out during the

morning for the morning Sun and I set

them in a way that I can tell where

there's a shadow right around one

o'clock remember I said that the peak

Sun is at around one o'clock to about

four o'clock so I don't want them to get

peak Sun that'll fry them and they'll

definitely it'll definitely cause harm

to the leaves so I instead I actually

kind of scope out the area see where

there's going to be a shadow at around 1

o'clock peak Sun and then I make sure

that that shadow is still existing at

around 4 o'clock a great way to do this

is to use your house your house is a

wonderful block of Sun or a shed or a

barn anything like that and then when

they get Sun in the morning they're

gonna get Sun all the way until that

shadow forms and that's gonna be a great

way to get them just a decent amount of

Sun but not too much because again in

the morning the Sun is lower in the sky

that means that the the angle of the Sun

is a lot less direct on the plants

meaning that the risk of Sun scald or

sunburn is going to be far less so I

really hope that you guys would use that

tip as well because it really does help

I have never had a huge issue there's

only been one year where I've had an

issue with Sun scald and it was because

I just kind of rushed the process like I

said I typically prefer about three days

to is kind of pushing it that third day

really helps to just kind of helps to

ensure that they're going to be a lot

stronger now the question always does

come up about rain what if rains in the

forecast I love rain

I love range so much in early spring and

there's nothing better than leaving the

plants out during a nice spring rain as

long as there's not really cold rain

where it's gonna shock them that's

totally fine I left my plants outside

yesterday it was raining it was about 51

degrees I think and it was an awesome

spring rain the plants just greened up I

got all that dissolved oxygen from the

sky lots of nitrogen and things like

that that actually helped to green up

the plants so they got that as well so

they got a little bit of a fertilizer

just from sitting outside and they also

were not accustomed you know they were

also not being exposed to that strong

Sun and they're getting accustomed to

the growing conditions so it's really a

win-win situation all around the final

thing I want to talk about our which

plants should you harden off and we get

this question a lot is

are there any plants I can just move

directly outside or then he are there

any plants that I don't have to harden

off as much and the answer is no not

really in fact all of them need to be

hardened off some actually need longer

than others I usually say the bare

minimum is about three days but what you

want to do is you want to let the plant

tell you if it's hardened off or not

again look for those really rigid really

green really sturdy leaves if you don't

have that yet you might need a couple

more days or you might need a day and

just again let that plant tell you

because it happens really quickly once

you get them outside one of the biggest

mistakes I see filmmaking is moving

there cold weather stuff out in fact it

has happened to us more frequently with

our cold weather crops then are things

like our tomatoes and peppers typically

because we're very careful about those

you know we really baby them because

they take so long to grow whereas our

cold weather crops like lettuce broccoli

cabbage things like that you know it's

it I hate to see they're kind of a dime

a dozen but we tend to throw them out a

lot quicker because like oh they can

handle the cold weather throw them out

those are heck's are the ones that I

typically get Sun scald on more

frequently because of that you throw

them out kind of willy-nilly you think

they have nice thick healthy leaves they

think they're gonna be fine

they're typically not so those also need

about three days of hardening off and

that's why I said there is not a single

plant that I would not recommend

hardening off I also recommend hardening

off even if you get from the greenhouse

like I said the benefit to getting them

from the greenhouse or a nursery

obviously you're not starting them from

seed I get it I prefer if you do start

them from seed because you're gonna save

a lot of money and you're gonna have the

sense of satisfaction of growing it

yourself but if you get them from a

greenhouse or a nursery I typically say

about a day or two is all you need to

harden them off you just want to get

them outside away from any away from any

cover where it's gonna be filtering the

Sun and that way they can they can

harden off a little faster and a little

better so that's really all there is to

hardening off I'm gonna bring the rest

of my plants out and we're gonna get

them all all ready to go in the ground

it won't be long one final tip for all

you is really gonna help out is make

sure not to set your plants right on the

ground I always take my plants and

either I put them on a card table or I

set them up here on my on my wood rack

here my wood pile because I don't want

them right on the ground

being on the ground does two things

that's very risky one is cold

temperatures the coldest air is close to

the ground and so if you can elevate

them even a foot and a half off the

ground there's about a three degree

temperature difference that's a huge


when it comes to just the amount of

stress that your plants are going to be

kind of acclimate to temperature stress

sunlight stress and wind stress are

three big stressors so if you can help

reduce the amount of stress from

temperature changes it's gonna help out

also we're gonna get some radiant heat

bouncing back from the house that's

gonna help to kind of keep the plants

even that much warmer so really helps

out to to reduce the stress and then the

final thing that helps with is being out

of the you know kind of being out of the

reach of hungry mouths I can't tell you

how many times people have written to us

saying I put my plants outside and now

something's eating them what am I going

to do I can't even get my garden started

I'm already a target and that's because

they're young seedlings young seedlings

are tender seedlings and pests

regardless regardless if it's a slug a

rabbit a mouse it doesn't matter they

target the youngest tenderest plants

because they're the most nutritious so

if you leave your plant until you leave

your plant elevated until it can kind of

get hardened off and start growing

strong before you move into the garden

it can be a little less susceptible to

being eaten by pests so I hope that

helps I hope these tricks and tips

really get you off to the races and get

your plants hardened off I hope you guys

enjoyed and I hope you learned something

new as always this is Luke from the my

gardener Channel reminding you to get

out there grow a garden grow big or go


it'll catch you all later see ya