Once a seedling has it's true leaves...

Qweniden · March 13, 2011

....how long till its ready to to be hardened out doors?

Also, how long does a plant need to harden before its put into the ground?
Thanks!

kath · March 13, 2011

There are a lot of guides to hardening off, differing slightly in recommendations. Think there was a good thread on this topic here recently.

You can keep it outdoors any day that it's warm enough and bring it back in for additional light hours and warmth at night. I try to do that as much as possible because it saves having to spend a week or more to harden them off just before planting.

How long it takes depends on the conditions such as how much sunlight and wind it willget. It's important to take it really slow in the beginning and keep an eye on them for any "limpiness" which means they've had enough. You can ease into it by providing protection from the wind, using shadecloth, etc. but a lot depends on how many plants you have and how much work it is to be able to bring them in and out each day, too.

Qweniden · March 13, 2011

Quote:

Originally Posted by kath

There are a lot of guides to hardening off, differing slightly in recommendations. Think there was a good thread on this topic here recently.

You can keep it outdoors any day that it's warm enough and bring it back in for additional light hours and warmth at night. I try to do that as much as possible because it saves having to spend a week or more to harden them off just before planting.

How long it takes depends on the conditions such as how much sunlight and wind it willget. It's important to take it really slow in the beginning and keep an eye on them for any "limpiness" which means they've had enough. You can ease into it by providing protection from the wind, using shadecloth, etc. but a lot depends on how many plants you have and how much work it is to be able to bring them in and out each day, too.

Thank you for the great information.

To simplify my question a bit: I am wondering how long does it take from the first true leaves until they are big enough to plant outside? I'm not sure what the rate of growth will be from this "just sprouted" stage to having a baby plant that can go into the earth.

kath · March 13, 2011

Sorry, guess I misunderstood your question.

Most folks say you can plant out from 6-8 weeks from sowing. Last year I had plants from seeds that were sown mid-May (14th, I think) after a frost killed many siblings. After sprouting, they spent their days in the sun supplemented with lights for a couple hours after they came in for the night. They were plenty big for the garden on June 7th. That's about 3 weeks. It may have been all about being outdoors everyday - don't know as it only happened last year. Made me think twice about starting so many plants early, though, since they almost caught up with the March sown plants.

**carolyn137** · March 13, 2011

Just addressing a couple of points brought up.

You sow seed for germination in a pan or container of some kind. Then when the seedlings are about two inches tall you transplant them to hopefully pleastic cells in an insert in a nursery tray or two inch or so pots.

That first transplant is necessary for the roots to develop the right kind of root structure, fibrous rather than a tap root structure.

I never pot up as so many do b'c all that does is to encourage a fragile fibrous root structure in a pot when you want that inground. So when I put out my plants they're rootbaound and that's what I want them to be

I grow my plants on in those 2 X 2 inch cells until they're ready to be hardened off when they're about 6-9 inches tall. So about a week before set out time is time to put them outside for hardening off. And you put them out when you know that the temps aren't going to go below about 40 F, if that cool.

If heavy rain or high winds or freezing temps occur put them under shelter, but do NOT take them back into the warm house or you'll just reverse all that you're trying to accomplish by hardening them off.

What you're trying to do is to toughen up the leaf cuticle, the top part of the leaf, so that when the plants are put out they'll be less susceptible to windburn and sunburn.

March 13, 2011	#1
Qweniden Tomatovillian™ Join Date: Apr 2010 Location: Sacramento, California Posts: 267	Once a seedling has it's true leaves... ....how long till its ready to to be hardened out doors? Also, how long does a plant need to harden before its put into the ground? Thanks!

March 13, 2011	#5
carolyn137 Moderator Emeritus Join Date: Jan 2006 Location: Upstate NY, zone 4b/5a Posts: 21,169	Just addressing a couple of points brought up. You sow seed for germination in a pan or container of some kind. Then when the seedlings are about two inches tall you transplant them to hopefully pleastic cells in an insert in a nursery tray or two inch or so pots. That first transplant is necessary for the roots to develop the right kind of root structure, fibrous rather than a tap root structure. I never pot up as so many do b'c all that does is to encourage a fragile fibrous root structure in a pot when you want that inground. So when I put out my plants they're rootbaound and that's what I want them to be I grow my plants on in those 2 X 2 inch cells until they're ready to be hardened off when they're about 6-9 inches tall. So about a week before set out time is time to put them outside for hardening off. And you put them out when you know that the temps aren't going to go below about 40 F, if that cool. If heavy rain or high winds or freezing temps occur put them under shelter, but do NOT take them back into the warm house or you'll just reverse all that you're trying to accomplish by hardening them off. What you're trying to do is to toughen up the leaf cuticle, the top part of the leaf, so that when the plants are put out they'll be less susceptible to windburn and sunburn. __________________ Carolyn

March 13, 2011	#2
kath Tomatovillian™ Join Date: Jan 2010 Location: zone 6b, PA Posts: 5,664	There are a lot of guides to hardening off, differing slightly in recommendations. Think there was a good thread on this topic here recently. You can keep it outdoors any day that it's warm enough and bring it back in for additional light hours and warmth at night. I try to do that as much as possible because it saves having to spend a week or more to harden them off just before planting. How long it takes depends on the conditions such as how much sunlight and wind it willget. It's important to take it really slow in the beginning and keep an eye on them for any "limpiness" which means they've had enough. You can ease into it by providing protection from the wind, using shadecloth, etc. but a lot depends on how many plants you have and how much work it is to be able to bring them in and out each day, too.