From: gwv@eastrg2.cray.com (George Vandenberghe)
Subject: Re: Seedlings under lights and legginess
Organization: Cray Research, Inc.
Distribution: na
Date: 4 Jan 93 13:02:01 CST


In article <1992Dec31.222454.16873@mintaka.lcs.mit.edu>, dmiller@theory.lcs.mit.edu (Dick and Jill Miller) writes:
|> >From: rlwilliams@gallua.gallaudet.edu
|> 
|> >Hi,
|> >        for the first time I'm thinking of starting some seeds indoors...
|> >probably tomatoes and peppers. I have tried the window sill rout in the 
|> >past but that has usually led to really leggy plants plus many of them 
|> >didn't survive the transplant (the peppers' stem wilted right where it 
|> >meets the ground and they plopped right over and died). Sooo, this
|> >year I am thinking of getting one of those kits with a light and a shelf
|> >for starting plants indoors. I got about 10 (!) gardening and seed catalogs 
|> >this week so I'm ready to start looking.
|> >        I wonder if you have any advice for me. Do these things work?
|> >Any particular brands better than others? Any special feature I should make 
|> >sure I get?   Thanks
|> >
|> >skip
|> >rlwilliams@gallau.bitnet
|> >
|> Lights work pretty well.  You should be aware that lights alone won't 
|> necessarily keep plants from getting leggy.  They should also have fairly 
|> cool temps (55-65F) during growth (but not during germination when the 
|> seeds need to be warmer (~75F?).
|> 
|> --Jill
|> 
|> 
|> --
|> A. Richard & Jill A. Miller            | Miller Microcomputer Services |
|> InterNet: dmiller@im.lcs.mit.edu       | 61 Lake Shore Road            |
|> Voice: 508/653-6136, 9am-9pm EasternTZ | Natick, MA 01760-2099, USA    | 
|> 

    The flourescent fixtures with two or four tubes work a lot better
than the fixtures with one tube.  Grow lights will give better results
than cool or warm white tubes but you can compensate by increasing the
white intensity 50-100% with more tubes/closer spacing.  Avoid the
incandescent grow lights; they put out mostly heat and are meant
primarily for making colors LOOK greener and brighter when the plant
is being shown.
     Seedlings that are grown under plant lights need to be hardened
off before planting outside.   In particular they should not be 
exposed to direct sun but should instead be left in filtered shade
such as under a flowering maple tree until they have made some new
leaves outside.  Direct sun causes a condition called sunscald where
the chloroplasts in the leaves are killed and the leaves look bleached.
It takes about 12-24 hours after exposure for symptoms to develop.
This is true even for sun loving plants.  Leaves that develop outside
develop tougher chloroplasts which are however less efficient in dim light.
Hardening off against sun takes 1-2 weeks.  
     If your seedlings have long pale stems, the stems may sunscald as
well.  Plants with scalded leaves usually recover but scalded stems
are often fatal.
      Plants grown indoors will also benefit from some mechanical
stress such as being grown in the air stream from a fan or being
shaken a few minutes a day.  This will make them tougher and more
compact.  Much of the hardening offf process outside is adaptation
to wind and mechanical stress rather than just adaptation to stronger light.
    I've made it sound much more complicated than it is.  Just
adjust seedlings to outdoor conditions gradually and watch out
for strong direct sun  on unadapted plants and you'll be okay.
From: mortiz@hpprdeb.prd.hp.com (Miguel Ortiz)
Date: Mon, 11 Jan 1993 13:56:13 GMT
Subject: HELP !!  Mail-Order Info
Organization: HP Puerto Rico Manufacturing Operation