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RE: Seeds Under Lights Versus Greenhouse

	Although a greenhouse is nearly always preferable for
germinating and growing on of seedlings because of the greater amount of
light, broader spectrum of light, better circulation of air, etc., there
is no reason why you can't enjoy growing a very wide range of wonderful
plants from seed under lights.  There are lots of other factors in your
success, however, in addition to the lighting itself.
	We were fortunate in our former home to have a cool basement
that remained about 55 degrees Fahrenheit throughout the entire winter
and that had a window for ventilation in the early spring when the
weather was warmer and before the seedlings were ready to be hardened
off and then planted out.
	For about five winters, we grew about 1500 plants each
year(mainly rock garden perennials and small cushion alpines) from seed
under lights in the basement.  We had wonderful germination and the
seedlings almost always lived.  In fact, the project was so successful
that we eventually stopped because we no longer had room, time, or
energy to plant the seedlings (or sell them).
	We had plastic six-packs placed inside large plastic
sweaterboxes on a table where the lights were attached with clothesline
and old sausage-shaped window weights in a marvelous "pulley" system
that my husband devised.  This way, when the seedling were tiny, the
lights could be lowered to just above the small plants and then easily
raised for watering and inspection and kept at a higher level when the
plants were taller.  We had a timer and left the lights on for about 16
hours.  After the second season, we switched from the regular "cool
white" fluourescent bulbs to the "warm white" with a wider spectrum and
thought that the results were even better.
	Usually, we only kept the clear plastic lids on the sweaterboxes
in the very beginning.  Once seeds had germinated, we removed the lids,
misted the plastic cell packs inside with a very fine mist, and had a
small fan going to provide circulation.  The mix itself was a sterile
light soilless mix (Pro-Mix) like you would use for potting houseplants
with half again addition of coarse builders sand.
	One trick we used was to soak the six-packs just BEFORE sowing
in very hot tap water (with a little very dilute fertilizer in it).
This way, the water helps dissolve inhibiting chemicals in the seed coat
to speed germination.   Later watering, of course, should NOT be hot
water.  For later watering, in the beginning, try using a device that
creates a very fine mist (you can add very dilute fertilizer to the mist
water when the seedlings are already showing some growth), then later
you can use a turkey baster to add water carefully to selected portions
of the six pack as needed, and then finally, when the seedlings are
pretty large, you can use a regular watering can.
	This sequence of hot water, lid on, germination, lid off and
misting, along with cool night temperatures and good air circulation,
should give you good results  for the vast majority of perennial
flowers.
	However, for some seeds, especially in the legume family such as
astragalus, you may also need to use an emery board or very fine
sandpaper to nick the coat (called "scarifying") before sowing.  There
are also some genera, particularly woodland wildflowers, that profit
from a period of weeks in the refrigerator, with the six-pack sealed
inside a plastic zip bag before going under the lights.
	Also, for tiny seeds, we would sprinkle them on top of the mix
and then add a final sprinkle--very thinly--of turkey grit.  You can use
this turkey grit, and we sometimes did, as a topping for all of your
seed pots. This protects the seeds when you mist and provides some
protection from crown rot on the seedlings, especially for western
plants that dislike high humidity.
	We did include impatiens in the plants we grew because I liked
to have lots of annual impatiens to fill in the shady fern and
wildflower beds and to plant out under shrubs.  BTW, for impatiens, buy
one of those BLUE plastic report folders in the school supplies section
of the drugstore and put it over the seed trays--it filters the light in
such a way as to speed and improve germination greatly.
	In addition to impatiens we grew, literally, HUNDREDS, of
species of rock garden plants, usually from seed acquired in the seed
exchanges of national and international seed societies.  SO .... don't
be discouraged.  and Enjoy!


Susan Campanini
in east central Illinois
zone 5b, min temp -15F×
e-mail:  campanin@uiuc.edu

Dr. Susan Campanini
Coordinator of Instructional Development
Guided Individual Study
University of Illinois at Urbana-Champaign
302 E. John St., Suite 1406
Phone:  (217)333-1320
E-Mail: campanin@uiuc.edu
 

> ----------
> From: 	ronavar
> Sent: 	Tuesday, May 27, 1997 9:25 PM
> To: 	seeds-list@eskimo.com
> Subject: 	Seeds Under Lights Versus Greenhouse
> 
> I am new at starting seeds, and have used lights over the past couple
> of
> winters.  Here in Ontario, January days are short.  I always thought
> that leaving the lights on for 16 hours would be preferable to a
> greenhouse, making the plants believe we were having longer days than
> we
> really would be during the winter.
> 
> But recently I had a conversation with a man who grows plants for the
> main street of our town, and he mentioned that a greenhouse is
> preferable to lights, and that many plants grow better in a greenhouse
> than under lights.  His comment was "impatiens will do ok under
> lights,
> but that's about it".
> 
> Does anyone care to comment on this?  If it is true that some plants
> respond better to greenhouse conditions, and others to lights, does
> anyone have lists of which plants prefer which, and which plants don't
> care?
> 
> Would really appreciate some direction on this subject.
> 
> Thanks in advance,
> Heather in Markham, Ontario
> Cda Zone 6 / USDA Zone 5
>
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