Seed starting question
 

When starting seed, like tomato or pepper plants, is it necessary to have a
light on before the seed has sprouted? I plan on using a heat mat for the
first time this year, so the warmth of light won't be needed, but I wonder
if it's still necessary to have light for some other reason?

Thanks

Rob

Seed starting question
 

From: "FDR"

When starting seed, like tomato or pepper plants, is it necessary to have a
light on before the seed has sprouted? I plan on using a heat mat for the
first time this year, so the warmth of light won't be needed, but I wonder
if it's still necessary to have light

Not much in the way of light is needed before seeds sprout but lots of light is
needed once they have sprouted plus cooler temps. While an ambient temp of 75+-
is good for sprouting about 68-70 will be better for growing.

Seed starting question
 

FDR wrote:

When starting seed, like tomato or pepper plants, is it necessary to have a
light on before the seed has sprouted? I plan on using a heat mat for the
first time this year, so the warmth of light won't be needed, but I wonder
if it's still necessary to have light for some other reason?

Thanks
Rob


Pepper and tomato seeds do not need light to germinate, but some seeds
do. And other seeds need darkness to germinate. Parks Seeds has a
pretty good table in their catalog that gives germination info for
flower seeds. I don't know of any vegetables that have specific light
requirements for germination.

Best regards,
Bob

Seed starting question
 

"zxcvbob" wrote in message
...
FDR wrote:
When starting seed, like tomato or pepper plants, is it necessary to
have a
light on before the seed has sprouted? I plan on using a heat mat
for the
first time this year, so the warmth of light won't be needed, but I
wonder
if it's still necessary to have light for some other reason?

Pepper and tomato seeds do not need light to germinate, but some seeds
do. And other seeds need darkness to germinate. Parks Seeds has a
pretty good table in their catalog that gives germination info for
flower seeds. I don't know of any vegetables that have specific light
requirements for germination.

I believe lettuce needs light to germinate. -Olin

Seed starting question
 

Things you plant underground can't tell if there's light or not until
they're on top of the ground. Lettuce, planted on top of the ground,
needs light ... not massive amounts, but enough light to set off the process
that says, hey it's spring, let's grow. Once you have two true leaves,
everything you started will need light, preferably right on top of it 1-3
inches away so the plants don't go stretching toward the light.

"jc" wrote in message
...

"zxcvbob" wrote in message
...
FDR wrote:
When starting seed, like tomato or pepper plants, is it necessary to
have a
light on before the seed has sprouted? I plan on using a heat mat
for the
first time this year, so the warmth of light won't be needed, but I
wonder
if it's still necessary to have light for some other reason?

Pepper and tomato seeds do not need light to germinate, but some seeds
do. And other seeds need darkness to germinate. Parks Seeds has a
pretty good table in their catalog that gives germination info for
flower seeds. I don't know of any vegetables that have specific light
requirements for germination.

I believe lettuce needs light to germinate. -Olin

Seed starting question
 

"jc" schreef in bericht
...


I believe lettuce needs light to germinate. -Olin



"und dann w.s. van leeuwen" antwordet in der
Nachricht:
...

and leeks will only germinate in the dark!

That must be why it takes so long! Back in November when I started mine
outdoors, we had less than 10 1/2 hours of daylight per day and it took
nearly 3 weeks before they sprouted - the charts say 7-12 days. -Olin

Seed starting question
 

"Tim B" wrote in message ...
Things you plant underground can't tell if there's light or not until
they're on top of the ground. Lettuce, planted on top of the ground,
needs light ... not massive amounts, but enough light to set off the process
that says, hey it's spring, let's grow. Once you have two true leaves,
everything you started will need light, preferably right on top of it 1-3
inches away so the plants don't go stretching toward the light.


Ok. This is not a troll, and I really hope it doesn't seem that way.
I'm planning on getting a grow light for the first time this season,
after doing some mild indoor and outdoor gardening for a few years.

The whole thing about putting the light so close seems a bit
confusing. (I'd like to use just one or two lights for all of my
plants so I don't have to spend a fortune on lights.) The SUN is
pretty far away, so why is it such an issue to have the lights so
close to the plants? I know the answer is so they don't stretch out
and get spindly, but why does artificial light have that effect? I
know this must seem like a really idiotic question, but none of my
gardening friends seem to know the answer.

Jeffrey

Seed starting question
 

There's an astronomical difference between the amount and type of light
that the sun puts forth, and that of a couple of puny fluorescent bulbs.
The light from the bulbs begins to diffuse with distance--these are not
lasers!--so you need to keep the seedlings within a few inches of them.
Hang the light on hooks from chains, so it is easily adjustable, or if the
light is fixed stack something under the trays so you can lower them
gradually.

HTH,
Sue



"Jeffrey Barker" wrote in message

The whole thing about putting the light so close seems a bit
confusing. (I'd like to use just one or two lights for all of my
plants so I don't have to spend a fortune on lights.) The SUN is
pretty far away, so why is it such an issue to have the lights so
close to the plants? I know the answer is so they don't stretch out
and get spindly, but why does artificial light have that effect? I
know this must seem like a really idiotic question, but none of my
gardening friends seem to know the answer.

Jeffrey

Seed starting question
 

Jeffrey Barker wrote:

Ok. This is not a troll, and I really hope it doesn't seem that way.
I'm planning on getting a grow light for the first time this season,
after doing some mild indoor and outdoor gardening for a few years.

The whole thing about putting the light so close seems a bit
confusing. (I'd like to use just one or two lights for all of my
plants so I don't have to spend a fortune on lights.) The SUN is
pretty far away, so why is it such an issue to have the lights so
close to the plants? I know the answer is so they don't stretch out
and get spindly, but why does artificial light have that effect? I
know this must seem like a really idiotic question, but none of my
gardening friends seem to know the answer.
Jeffrey

The simple answer is that the sun gives off a *lot* more energy than a
fluorescent lamp. So to compensate, to have to place the fluorescents a
lot closer to the plants than you would the sun. People will probably quote
the "inverse square law" of light intensity to you, but it doesn't really
apply because the flourescent tubes do not resemble a point light source
(the sun *does*, however, from this distance); just the same, the light
intensity drops off dramatically as you increase the distance from the
source, even if it's not as bad as "energy decreases proportionally to the
distance squared". :-)

There are other issues as well, such as color spectrum, and photoperiodism,
but you don't need to know much about that -- just don't leave your lights
on 24 hours a day or you'll confuse some plants.

Best regards,
Bob

--
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Seed starting question
 

In article ,
Jeffrey Barker wrote:
"Tim B" wrote in message ...
Things you plant underground can't tell if there's light or not until
they're on top of the ground. Lettuce, planted on top of the ground,
needs light ... not massive amounts, but enough light to set off the process
that says, hey it's spring, let's grow. Once you have two true leaves,
everything you started will need light, preferably right on top of it 1-3
inches away so the plants don't go stretching toward the light.


Ok. This is not a troll, and I really hope it doesn't seem that way.
I'm planning on getting a grow light for the first time this season,
after doing some mild indoor and outdoor gardening for a few years.

The whole thing about putting the light so close seems a bit
confusing. (I'd like to use just one or two lights for all of my
plants so I don't have to spend a fortune on lights.) The SUN is
pretty far away, so why is it such an issue to have the lights so
close to the plants? I know the answer is so they don't stretch out
and get spindly, but why does artificial light have that effect? I
know this must seem like a really idiotic question, but none of my
gardening friends seem to know the answer.

Light falls off with distance from the source. How much depends
on particulars. If we approximate a fluorescent tube as a "line"
source of light (radiating equally from the line), then we can say
that the light intensity falls as 1/d (d = distance from the line source
to some point. In my "hot box" I cheat -- since this is not in a
window-sill, I simply cover the interior of the box with aluminum foil.
This essentially eliminates the 1/d falloff, so I can keep the lights
in the same place as the plants grow. If that isn't done, we would
expect that the light intensity will be about 12 times weaker at 1'
distance than at 1" distance (of course at 1" distance the line approximation
isn't particularly good).

The sun (from our perspective) is a point source; light intensity falls
off with 1/r^2 from a point source, considerably faster than from a
line source. However since we are approx 93*10^6 miles from the sun,
a 1 foot movement away from the sun (ignoring atmospheric absorption
or other attenuation, or reflections) will result in an attenuation of
only 1 part in about 2*10^26 (!). Yes, the effects that we've ignored
will have a much stronger effect than the one we were examining.

Hey, wasn't that fun?

-frank
--

Seed starting question
 

On 6 Mar 2003 09:52:57 -0800,
(Jeffrey Barker) wrote:

"Tim B" wrote in message ...
Things you plant underground can't tell if there's light or not until
they're on top of the ground. Lettuce, planted on top of the ground,
needs light ... not massive amounts, but enough light to set off the process
that says, hey it's spring, let's grow. Once you have two true leaves,
everything you started will need light, preferably right on top of it 1-3
inches away so the plants don't go stretching toward the light.


Ok. This is not a troll, and I really hope it doesn't seem that way.
I'm planning on getting a grow light for the first time this season,
after doing some mild indoor and outdoor gardening for a few years.

The whole thing about putting the light so close seems a bit
confusing. (I'd like to use just one or two lights for all of my
plants so I don't have to spend a fortune on lights.) The SUN is
pretty far away, so why is it such an issue to have the lights so
close to the plants? I know the answer is so they don't stretch out
and get spindly, but why does artificial light have that effect? I
know this must seem like a really idiotic question, but none of my
gardening friends seem to know the answer.

The sun is a much more POWERFUL light than any lamp you will
have in your home. Even by the time the sun's rays have
traveled all the way through space and through our
atmosphere, they are STILL much more powerful than any
artificial light you'd have in your home.

You will probably use fluorescent lights for your indoor
gardening and since many of them are 4' long, you can put a
lot of plants under one light fixture.

I believe the requirement for having the lights very close
to the plants is mainly for seedling plants: young plants
that you've just started from seed.

Many houseplants can be grown under lights that are not
nearly this close to them.

Pat
--
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