Starting Tomato Seed and Other Helpful Information: CMale

Louisville, KY

I am taking the liberty of posting this excellent article Carolyn posted at the TomatoMania web site several years ago. Perhaps it will provide some helpful information to you.

Subject: Starting Tomato Seeds
Date: 01/06/2000 11:33 AM Eastern Daylight Time
By: Carolyn Male

There's no one way to start seeds but there are a few things that MUST be
done or you tempt fate. Translate, you have lousy or dead seedlings. LOL

First, you MUST use artificial soilless mix. Regular potting soil has lots of
fungi in it and you increase the chances of your seedlings developing damping
off which is characterized by the young seedlings developing a narrowed stem
at the soil level and falling in DEAD. Rhizoctonia and other
genera of fungi are responsible for this disease. Using a Benomyl drench or
some folks say Chamomile tea, may deter it. So start with a good
artificial mix like Jiffy Mix (my favorite), or Pro-Mix or Peter's, etc.

Don't plant seeds in a container that you'll use to grow the plant to
maturity. You MUST transplant the seedlings at least once in order to get a
decent plant, as I'll explain later, so plant your seeds in any container you
like. I use Permanest seedling pans which are available all over the place
and they work very well. Now I sow many varieties and you may be sowing for
only a few. So you could use an egg carton and sow 4-5 seeds in a hole or a
margarine tub or a small Dixie cup or what ever.

You must completely wet the artificial mix by putting it in a plastic tub and
adding warm water. It will initially repel the water. Get in there and mix
with your hands until it's all moistened nicely. Then pack it into the
containers you're going to use. After I've packed into my Permanest trays I
moisten it again, pour off the excess water and let it sit exposed to the air
overnight. Tell you why I do that in a sec.

OK, now plant your seeds. Plant them about the same thickness as the
thickness of the seed, that is shallowly. And if the seeds are fresh plant
the seeds about 1/8 inch apart. If you goof and plant too many seeds you can
thin out the minute they come up. Sowing too thickly and not thinning leads
to spindly weak seedlings. You want each seedling to be quite separate. Sow
CHERRY TOMATO seed a week later because they grow so fast.

After you sow the seeds slip a plastic baggie over the container making sure
to leave an opening for air. You want to keep conditions moist so you DON'T
have to water the seeds yet you MUST allow for air circulation or risk
damping off and similar. I prop up the open end of the bag with one of my
plastic labels. Now set the pan/tub/whatever, on top of something where there
will be a tad of warmth. DO NOT PLACE under lights or you'll cook your
seedlings. If you use one of those kits with a plastic dome make sure the
dome is also propped up or you'll also cook the seeds, even better than with
just a baggie over them.Tomatoes do not need bottom warmth for germination,
as do most peppers, but they germinate faster that way. Place the pans on top
of the light fixtures or on top of your fridge or on top of your water
heater. Whatever. And when you see the first seedlings emerge, immediately
take off the baggie and place the tray/tub, whatever, under the lights or in
the light, etc.

If using lights you must keep the lights about two inches above the growing
seedlings. Sometimes an inch is fine. Yes, it means you'll have to move the
light fixtures often during early growth. It's hard to grow good seedlings
without strong light. If you use a windowsill be sure there are no drafts
because cold drafts and wet mix spell doom and death to the seedlings. And
you must remember to turn the container each day so light reaches all sides of
the plants.

OK, thin out the young ones if you sowed too thickly and you can do it just
by pinching them or use a small pair of scissors. At this point you should
not have watered you newly emerged seedlings because there was plenty of
moisture in the mix covered by the baggie.

Added this after finishing the whole post. If you use lights do so with a
timer. Leave them on for 14-16 hours per day and NEVER at night. The
metabolism of plants is such that they need a dark period to make energy
products to grow.

In a couple of days you'll see the mix drying out and you can water very
gently. The first little green things that emerge are NOT leaves, they are
called cotyledons. They are followed by the first set of leaves and then the
second set of leaves at which point you MUST transplant the seedlings to
another conatainer as described below.

Occasionally the seed coat doesn't come off one of the germinated seeds and
if you don't remove it the plant will die. Surgery is called for. LOL Moisten
a cotton ball and hold it to the seed coat for a few minutes. Then gently
grasp the seed coat with your fingers and it should pop off. If it doesn't,
you lose. Or shall we say the plant loses. Sure , I've snapped off the whole
tops of the plants sometimes and then had a funeral service, but that's
why you always plant a few more seeds than you need. LOL

Now, have I said anything about fertilizing? NO NO NO. Do NOT fertilize. You
risk burning the delicate rootlets and the seedlings don't need it anyway.
They have the endosperm rich contents of the seed to grow on. Water your
seedlings as they need it, but sparingly, and when the second set of leaves
emerge it's time to transplant. The seedlings will usually be about two
inches high at this point.Experienced folks transplant at even a younger
plant age.And if you feel you MUST fertilize please use a very dilute

OK, now time to transplant. I use commercial trays with plastic cell type
liners. Each tray has eight 4 cell units. Each cell is about1/1/2 inches in
diameter and about two inches deep. There are then 32 cells per standard
nursery tray that isabout22 by 11 inches. Don't go smaller than that on cell
sizes.The seedlings will be grwon to maturity in these cells and I'll have
beautiful, lovely stocky plants. Yes I will. LOL. It's best if you use the
same soiless mix at this point, or if you have lots of plants you can use
perlite and/or vermiculite and add one part of the latter to one part seed
starting mix.. So rewet your unused mix or mix up a new batch and pack the
cells with mix. If you want to
use small individual pots at this point that's also just fine. But don't use,
IMHO, a huge pot, like over three inches, or so. You don't want to grow huge
transplants to put in the garden. And you want the major initial growth of
the plant to be in the garden or container and not in a pot or cell.You want
a plant about 9-12 inches tall. That's all. OK, so to transplant. Make sure
the mix with the seedlings is moist. Delicately grasp a seedling by the
LEAVES and, whoops, you would have poked a hole in your new container with
mix before you pick up the seedling.
Make that hole with a pencil. Works fine. And you're going to sink that
seedling ALL THE WAY down so only the little leaves are above the soil line.
That's important. Very inportant. Tomatoes form roots wherever the stems make
contact with soil so you want to sink those plants way down. And then you
don't have exposed stems to flop over either. LOL Now water in the newly
transplanted seedlings.

OK, why is it so important to transplant? Because it shocks the plant and
retards foliage grwoth so that root grwoth can occur. If you don't do it you
get huge leggy stupid seedlings that flop all over the place and are a
disgrace to the genus Lycopersicon. That's why. LOL

Put your transplants back under the lights keeping the lights no more than
two inches, or so, from the leaves. I didn't mention it above, but your
lights should be on a timer and be on for about 14-16 hours a day. They need
a dark period for metabolism, so don't run the lights at night. Put your
transplants back on the windowsill if not using lights and keep rotating the
containers each day so they get even light.

Tomato plants develop best when grown at cool temps. Commercial growers will
usually have one greenhouse set at about 55-60 F degrees. If you can
duplicate that you're going to get a better plant. Warmth is needed for
germination and early seedling growth but once you transplant you want cool
conditions for optimum plant development. If you can't, you can't. So Don't
worry. But don't compound the problem by trying to fertilize your
transplants. DON't
Fertilize. let the plants develop naturally, which they will. Don't risk
burning the rootlets. When the plants are about 4-5 inches high if you want
to fertilize with dilute something, go ahead. I suggest fertilizing with
water. Bit of a joke there. But I assure you it's for your peace of mind, not
the plant's benefit. Fertilizer at this point can cause too rapid growth and
weak stems, so please don't do it. PLease? LOL You aren't going to fertilize
those plants until they're transplanted out in the garden, OK????????? And
we'll get to that whole business later, not in this post.

You keep growing your plants until they get to be maybe about 10 inches high
and it should be close to when you want to transplant them outside.If you
want to run a fan near your growing plants that's fine also; good for air
circulation. And if you want to run your hands or a ruler over the foliage a
couple times a day that's fine too. The plants respond to touch, called
thigmotropism,and that is sometimes reflected in even better growth.

Next you must harden off the seedlings. That means putting them outside for a
few hours each day , initially in a shaded spot, and then increasing exposure
to the sun as the days pass. Protect from harsh winds and bring the plants
inside if cool weather appears, etc. you must toughen them up for the big
cool cruel world out there. And withhold water as best you can. Starve them
and don't water them until they start to wilt, then water a bit. Got to
toughen them up.

And at this point REMOVE every single blossom on the plant, if there are any.
The earliest growth of a tomato plant must be devoted to vegetative grwoth of
leaves, stems and roots, not a sexual cycle of reproduction and setting
fruit, etc. So get all those blossoms off the plants. Blossoms that develop
once the plants are out in the garden are fine to leave on the plant.

When the weather seems settled it's OK to put out the plants. Remove the
bottom leaves of the plant that have turned yellow. It's natural that they
would have turned yellow and most of the time those yellow leaves will fall
off naturally. If not, you take them off. Now set the plant into the hole so
that the soil level is right up to the bottom green leaves. It is important,
again, to set the plants deeply. After transplanting to the garden water
them in.

NO NO NO, do NOT use dilute fertilizer at this point regardless of what
you've read, etc. You've got new roots meeting new soil and you want to let
the root system develop with out any interference. And you DON"t put anything
into that hole. No Epsom Salts, no dead fish, no matchheads, etc. The only
thing going into that hole should be the plant. Period.

OK, we've got the plants out there and you've put them where they'll recieve
maximum sun and hopefully placed them where the AM sun will burn off the
morning dew. That's important in terms of foliage diseses.

We haven't talked about spacing of plants because that means talking about
HOW you're going to grow them. That is, staking, caging, sprawling,
trellising, etc.

And that's an area we can explore separately. Plenty of time.

The above is a guide based on my own experiences of trying a variety of
methods.I'm sure many of you have come up with methods that are different
that might work better for you. The point is to experiment and see what works
for you with your space limitations,light limitations, etc.

Seeds should be started 6-8 weeks before the last average frost date, for
most folks. In the warmer zones that's not an issue. And we've already
discussed planting two crops a year in zones 9 and 10. Cherry tomatoes should
be seeded a week after the others because they grow more rapidly..

At least the above can serve as a guidleline for folks new to planting tomato

No doubt I've forgotten something in the above, maybe not, but we can work
thru it together.

Good luck and skill. You all can do it.

NY, zone 4/5

First, I admit I'm lazy when it comes to doing e-mails to any message
board for the purpose of giving links. So please excuse me on that

To find out how to do TSP treatments just go to and enter
the words....TSP treatment of tomato seeds. The first link that pops
up is Tom Wagner's and he gives you his method. But please remember,
as he also states, that he's using a single fruit most of the time as
part of his breeding programs. So fermentation is not a viable
alternative for him.

And there are other links there also with more detailed specific

I'm really quite surprised that use of TSP ( trisodium phosphate) is
approved by Organic Gardening standards, but there are also other
contradictions that I see, but we won't discuss them here. LOL

Instead of using saltpetre as I used to suggest for waking up seeds,
I would try just an overnight plain water soak first, or going one
step further, use of dilute Miracle Gro or similar. It's the nitrate ion
concentration that is the important ingredient.

I never pretreat seeds unless I have a very rare variety for which
there is no other source of seed available. I don't treat to enhance
germination, just when there is no germination at all because the
seeds are too old.

But I'll repeat here, I cannot and will not recommend TSP treatment
of any seeds for home gardeners because of the caustic nature of TSP
( trisodium phosphate). Pets and kids are important. If an adult
works with it alone with gloves and other safety stuff, then maybe
OK. But why use it when there are , I think, more reasonable
alternatives. For commercial places, yes, it's less bothersome than
other methods, but few home growers are commercial in that sense of
the word.

As regards fermentation, in all the years I've been doing it the only
time I get germination of seeds in the mix is when I've let the
fermention go too far. I've never had germination of seeds before
that. Are you making sure that you have plenty of liquid in the mix?
With certain varieties I don't get much juice so I always add a tad
of water.

I also find that the gold/red bicolors which have very soft flesh are
more prone to have germninated seeds inside the ripe fruits. So for
them I usually use fruits that are not definitely not overripe, or
usually I use fruits that are slightly underripe.

Hope the above helps.


Salem, NY(Zone 4b)


I post that same article wherever I go and have posted it here as well. LOL

About the only thing I'd change in that version, and I di dn't read it all the way th rough, is that most f olks now use starter mix with some micr onutrients in it and if so, no add it ional fertilizer is needed until a we kk o r so after the ini tial transplant.

When I wrote that article, man y years ago, I didn't use any fer tilizer whatsoever and used artificial mix with no micronutrients. I would use some very dilute stuff a few weeks after transplanting.

The whole point with seedlings is to grow them cool and slowly to get the best transplan ts and too much fertiizer at the seedling st age is no t good.

Same goes for fertiizing in the main growing season.

Too m uch N can inhibit plants from going into the sexual cycle of blossom for mat ion and fr uit set by keeping them in the vegetative phase of ne w stem and root and leaf growth. It also can predispose to BER sinve too much N is a stress to the pla nt.


Louisville, KY

Carolyn, I think it is very basic and helpful information. We have a number of new folks here and others who might find the article useful while planning their gardens. Thank You!

Lafayette, NJ(Zone 6a)

Thank you Carolyn and Gary. Great information, as usual.

Nashville, TN(Zone 6b)

Awesome information! I'm so glad we have such a wonderful Tomato Guru here!

Pembroke Pines, FL(Zone 10a)

That is the best seed starting advice ever written ! I used it and had no more leggy seedlings and no more damp-off. I thanked you once before Carolyn but "Thank You Again."

Louisville, KY(Zone 6a)

I don't know if my tomatoes will ever look as good as yours probably look. Must be my Pleasure Ridge Park growing methods. I'll try yours.

Ijamsville, MD(Zone 6b)

Carolyn - You said: "...pour off the excess water and let it sit exposed to the air
overnight. Tell you why I do that in a sec"

Maybe I missed it but could you please explain why to do this? If I germinate in a 72 cell tray, what size should I transplant up to? never mind! I just reread and it say a 32 cell tray.

We are going to start our seeds this week! Wish me luck:)

Thanks -Kim

Salem, NY(Zone 4b)


I don't sow seeds in 32 cell trays.

I used to use 8X 8 inch Permanest pans, that we talked abou t in aother thread here, and i t's with those that I saturate the mix and then pour off t he excelss water. That's just to be sure the mix is well hydr ated and I do n't have to water seedlings until the plastic cover is off and they are under t h elights, as I grew them then.

I swritched quite a few year s ago to using 20 row professional seed starting inserts and I do t he same thing with those.

I transplant from the 20 row planters to the plastice 4 paks, 8 to a tray, 3 2 cells per standard nursery tray.

I never sow seeds in cells or anything that large b/c I want to be able to transplant from a seed start ing tray TO platic cells.

Carolyn, not editing, sorry

Frederick, MD(Zone 6b)

Kim, don't use your 72 cell tray for germinating, use something like a plastic takeout container with holes poked in the bottom for drainage (clear lid). We will put your 72 cell tray to better use! :-)

Ijamsville, MD(Zone 6b)

Thanks Carolyn - I get it now, in my head of course. We will see about real application!

Yes, Jill. I will give it to you and you will give it back to me full of seedlings?

Richmond Hill, GA(Zone 8b)

Carolyn writes: "Too m uch N can inhibit plants from going into the sexual cycle of blossom formation and fruit set by keeping them in the vegetative phase of new stem and root and leaf growth. It also can predispose to BER sinve too much N is a stress to the plant."

I've been so busy working because tax season is upon me that it's all I can do to get out to the greenhouse to water my tomato plants. Many of them have blooms! I guess I should take them off before I plant them. Now that is going to hurt! ;-)

Victorville, CA

Ewww! More micro surgery.

Pleasant Grove, UT(Zone 6b)

Man... I hate admitting my mistakes here as I have too much pride I guess. I got some more bad advice and I gave my seedlings (first set of true leaves, second set starting) some half strength miracle grow and I am seeing some yellowed leaves and some leaves actually are getting a little browning on the edges. I feel stupid so I am trying to correct this by filling the drip tray under my cell packs with fresh water. I am planning to leave them in the fresh water overnight and then throw out that water so I will have rinsed out the soil a little... Am I heading the right direction?


Okeechobee, FL(Zone 10a)

I over did alfalfa tea on several things, causing some yellow leaves. I am coming behind and applying 1 gal water with 1/2 cup hydrogen peroxide to ouside plants. Good luck.

Victorville, CA

My second set of leaves were starting to look a little yellow so I gave them some Miracle Grow. One leaf got some on it and by late afternoon withered almost off. The rest look ok.

Pembroke Pines, FL(Zone 10a)

Why you must fertilize at such an early stage is beyond me ? The seed contains a built in supply of fertilizer. You are probably giving them to much water or depriving them of light and ventilation.

Pleasant Grove, UT(Zone 6b)

With me it was my thought that I was overwatering as nothing had moved and I had low germ rates. Pulled off the humidomes, watered a lot more and they started doing lots better, I have overdriven my 4 foot flourescent light fixtures so I doubt that is the reason and I am using steril Jiffy Mix in normal flats. The only thing I changed recently is to add dilute water soluable. It is done... I do not remember who even told me to do it but they were referring to the entire garden (starts) and it has really done amaizing things for my lettuce (high N consumers). I did not remember this article (though I read it before. Now that I was stupid and got myself in a jam I just need to get it repaired as best I can.


Pembroke Pines, FL(Zone 10a)

I touch the soil with a dry finger. If soil sticks to my finger, I water sparingly, If no or very little soil, I leave well enough alone. It works for me !

Pleasant Grove, UT(Zone 6b)

Here is a picture...

Thumbnail by Drew_N_Corinn
Salem, NY(Zone 4b)


As you now know half strength MG was bad b/c it can burn the delicate roots and also cause too rapid growth for those that can stand it.

I know you're trying to flush it out with that standing water, but I do think that could be making the problem worse by drowning the plants in that much standing water for that long. Doing that deprives the plant of oxygen uptake thru the roots and if the roots are damaged already, well, I think you see the problem.

If it were me I'd water only when they start wilting right now in order to allow for new root growth if at all possible at this point and looking at your photo I think conditions for most of them can reverse if you keep them on the dry side.


Pembroke Pines, FL(Zone 10a)

I would also transplant them into fresh soil and larger containers. Also snip the cotyledons off the plant and bury your plant up to the true leaves. This I also learned from Carolyn. It works for I got the most healthiest plants in my life with trunks as thick as my finger at 10-12" high.

Richmond Hill, GA(Zone 8b)

I think your tomato babies look great, Drew! Great job. :-) Just water when they dry out as Carolyn suggests. :-)


Shenandoah Valley, VA(Zone 6b)

Someone else asked about this but as I don't see an answer, I'll ask again...

"After I've packed into my Permanest trays I moisten it again, pour off the excess water and let it sit exposed to the air overnight. Tell you why I do that in a sec."

Is this to reduce the risk of damping off when you do plant? To let the mix settle? Am I a bonehead?

Ijamsville, MD(Zone 6b)

Hi Zeppy - I can't answer the last one! Actually I can't answer any of them - I had asked before, I am glad you brought it up again. Maybe evenly moist?

Inquiring minds want to know!

Pembroke Pines, FL(Zone 10a)

Zeppy --- Yes. Also makes the mix more workable otherwise you would be working with a muddy mixture and your seeds may rot before they sprout.

Salem, NY(Zone 4b)

I do what I do b/c I want the mix entirely saturated, yet workable, b/c I don't want to have to water newly sown seeds. Too often watering can cause seeds to jump out of position and when one is growing lots of varieties that's a real no no.

So I wet the mix competely so it actually has standing water, leave it over nmight, pour off the excess and go to it. I then place a plastic baggie over the pan with one end propped open so as to ensure air flow so damping off doesnt' occur, although it seldom does if one uses soiless mix, and more particularly the Jiffy Mix, Pro Mix or Fafard mixes that I prefer.

Each of you has to come up with doing things the way that works best for you. What I described works best for me.

Carolyn, who should also mention again that I do not read all threads here and even if I've posted within a thread and feel I've answered someones question, I often don't continue with that thread. So have said a cou ple of times you'll have to call stuff to my attention if I miss a question directed towards me, as you've done here. So thanks for that.

Everson, WA(Zone 8a)

Just thought some new people may find this helpfull to read. Ernie

OC, CA & Twin Lakes , IA(Zone 4b)

Thanks Ernie,
I love re-reading this thread!

Louisville, KY

Ernie, How deep did you have to dig to find this old post? lol
I remember when Carolyn was either having surgery or recovering, I posted this for the benefit of those who might be new or who needed a refresher on starting Tomato seed. Thanks for finding it. It Is A Classic Article!

Paris, TN(Zone 6b)

Thanks for bumping this up for us newbies!


Greensboro, NC(Zone 7a)

I try tomatoes almost every year...I say try:LOL: Haven't had booming success but I have such great memories/experiences of the tomato gardens my parents had that I can't stop. This is on my watched topic list so I can always find it and be up on any new info. Maybe this will be my year of the tomato:LOL:

Mesilla Park, NM

This post has been really helpful to me. This is the first time I try tomato seed. After reading several posts yesterday, I think that I made a big mistake. I sowed 2 seeds to each cell in those 72 cell pack trays. Then, put them on a heatmat with no lighting and no dome last night.

After reading this post, it gave me some concern, are we NOT supposed to use the 72 cell packs because they are too big, or because they are plastic or are the 72 cell packs only to be used to transplant up..

Should I start over? Thanks for any help.

Westbrook, CT(Zone 6a)

No reason to start over. The cell packs shouldn't seem any different than plain trays to the seed as far as I can tell, and keep the plants separated. You are going to transplant the seedlings to larger cells pretty soon anyway. Be sure to put them under lights and off the heat as soon as they sprout. I presume that if both seeds in a cell sprout, you will snip off the runt to avoid competition. I usually only put one seed per cell to avoid fussing with them unless the seed is several years old.

Mesilla Park, NM

Thank you very much DonShire.

Will do as you say.. I did have some seeds from 1976 (yellow pear shape) that I am trying, just for the heck of it. It is so interesting, they were 39cents at that the rest are all new seeds.

Thanks again.

Salem, NY(Zone 4b)

I did have some seeds from 1976 (yellow pear shape) that I am trying, just for the heck of it. It is so interesting, they were 39cents at that the rest are all new seeds.


Perhaps best to soak the seeds you're going to sow o/n in water with a pinch of blue stuff, as in MG or Peter's or a few drops of liquid seaweed or fish emulsion before sowing them.

Older seeds are very dessicated and want to get hydrated. Be sure to stir the seeds until they sink.

The additives i suggested increase the nitrate concnetration which is known to be importatn in seed germination.

But knowing Yellow Pear as I do, the seeds might well come up, or a few of them, without any treatment at all. LOL


Mesilla Park, NM

Thank you Carolyn,
I do have fish emulsion and did not know we could use that to soak the seeds.. that's great to know. I've been using peroxide and superthrive to soak seeds (mostly morning glory seed), also have some kelp.

I didnt' soak the older seeds but will try a couple more, they do look very dehydrated come to think of it. This is a first for me with tomatoes. Also ordered several black varieties from SeedSavers and one other place, so this is my practice

I really enjoyed your article too. Very helpful to me. Thank you.

Salem, NY(Zone 4b)

I do have fish emulsion and did not know we could use that to soak the seeds.. that's great to know. I've been using peroxide and superthrive to soak seeds (mostly morning glory seed), also have some kelp.


You don't want to soak the seeds in the normally diluted fish stuff or seaweed stuff, you want to soak the seeds in water to which you add just a few drops of those diluted preps.

The peroxide is OK to help disinfect the seed surface of some of the tomato pathogens that can be seedborne that cling to it, but I rely more on adquate fermentation to do that. (smile) But that still leaves the pathogens that are in the endosperm of the seed, mainly certain viruses and certain bacterial tomato pathogens. Can't worry about everything at one time though. LOL


OC, CA & Twin Lakes , IA(Zone 4b)

Thanks for the good tips, Carolyn

Cincinnati (Anderson, OH(Zone 6a)

Thanks for posting Carolyn's very informative article about seed starting for tomatoes!

I am sort of a newbie with seed starting and something of a klutz so I was hoping the Wintersowing method of seed starting might work with Tomatoes? thought perhaps with the 'cold' treatments suggested sowing outdoors from the git go might be an ideal and easy way to get the seeds germinated and healthy seedlings up and growing well...

Does anyone have any idea on whether WS would work in Zone 6--maybe with early or mid-season varieties? And has anyone tried it?

I asked on another thread but didn't get much response so I thought I would try here. Carolyn?)

Thanks so much. t.

p.s. Here's the WS forum link FYI

and another link with good descriptions of WS methods

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