So obviously it should take less time for an existing 12 inch plant to produce and mature than an ungerminated seed of the same variety......

Not really. What is listed on seed packets is DTM - days to maturity - meaning fruit ripe to pick. And DTM is computed from the time of the final transplanting to its growing place. So the DTM for a larger plant that still has to be transplanted to the garden will be approximately the same as that of a small plant that has to be transplanted.

That is one reason why using smaller transplants is recommended. Not only do they tolerate the transplanting process better, recover quicker, and are less likely to be root bound than large plants but they will quickly catch up and even pass the larger older plant once transplanted.

That said, what is really important to understand is that DTM is just a very loose and general guideline - an educated guess if you will. This is because it can be affected by so many other variables - garden zone, growing conditions, environment, container or in-ground, sun exposure, weather, nutrients, watering, pests, soil type, etc. etc.

So it's better to think of it as an 80 DTM plant, once planted in the garden and IF all else goes well and the weather cooperates will mature to ripe fruit stage in approx. 75-95 days.

Dave

Dave brings up a good point regarding DTM. An educated guess. Guess being the keyword. I have seen smaller transplants catch up to bigger plants with my own eyes. I have seen bigger plants take off and the smaller ones never catch up. In the end, it really does not matter much.
Dave also hits the nail on the head regarding conditions. Weather and the amount of air in the very spot where you plant, which is changed hour by hour by weather,or nematodes(good or usually bad), is usually the judge.

It's so easy following a Dave post. Dude knows what he is talking about.

Take care,
Travis

DTM is also designed for farmers who try to follow a cost effective schedule of getting seedlings in the ground on the last frost date when the seedlings are 6"-10" tall. My seedlings are about the size on that date, but I usually get them in later and larger, and usually hit near to the est DTM. High temps will speed things up, cool temps slow them down. I have seen regional seed companies (Pacific Nnorthwest) tack on extra days when describing the varieties they sell.

I purchased some really nice looking, 12 -18" Cherokee Purple plants this year to replace some seedlings i had lost. These four plants were placed at the same time as my tiny, tiny seedlings with only two to three true leaves. There was no difference in dates when I started getting fruits from these plants. In fact, after a month, I couldn't tell them apart!

There are two stages of importance regarding tomato
plants. One is the root setting, and the other is the flowering stage. One of the most important plants in the world. Also one the strongest.

Take care,
Travis

I beg to differ. In my experience a big plant will produce tomatoes before a small plant of the same variety, planted under the same growing conditions and on the same date.
People coming to see my garden marvel at why my plants are so much bigger and healthier looking than theirs. The reason is I sell tomato plants, and usually start about ten of each variety. I keep the largest, most vigorous plant for my own garden, and sell the rest. Unless you sell plants, it would be cost prohibitive to grow ten of each variety and only plant the one best.

In my experience a big plant will produce tomatoes before a small plant of the same variety, planted under the same growing conditions and on the same date.

I don't think that anyone would dispute that California benefits from unique growing conditions that the rest of us don't have. But if you are selling all the smaller plants, planting only the largest and most vigorous, then how can you compare?

I too grow for plant sales and while I hold back sufficient plants for my gardens I don't do any selective choosing for size or vigor. It is more like a mixed bag of "left-overs". So even in my highly challenged growing conditions I can easily compare performance between the different sized/age/variety transplants.

Dave

Sorry to resurrect this thread, but I'm interested in what Dave mentioned about smaller transplants catching up with, and even passing, larger ones.

We have such a miserably short tomato season here in the Florida panhandle, that I've always bought the large plants from Lowe's/HD about late February. I'll carry them inside and out as the weather and temperature dictate, and by the end of March or beginning of April, I put them in my tubs when the danger of frost is over. By that time, they're 16-18" tall, and some are even flowering. I remove the lower sets of leaves, plant deep, and in 70-80 days I'm picking the first tomatoes. The season is over in another 30 days. I grow indeterminates, BTW.

Last year, I experimented with Big Beef hybrid Mighty 'Matos. They arrived small and wilted, and they never caught up with the others, and the yield was low. Perhaps it had to do with the stress during shipping, but I would've thought that the "superior" rootstock would've overcome that. Live and learn, I guess. Is it possible that root stress in tomato seedlings will plague the plant through maturity?

So, this year I decided to experiment with growing from seed. My seedlings are 20-30 days past germination, and still stuck in the cotyledon stage. I have them in a south-facing window, underneath a high-output, wide-spectrum CFL. I can't do anything about the temperature, but daytime is about 72F, and nighttime about 68F. I'm particularly surprised by the SunGolds -- some of the other varieties have tiny true leaves appearing, but the SGs were the first to germinate, and they show nothing.

Having not done it this way before, and given that they seem stalled, I'm concerned that I may not have decent-sized plants when I need them. (My only experience growing small plants alongside large was last season with the Mighty 'Matos.) Based upon what I'm observing, I'd have to guess that the tomatoes sold by big box stores are started the first of December or so. But if smaller transplants are better, maybe it will all work out in approximately the same time frame as I'm used to?

Appreciate your thoughts!

-Bruce

My seedlings are 20-30 days past germination, and still stuck in the cotyledon stage.

Then something is seriously wrong. 30 days after germination (not planting the seeds) tomato plants will normally have 2-3 sets of true leaves and be 4-6" tall. Air temps are ok but would need all the details on growing methods, watering, and soil to begin to know what.

Is it possible that root stress in tomato seedlings will plague the plant through maturity?

Yes but a compromised circulatory system - wilted symptom - is even more of a problem. I wouldn't compare results.based on that plant.

and by the end of March or beginning of April, I put them in my tubs when the danger of frost is over.

That timing bothers me based on what I have read from other panhandle growers. It is late. Are you in some sort of microclimate pocket compared to the rest of the area like say a low valley where frost would be so late? Have you ever tried planting earlier than that? Even if you have to cover for the rare late frost?

Dave

Dave

Hi Dave -- thanks for your response.

I'm using about a 2:1:1 mix, and utilize a "compot" - type method where I'll space 4-5 seeds in a 5" or 6" plastic pot, then will separate later. We are extremely dry inside our home, and I'm probably watering lightly every other day with a hand sprayer. Leaves are dry in a few minutes. I keep the soil at a "damp, clumpable" stage. Our heat is central air, so there is air circulation contributing to the drying rate of the soil. There is no wilting, however, and leaf color is good. They are 1" to 1-1/4" tall.

I really don't know what else I could change or adjust, and I'm pretty discouraged when you say they should be 4-6" tall!! The only thing I can think of is the light hours. I read where some folks keep the lights on 18 hours per day, but I don't do that. One thing that has happened this winter for us is the lack of sunlight. In the past 60 days, I doubt if we've had seven days of full sunshine, so, most of the light the seedlings have received is from the CFL. It's an expensive lamp, so I only run it eight hours per day, from 7am until 3pm, expecting that by the time the sun swings around to that window, that picks up the slack for the rest of the afternoon. That said, I'm not seeing any significant response from the plants in terms of phototropism. They lean somewhat towards the window. A couple of the seedlings I've put very close to the bulb, and others a foot away, with no difference in growth.

One year I put my plants in the tubs the last week of March, and we got caught with a frost about ten days later. It was a major pain to cover and seal the tubs adequately! Usually those late frosts don't happen, but it's still possible to have them until the end of March. The problem is how difficult it is to cover and seal the tubs -- much easier to protect if they were in the ground, but much of this area has bacterial wilt, and the only way to grow tomatoes is in tubs.

I grow citrus and other plants that need cold protection, and from a purely practical standpoint, that's another reason I avoid putting the tomatoes out. There's just too much for me to do when it gets cold.

We are 16 miles from the Gulf coast, but a half-zone colder. When I check the weather forecasts here (north of Panama City), I actually check Crestview and Marianna which are further north, because those forecasts are more likely for us. Weather forecasts are becoming more and more unreliable these days, as there is more and more asphalt and concrete influencing the "official" reporting stations. This winter has been the worst yet in terms of accuracy. It either is much colder than the forecast, warmer when the prediction is freeze, heavy rain when no rain or light rain is predicted, etc.

-Bruce

I'm using about a 2:1:1 mix, and utilize a "compot" - type method where I'll space 4-5 seeds in a 5" or 6" plastic pot, then will separate later. We are extremely dry inside our home, and I'm probably watering lightly every other day with a hand sprayer. Leaves are dry in a few minutes.

"Compot"? 2:1:1 mix of what? Germinating seeds in that large a pot is very problematic. it is likely 6 or so inches deep, correct? Far too much volume of both soil and water for young seedlings. Shallow containers with drain holes, no more than 1 1/2-2" deep max. is much better.

That volume can easily lead to poor root development in young seedlings as they are overwhelmed by the soil moisture levels. You get stunted, shallow roots.

And with watering qod the problems are only compounded. Never get the leaves wet. No misting - it is for germination only, not growth and encourages fungus development.

I recommend each of those seedlings be transplanted into its own shallow container with most all of the stem buried in the soil right up to just below the cotyledons. And with a quality potting mix. Something that is already pH balanced. Then bottom watering only and only when the soil knuckle deep is dry.

Within a few days you should see a substantial change in growth and development. And light, MUCH more light. Not necessarily longer, just more. Window light this time of year is of little to no benefit to seedlings unless you are in the southern hemi. It lacks normal intensity and lacks the full spectrum. You don't mention lumen rating of your CFL but most of the time 1 of them is not sufficient.

Lots of good FAQs and discussions about this over on the Growing from Seed forum.

Hope this helps.

Dave

Here is a link that might be useful: FAQ - How to grow tomatoes from seed

Thanks again, Dave. The mix is fine pine bark, organic content (peat, manure), and perlite. The pots are "azalea" type generally used for orchids, and have large drainage holes around the bottom. (Using what I have available to me.) I've checked the moisture enough so I have a good feel for what's required in terms of watering.

I said I use a mister, but only because it's the most convenient method for reaching under the hood. The soil gets a good drenching when I use it, but never enough to run out the bottom of the pot.

I don't know the lumens of the CFL, but it's substantial. It's 125 watts, and is so bright it hurts to look directly at it. As I mentioned, it's under a hood, and I have a few of my orchids on the bench as well.

Thanks so much for your suggestions, and the link.

-Bruce

First: DTM is just a ball park statistical number, just like Last Frost, First Frost. The seeds seller indicate a more optomistic numbers, based on where they experiment(Like in south Alabama).

Seedling Mix:
I am new to this myself but this year I have been doing fine. I use a mixture of PINE FINE, PERLITE VERMICULITE, and regular POTTING SOIL. i have been experimenting on this since mid November and some of my peepers are fruiting . Another thing is that I Bottom-water and add 1/3 strength fertilizer. I let them get real thirsty and near dry between watering. This keeps the top dry and free of mold , insects and disease. . I also have a small CPU/computer fan running.

I had an instance of some insect (gnotes ?) and get rid of it by camomile tea spray.

I think there isn't a cook book method. Everybody has to experiment and learn.

Of course there isn't a "cook book method". There are however well-researched, well-documented, and commonly used methods that have not only stood the test of time and experience but been proven to be most effective by people who grow 1000's of tomato transplants annually.

Bruce - manure is commonly considered harmful for germination and young seedlings. It can easily harm young roots. Azalea pots unless filled with only a couple of inches of soil are still to deep for young seedlings. Lighting is crucial. Even in the greenhouse we have to use supplemental lighting this time of year and out halides put out much more than any CFL can. :)

As one who has been in the business of growing tomato transplants for years, and given your results so far, I can only encourage you to re-evaluate the methods you are using and change them.

Why not take the time to visit a local nursery that grows transplants and ask questions and explore their methods.

Dave

Thanks again for your thoughts, Dave. The manure in my mix is several years old, and well-composted -- actually taken from my tomato tubs. The pine bark fines I just added before planting the seed. (The seed is perhaps 4-5 years old -- and I didn't expect a high germ rate.)

It would be great to visit a nursery that grows seedlings...except there isn't such an animal around here! I would much prefer to buy heirloom plants, but the only way to get them is through the mail, and they wouldn't arrive early enough for my season.

-Bruce

So obviously it should take less time for an existing 12 inch plant to produce and mature than an ungerminated seed of the same variety......
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
I believe it does and should make a difference. Otherwise it would be ridiculous trying to start early and grow a better seedling. It is just raising your plant indoors for a longer time and bring it out when the outdoors conditions are right. A plant that has already small fruits on it should produce a ripe fruit in much shorter time than of the counter part 6" seedling.

JMO

A plant that has already small fruits on it should produce a ripe fruit in much shorter time than of the counter part 6" seedling.

Yes it does sound like you'd have that advantage in theory anyway. But in actual practice what usually happens is either the larger transplant doesn't survive the stress of transplanting process, especially when it is already rootbound, or it aborts the small fruits so that it can survive the transplanting process.

And those large transplants that do survive and do focus on ripening those existing fruit often never develop the healthy root structure needed to support the plant throughout the season since their energy has been focused on those fruit.

Meanwhile the smaller, unstressed plant has tolerated the transplanting well, triggered its fibrous root development, and focused on healthy system development rather than trying to adjust and ripen those early small fruit.

Dave

My experience:
I grow now from my own dried seeds. I've bought seeds and grown them from from scratch. I've bought seedlings. I've bought mature plants 18in. tall. Once I moved into a place, and for whatever reason, tomato vines were growing up the fence. Point is, I think I've seen the gamete.
The plants growth, the time it takes the fruits to ripen: it all depends on the conditions. It's totally up to favor.
This year, our weather has been mild. No more than 2 or 3 days over 90F, with breaks in the low 80s-mid 70s. I staggered seeding and planting by 4 weeks, and all of my plants are roughly the same size, save the very latest. But give them a week, and I bet they will keep up.
The growth of the fruit depends on the nutrients in the soil, and the sun exposure. Pruning and fertilizing. Never fertilize directly on roots. It can rot the roots and make for tiny little tasteless fruits. The fruits need some sun, but not so much that it's wrinkling them at all. I've even gone to putting up light shade nets if some leaves get damaged by insects. This year, I've been pruning so much I feel like I'm doing something wrong. But they do need it. Lack of light makes for mealy fruit that lacks nutrients.
"There is no place for impatience in a garden".

In Montana, most of my tomatoes (started by me) become fully ripened in August. However, tomatoes I started this year on 3-25 (and transplanted to 1-gallon pots at some point) ripened in July (early July through the first 3/4 of the month). NOTE: Those started on 3-25 (and transplanted into 5-GALLON pots) ripened earlier--in late June. Transplanting for both sets was the first week of June. (BTW, I have never seen any stress caused by transplanting, no matter the size of my plant/pot. My tomato plants really take off after they go in the ground.) Those started later, on 4-10, have NOT RIPENED as of August 1. ALL of my tomato plants are loaded with tomatoes, ripe or not. This data doesn't give us the same info as comparing the planting of 6" plants vs. 12" ones would, but it shows that starting early CAN produce earlier tomatoes, especially, IMO, if bigger pots are used, as needed. I did, btw, plant some tomatoes in 4" pots (that were very tall and should have been transplanted into 1-gallon pots) at the same time that I planted the ones in 1-gallon pots in the ground. Those made a good effort in catching up, in size at least, but they were just flowering when others had lots of fruit on the vines. Were any of my plants root bound, particularly the ones in 4" pots? Not that I recall. In fact, I need to learn how to produce more root and less growing top because my tomatoes get too tall before transplanting outside (I have them on a southern-facing, plastic-covered back porch WITH a roof, so they don't get full sun, by any means, which is the main reason they get so tall). I like starting plants earlier than recommended, especially since I moved to this colder climate. I believe, if the roots are given plenty of room, this method can produce healthy plants that produce earlier, just like with flowers that you want to bloom earlier. But beware--it's a lot of work to bring all those plants in big pots inside every time the temp looks like it's going to dip below 45 degrees F at night!

Cheryl - what varieties are you growing? My tomaotes started 3/29 (indeterminates) and transplanted June 3- 18 have fruit but nowhere near ripening (even the Bloody Butcher and Morvasky Div, though those were transplanted at the tail end of that timeframe, the late-season things like Brandywine went in first). The Grandma Marys that went in on June 4 are starting to lighten to a yellow-green but not blushing yet, the Cosmonaut Volkov are full sized but still more green than yellow, and the Black Krim (first to set fruit) have developed dark-streaked green shoulders but the blossom ends are still green.

The determinates started April 6 and put in pots (1-4 gal) have set fruit and again the Sandpoints are starting to turn a light yellow-green but not blushing yet.

Has it been warmer than usual there?

Oh, I'm sorry! I forgot to say that they are in hoop houses! So, yes, it is warmer, and yes, we've had some very warm days already. I have 28 varieties (4 are planted outside the hoop houses). The ones that have ripened: Debareo (came from 5-gallon pot), Chadwick Chery (from 5-gallon pot); Black Cherry, Super Sweet 100, Snow White Cherry, Japanese Black Trifele, Brazilian Beauty, Black Prince, Yellow Russian, Ethel Watkins, Black Brandywine (not True). I think that's all. There is black plastic weed fabric over the ground in the hoop houses, covered by straw, so there is probably lots of additional heat (first time I've done this, which the grasshoppers love, unfortunately). Yes, I think greenhouses are the only way to go for tomatoes and peppers if you live in a colder climate.

Also, Cherokee Purple and Black from Tula have ripened and I have a huge Brandywine OTV about ready to pick. The Black from Tula was a 12" plant in a 4" pot, and it was one of the first to ripen, so I was wrong about the 4" pots, though for the most part, the ones that were that size are not ripening like the ones that were in bigger pots. I love the blacks! I also believe they do better in colder climates. I wonder if there is anything written to back up that theory. I chose a lot of Russian varieties when I moved to MT, instead of growing all of my favorites that did well in CA. One thing I do that might increase the vigor of my plants is that I try to not let them experience temps below 50 degrees F. If I can't do that, then at least 45 degrees. And planting out a little later does not slow them down; in fact, later planted ones often do better than those I try to get an early start with (unless I can keep those early-planted ones really warm).

The average time listed on the tags of my plants is about 75-90 days til they start to produce, but I'm pretty sure thats the same time that it is supposed to take these plants to produce from ungerminated seeds. The DTM is pretty much a parameter defined by time from transplant to first ripes. One important modifier of this is weather conditions. For MY typical weather, I add about 2 weeks to the advertised DTM to establish a more realistic time period. With optimal weather and nutrition the putative DTM time frame can be much more nearly approached and sometimes the actual DTM can be fewer than the putative DTM.
Reggie