No up potting
 

Anyone else here sow they're seeds in pot they will stay in till they are put in the ground? I have up potted for several years and decided to start them In 4x4x4.5 pots and leave them there till they are planted out. I absolutely hate up potting plants. I always feel like I'm going to break something. So far they look just fine,about 8 inches tall in 3.5 weeks. Kept on heat mat till germination of 4 days.

Nctomatoman did this one year and the ones he didn't up pot did worse than the ones he did.

Some plants do better by moving up in pots than not.
I think tomatoes may be one of them.

I have always thought a small seed in a larger container has issues with
water-logging. Not enough root growth to deal with moisture. Small seed cells
will dry out faster getting water when they need it by observation.
In a small cell it is more obvious when they get good root growth and get
thirsty. Good root growth can handle the moisture and feeds the green growth
above the soil.

Also a Realestate/space issue. If I have room for 12 tomato plants, I sow at least
8-10 seeds per variety. In a 36 cell 1010 tray. Three cells per variety. Then cull
at about 3-4 weeks. One per cell. The most strong and healthy. I then have three
plants of those 12 varieties. Insurance. If all goes as planned, I have my 12 and
I have extras to gift to friends and family.

(I grow hundreds but the basic formula works for me)

I did a germination test over the holidays, (I grow year round indoors)
testing seed starting soil, etc. They did so well I continued and now have some
early tomatoes that I'm just potting up in grow bags. Most are dwarf and micros.

1010 is 10x10inches. Easy to tend for the first 6-7 weeks. I do keep them longer
in small cells than most do. But I have limited time and it works for me. I do give
a good chat when I check every morning, :P, They seem patient until I can pot
up eventually.

[QUOTE=weaselbean;731028]. I always feel like I'm going to break something. [/QUOTE]

I think that's the idea. During the up-potting some of the small roots get broken during the process which sends a message to the plant that those roots need to be repaired and strengthened. I go from a small 6 pak sized pot that has a couple or three seedlings in each section to a 2"X2"X3" pot for each individual plant. The larger pot is where the plants stay until planting out in the garden. Others have different methods, but most folks agree that up-potting is necessary.

And yes, during the up-potting I occasionally snap a seedling in two but that is why I plant about double what I need for myself. The seeds are cheap and I call it insurance. Then I give the extras away. Tomato seedlings are tough and don't be afraid of rough handling...they can take it and do better for it.

Although I nowadays use little cells, in the past I've used full-sized pots. The advantage is all that extra soil holds water. The tablespoon of soil in the cell dries out too quickly. I'm always afraid I'll kill the little seedlings by drying them out.

What I do for good root growth is to do at least two potting ups to allow for deeper "repotting" of the seedling, resulting in some covering up of the lower portion of the stem. This takes advantage of tomato seedlings adding roots to the stem parts that are covered with mix. In the end, it forces the plant to work heavily on the root system before you take it to the main garden where a larger and more robust root system is very important.

Typically, my process is to move small seedlings into individual cells in a 72 cell tray. Then they go to a 9 oz plastic cup and from there to the garden.

I'm skipping one step by not transplanting them from the seed tray as seedling into solo cups but directly in the 10cm containers (I guess those are the same as your 4inch containers) once they are ca 20cm (7inch) large. I bought special seed trays for this with extra deep cells I filled for 2/3 with lighly fertilized potting soil and the top 1/3 with a seeding medium. This works like a charm. Very good root development, better than in the solo cups.

Other than having to touch dirt less & making a 1-time mess, I don't see any benefit to the "sow & leave" method.

In addition to the space considerations & moisture issues... If you are putting >1 seed per pot, there will be plants wasted.

More importantly, up-potting tomatoes, & setting them deeply when doing so, builds better root systems.

I am going to experiment this year with some single pot planting (1 seed per 4" pot) and the regular pot up method. After looking at Joseph's philosophy of getting varieties to behave with only planting, growing and harvesting (forgive me if I've over-simplified) it seems that plants know what to do by themselves, otherwise we'd be pretty hungry by this stage of existence. When you are growing hundreds or thousands of seedlings, transplanting up is indeed a big job.

I start them in cell packs but I pot them up into 6" pots when they get tall enough to touch my lights at their highest setting. I have a small light set up.

I start in soiless seed starting mix but I pot up in potting soil and I bury the stems deeper.

At this point they are able to live outside on the front porch and start hardening off.

I start mine in plastic cups or in 4inch nursery cups. I fill it with 70% potting mix and start the seeds. When the seedlings get taller, I fill potting mix to the top. From there it can grow to 8inches tall and I can transplant it directly to containers. But for transplanting into the ground I prefer to up pot it until it's at least 1ft tall.

One year, I up potted some plants of a single variety and to see what would happen, I removed a few from the germination cells, disturbed the roots a little and returned them to their original cells. Both the up potted and the disturbed plants out performed the undisturbed plants in growth rate and over all health. I wasn't expecting the eight or ten disturbed plants to perform so well. I don't recommend the procedure, but it was interesting. I am kind of lazy and don't always up pot. The plants I grow in the germination cell's until plant out are usually smaller when planted out, but they seem to catch up with the larger plants pretty quickly. They seem to be waiting for someone to open the starting gate so the race can start.

I started germinating my tomato seed in early January in six cell, germination cells. I up potted some intending to plant them out in late March. I kept a few plants in the germination cells as extras in case of a hail storm or some other calamity. Some of those still in the cells are now over twenty four inches tall and healthy, but very leggy. They will either be used in an emergency or go into my compost bin.

I use 1020 flats for germination and start in either 72 or 18 cell inserts. I plant heavily for older seed and 1 seed per cell for newer rare seed. Everything tomato gets started in April after peppers are planted. I have 3 flats germinated, 2 more planted and 8 or 9 more to plant. Up potting I reserve for very rapid growers. Most I let get root bound in their cells and plant them past the lowest set of leaves when they go into the ground. I also pot them up if I'm giving plants away. But I have enough tomatoes started that I'm not worried if they're a little stressed. They are misted often, get good air circulation and are under adequate lighting. Up potting might get tomatoes on some varieties a week or two earlier. But once they get planted out most do fine if they avoid something eating them. So up potting isn't a priority for me.

I use 72 cells/ 1020 to start, and the main reason for potting up is the same as Oakley. In my environment, the extra moisture from watering a solo-sized pot would be too much for a tiny seedling because the environment is cool. Especially true for peppers which hate cold wet soil the worst. And space is also an issue.

But I can see how, in a warmer climate, it may just not be worth the extra trouble because plants are growing faster and the potting mix is drying out fast enough they aren't bothered.
What I have noticed about small seedlings in big pots, is that they are slower to put on top growth and seem to instead put more energy into small roots trying to fill all the space. But seedlings in little cell packs have only enough space to focus their root growth into a main one with branches, so you have a sturdy main root to start with, and strengthens further as you pot up.