Over potting is it a myth

Never tried it Tarragon, but maybe it depends on the type of plant? What have you started off in large pots?

Gardening is trial and error and you should do what works best for you.
Potting up into large pots now probably won't hurt as everything is warm, space isn't an issue as you don't have to worry about frost but in the colder months when toms are sat in large pots of soggy soil they really don't thrive for me.

Experimenting is part of the fun of gardening.

Tarragon if you don't like potting on then don't do it, like Scarlet says do what works best for yourself.

You could take 2 identical seedlings pot one up gradually and the other straight into the final pot and see hw they do. At this time of the year they probable both do fine, but in early spring when it's still cold and the compost is soggy the result may be different. You'll have to try it then to see what happens.

If it works for you, then do it!
There is no "One Pot fills all" answer.

Old saying 'ask two gardeners the same question and you will get three different answers'.

One point is if you have kept the plant cramped in a small pot it will certainly thrive when potted on no matter what size pot you put it into.

I tend to agree with Steve Solomon's writing on this topic. Only start tomatoes, peppers, and eggplants as seedlings unless you must have other things early. Otherwise plant seeds directly into the garden soil when the time is right.

Plants have a way of catching up when planted that way.

I'm in Iowa and I can't get over people starting sweet corn in pots. There's an old saying about corn planted directly in the field/garden; "Knee high by the 4th of July." I can tell you that the farmer who planted his corn this spring across the road from me didn't start his corn in pots. He has hundreds of acres of corn planted.

It's not so much the frost season in the UK, DWS, as the fact that nights can be very cold in the UK till quite late on and the ground is often extremely wet. So seeds are liable to rot. People do what works to ensure they get a crop. And it's not as if looking after a dozen or two sweetcorn seeds in pots is going to break your back.

With regard to tomatoes, I started off my tomato seeds in modules. Then my circumstances got complicated and I couldn't plant them out when ordinarily I would have done. So for the first time ever I potted them on as an interim measure. They eventually got planted out when the nights were around 11 ºC minimum, though they did have to cope with a night or two of around 5 ºC. By the time they went in the ground, I have to admit they were a bit pot-bound. They are the best tomato plants I've ever grown. I don't know for sure that it's because of the potting on, but I'll certainly be doing it again.

This season I began my tomatoes and peppers from seeds for the first time. I was a little late but by the time the tomatoes were 4" high or so the weather was warm enough so I planted them in the garden. After about 8 to maybe 10 days they had doubled in size and become even stockier. I doubt I'll buy tomato plants or pepper plants again. I do need to work on my grow light arrangement a bit.

I also began cucumbers in pots. Some squash seeds were planted into the garden about the same time I set out the cucumbers. The cucumber plants have done quite well as have the squash seeds. In another couple of weeks I doubt I'll be able to tell the difference in the size of the cucumber plants and the squash plants. I'm sure the cucumber plants will be longer than if they had been planted directly in the garden later but it may not be noticeable by then. I'm not going to bother planting cucumbers in pots again.

I went to Hortus Loci for a pre-Hampton Court Flower Show briefing (will be on the Perennial concept garden, come and say hi!) which included a nursery tour. Interestingly for this, they put ALL their 9cm plugs straight into 3L pots and increase size from there, rather than messing about at the smaller end. Might just give it a go myself next season, their plants looked amazing.

I have two problems that mean I have to use pots. (1) Concrete, I do not have a garden as such so everything is grown in a container of some sort. (2) Space, hence potting on in stages means more plants per square foot. As we all keep saying what ever suits your circumstances and gets results.

Do you have slugs in Iowa. DWS? That's primarily why I start most things off in modules or small pots

I tend to look upon it that a seed/plant has generally fallen off the plant and grown where it has landed. That is usually without our intervention on some bit of soil.

That bit of soil is not usually restricted, so naturally they would grow (in our case) in some ground that is sort of bounded by the size of the British mainland. My guess is that the British mainland is slightly bigger then a pot.

If a plant/seed could only get started in a pot then it would not exist, mankind has not been around for long, and the seeds were quite happy growing before we appeared, and when we did appear we did not make a plant pot as the first object.

We bung them in a pot for our convenience and often to get them started off artifically earlier then they would otherwise. That is my only reason for using pots, part of the present convenience is to prevent the assortment of slugs and snails from having a nightly banquet.

There can the the instance where the seed will not germinate outside (tenperature or length of sunlight) and so we aagain artifically create an environment for the seed to germinate in. In this case a pot is again convenient - or build your own Eden project.

I will use whatever pot of sufficent size comes to hand, but they are usually on the biggish size. As mentioned elsewhere the 25cm ones I find fairly good. But whatever I use they are always big enough that there is no restriction on the plants growth. Also moving a plants from pot to pot can result in an accident and a broken plant.