Potting on tomatoes

[benshort]

Hi,

I have some tomato seedlings that range between 5" and 8" tall which are in 3.5" pots. I have some 10L pots that I want to put them but I wondering if I should pot them into 6" pots for a few weeks first.

Any suggestions welcome.

Ben

[Odsox]

I delayed replying to this as I have no idea how big a 10 litre pot is, but assuming it's large I would recommend the 6" for a couple of weeks.
The roots stay warmer as they are closer to the edge and it saves on compost too.

[benshort]

The 10 Litre pots are 11" diameter and 9" deep so quite large.

[benshort]

So one for straight to the big pot and one for a gradual increase in pot size...

Maybe I'll try some of both as an experiment :D

[The Riff-Raff Element]

I'm a big-potter. Toms are deep rooted, so I'd be inclined to let them get on with it asap.

[greenishfingers]

As a relative beginner I tend to try both methods if I'm ever in any doubt,that way you maximise your success potential. Well that's my excuse anyway,to disguise the fact that I'm not really sure what i'm doing :)

[Thomzo]

For something like tomatoes, that grow pretty quickly, I'd go for big pot straight away. You'll be amazed how quickly they will fill it. Also, toms like lots of water and the bigger the pot, the more water it'll hold. Some plants, like figs and citrus trees, do better if their roots are restricted but these tend to be slower growing, longer-lived plants.

Zoe

[Odsox]

So it's as I thought, I don't have a clue about growing tomatoes.

[oldfella]

Drives one Potty, one for a wee potty, another for a big potty, to my way of thinking if some of the best Toms, I've ever seen, grow Wild in a Sewerage Station, I think they would survive in either, as long as it Is a Pottie

[Millymollymandy]

Depends. If they have already been hardened off and used to direct sunlight, then you can pot straight into the big pots. On the other hand if they need to be hardened off then repot into a bigger 'small' pot for the time being, then in a couple of weeks when ready to be out in full sun and the elements all day and night long, they will have easily filled the next size pot you put them in.

Also plant them deeper than they were in the small pots as this encourages more roots from the stem and sturdier plants apparently. I always do this with my own raised from seed as they tend to be spindly from growing indoors.

[benshort]

They are currently in a cold shaded greenhouse in my back garden. I've made room in the poly tunnel at my allotment so they will move in there.

So I think I will go straight to the large pots once I have moved them. I'm looking at some drip irrigation that I can connect up to the water butt in the poly tunnel. I think that my co allotment holder has some water crystal things that retain water and the roots can tap into, so I might consider using some of these too.

Thanks for all the replies. I'll post some pictures shortly.

[Odsox]

Depends. If they have already been hardened off and used to direct sunlight, then you can pot straight into the big pots. On the other hand if they need to be hardened off then repot into a bigger 'small' pot for the time being, then in a couple of weeks when ready to be out in full sun and the elements all day and night long, they will have easily filled the next size pot you put them in.

I agree (sort of).
It's probably not quite so important now as it is in early spring, but my experience is that it doesn't matter too much what the temperature at the top of the plant is, it's the temperature at the roots that controls the growth of tomatoes (and peppers).
You can grow and ripen tomatoes in the depths of winter with the foliage as low as 5c as long as the roots are at about 20c.

So getting back to the original post, as compost/soil is an efficient insulator if you take a plant that is in a 3.5" pot and put it an 11" pot you have a 4" barrier of cold wet compost between the roots and the sunny outside world, potting from 3.5" to 6" means that the heat only has to penetrate about an inch of compost before it starts to warm the root ball.

[Zech]

When my tomatoes outgrew their little modules, I potted them on into whatever I had available - mostly medium pots but some straight into big pots. I've noticed the ones in the biggest pots seem to be growing fastest. These were all in the greenhouse.

[benshort]

I agree (sort of).
It's probably not quite so important now as it is in early spring, but my experience is that it doesn't matter too much what the temperature at the top of the plant is, it's the temperature at the roots that controls the growth of tomatoes (and peppers).
You can grow and ripen tomatoes in the depths of winter with the foliage as low as 5c as long as the roots are at about 20c.

Oh that sounds interesting.. do you have any more information on this?

So getting back to the original post, as compost/soil is an efficient insulator if you take a plant that is in a 3.5" pot and put it an 11" pot you have a 4" barrier of cold wet compost between the roots and the sunny outside world, potting from 3.5" to 6" means that the heat only has to penetrate about an inch of compost before it starts to warm the root ball.

You'd think that the compost would warm up quite fast in a poly tunnel though right? Although equally I suppose it could drop quite fast too as the ambient temperature drops. Maybe I need to lag my pots



Most of my potted up tomatoes... I ran out of compost for the last two

[Millymollymandy]

Interesting Tony, maybe that's why the 3 I have in giant pots are doing much better than the ones planted in the soil, because the soil in the pots must be much warmer than the soil in the ground. But then the ground has warmed up early this year. I assumed it was because the ones in pots are warmer during the day, being against a wall facing southish which retains heat long into the evening or because they like my home made compost with with added fertiliser. Oh I dunno, perhaps this is all too scientific for me!