[pulse]

This may sound like a silly question  :blink: but I am still quite new to this vegetable growing adventure.

Seeds are planted in seed trays, then when big enough moved into small individual pots. Then as they grow bigger they are often repotted into larger and larger pots.

My question is this: Why not move the seedling into the largest pot first to save having to repot several times? What is the reasoning behind all the repotting?

Thanks

[peapod]

I was thinking this last year, as I potted my chillies straight into the large pot and didnt get as big a crop as I expected.  I THINK (and only think!) that they make too much root material too soon instead on concentrating on the top growth
Im sure someone can tell me why we should do it properly 

[andreadon]

Dr Hessayon says:

"a suitable sequence of pot sizes is 3in-5in-7in-10in.  Never miss out a stage in this sequence, but stop when a suitable size is reached."
and:
"If the plant is pot-bound it is normally necessary to pot on."

So we know that we must never pot-on into too large a pot, but we don't know why!

"ours is not to reason why, ours is but to do and die"
 
but I am inclined to agree with peapod for the reason - it would encourage too much underground growth.

[mumofstig]

Doesnt make any sense though cos if you sowed them direct in soil they would have a 'very big pot' to grow in

[Elcie]

I don't know the answer but I usually think of it in the same ways as babies.  They start their life in a small crib or moses basket - we don't chuck them straight in a double bed!

[FRUITFULL]

Great way of putting it Elcie 

[Stripey_cat]

Compost in a pot can get pretty manky round the edges if the plant in the middle is too small!  Also, traditionally, you start them off in a very sandy, low fertiliser soil and pot them on into gradually richer mixes.  Most of the time, I skip the first step (sow straight into modules in John Innes no1, rather than seed trays full of seedling mix).  Also, plenty of things can go straight into the soil from a 3" or 5" pot.  Finally, it's easier to keep a lot of small pots or trays in a propagator (or your best sunny windowsill) than a load of 5" or bigger!  Of course, you still need somewhere suitable to grow plants on after the first potting on.

[Kagganz]

Oops I've made a boo boo!!!

I've gone from a 5inch pot (not me personally you understand) to a great big final pot with my dwarf french beans and my courgettes, (I know it's too early but I'm impatient and they are in my cold greenhouse).  Should i put the courgettes back into a smaller pot, I've literally just done it 15 mins ago.

Drums fingers impatiently 

xx

[Kagganz]

Plus like Mumofstig said, if we pot straight into the ground then thats  a mahoosive type pot isn't it?

[lucywil]

i think it is to do with watering, if a small plant is in a large pot the compost will hold more water than it needs which could cause to plant to rot.

although i have to admit i didn't think about this when i put a small pepper into a large pot, so i am being careful with the watering, and it is in the conservatory so it dries out quite quickly

[little sweetpeas]

Space!

I wouldn't be growing half as much if everything went into the larger pots right from the off. Where would I put 42 tomato plants, 16 cucumbers,12 melons etc

I think the point about the different pot sizes is to make sure when the plants need to they move onto the next size or they won't have the space to develop. The compost is toped up with fresh stuff. However I doubt it matters if you miss out some pots I normally on repot my tomatoes and peppers twice before final planting

[Aunt Sally]

It's very logical really.

When you plant or sow into the ground the plants roots radiate out into the soil as nature intended.

When you sow into a pot exactly the same thing happens the roots grow straight out from the plant but bang into the side of the pot. They then follow the edge of the pot round in circles.  When repotted they do it again. This means that each small sucessional layer of soil created by the repotting is filled with roots and any water and nutrients there are taken up by the plant.

If you pot into too large a pot the roots whizz out to the edge, circle round it and don't utilise the soil nearer the plant well enough.  This under utilised soil due to our watering then becomes waterlogged and sour while the soil near the edge where all the roots are becomes dry as that is where the plant is taking the water from.

Result one unhappy poorly growing plant  

[richyrich7]

Personally as I understand it.  That if the pots too large the compost can go sour before the roots get to grips with it, a lot of the available nutrients in compost are water soluble and could be washed away before the plant makes use of it. So it makes sense to pot on.
Also it's wise to remember with some plants heavier fruiting is encouraged by them getting a little root bound ( stress triggers survival = make babies !!) so a big pot all you get is lots of leaf and few fruit.

[Kagganz]

Oh dear, the mod's have it!

I'm 'orf back to the greenhouse then,

'here courgy courgy, back to the small house for you' 

Ta  xxxx

[Kagganz]

They're not happy bunnys.

I've took them out but have used their 5 inch pots for toms!

So they are back in their baby pots.

Orf to Wilkos then.............

But while I'm here can anyone tell me what I've put in this one?

 'Cos I can't for the life of me remember!