When to pot on

If you grow things from seeds it is important to know when to 'pot on'.  
  

40 sunflower seedlings ready for their pots

The first move is called 'pricking out' and that is done when the plant forms its first two (or more) true leaves.  Easy to see here with the sunflowers.  The paler two leaves on the sunflower are the cotyledons.  All seeds will produce these first two leaves and they are pretty much the same shape on every plant and don't look like the proper leaf.  Don't move them on at this two 'leaf' only stage wait until the real leaves start to form.

You then dig them out gently, holding them by the leaves not the stem and put them into small individual pots.  I'll show you this when I do them.

Right now I just wanted to show you how seedlings look when they are ready to move on.

some ready, some are not

These three different veggie seeds were planted at the same time but germinated at different rates - exactly how it should be.  Every plant will have its own gestation time.

On the left are peppers and they just have their cotyledons (not proper leaves) and are not ready to move on.  The centre row are tomatoes and most of those have their proper leaves but only just.  This is also the time to decide which are the best of the bunch as I won't want all the ones that have germinated.  The right hand row of cucumbers have most definitely formed their proper leaves and again one of these is enough, two for belt and braces I suppose.

cucumber

tomato

The tomatoes show up the big difference between cotyledons and proper leaves - they look totally different.

peppers

No sign of a proper leaf yet.