Awhile back someone gave me some very flimsy flower pots, they are made from black plastic similar to a bin bag, they are flat pack like a paper bag and are throw away after use. They come in various sizes from 2" up to quite large and are very useful but I have almost used them and I asked on another thread if anyone knew about them. No one had heard of them apparaently but I located some today. I had a carrier bag full with about 300 for a fiver but they are all 6" and the man said he knows he has some smaller ones in one of his sheds so he is going to have a look for me. He informed me that they are known as Polpots. I googled it and found out they are made or distributed by a firm in Malvern. They are ideal for potting on the small plants and when they are ready to go into the garden, you just cut this thin plastic pot off without disturbing the roots at all. I have most of the plants in my greenhouse in them.
Maggs, sorrry to keep you waiting, I am not an expert you understand but I know a few people who are. I am reliably told that spuds continue to grow beneath the soil surface whilst the foliage is growing above it. When the foliage stops growing, the potato's stop. Therefore, if you get an old dustbin for example, remove the bottom, or drill plenty of drainage holes in it and add about six inches of soil/compost. Space 4 chitted seed potato's at 12-3-6-and 9 like the numerals on a clock and lastly put one in the middle. Cover them with another 4-6 inches of soil and keep them watered but not too wet. When the foliage is about 5-6 inches above the soil level place another 5 spuds in between the them and cover with another 5-6 inches of soil/compost. With something like a dustbin you will easily get three layers and you could get 4. When the greenery shows signs of wilting you will need to tilt the bin and get a housbrick under the edge so you can scrape out the soil and spuds from the bottom. Then gently remove the brick until you want a few more. The spuds get smaller as you use them but they taste better than shop spuds. I use some specially made 3 tier containers from Webbs at Droitwich for mine.