Pots come in a variety of sizes and materials. This page compares some of the different types of pots available on the market and what they are most suitable to be used for.
Black plastic pots are cheaper and absorb more heat (warmer soil aids plant growth) than any other type of pot. LEFT TO RIGHT: 13 cm, 20 cm, 25 cm, and 28 cm pots. FOREGROUND: Accompanying black saucers. These size pots are suitable for growing herbs and smaller vegetables such as rocket and lettuces.
Are lighter than earthenware pots, making them more portable, but they break down more quickly than black plastic pots. However, their lighter weight makes them ideal where weight is an issue, such as on wooden decking.
Self watering pots have a reservoir of water at the base of the pot that the plant/s in the pot can draw upon.
LEFT: A self watering pot with young picking lettuces in it. RIGHT: Interior of a self watering pot showing the divider that keeps the soil in the pot separate from the water reservoir. Note that the photo on the left was taken some years ago. These days I sit self watering pots in a saucer to catch any overflow from the pot’s reservoir.
As far as I am aware they are only made of coloured plastic. Though there are self-watering inserts for conventional pots, in including terracotta ones, however I have never tried them.
LEFT: Earthenware pot. RIGHT FOREGROUND: Earthenware pot. RIGHT BACKGROUND: Terracotta pot (type of earthenware pot using a specific clay mixture) with Aloe vera growing in it. All these pots have been glazed to seal the outsides. Unglazed pots are quite porous, such pots need more water than comparative sized glazed pots as they lose moisture through their sides via evaporation.
Technically styrofoam boxes are not pots, but they are useful substitutes for pots, especially if you are on a very tight budget as they can usually be sourced for nothing. I mainly use them to grow seedlings, but they can be used to grow most types of vegetables, though I do not recommend that they be used to grow fruit trees.
Since I bought the bulk of my pots many more types of pots have come on the market, including cascading pots, wall pots and pots made of composite materials that look like earthenware but weigh less. However, as I have not used such pots and this website is based on my personal experiences, I have not included them in this article.