Why is clay bad for plants?
One last thing that can be a drawback to clay soil is if you have a boggy area, clay soils can limit the amount of air plant roots get when they are saturated. If you have a boggy area select plants that tolerate wet soils. Leave plants that need good drainage, to other parts of your garden. Clay does have the disadvantage of drying quickly. This can be a problem for moisture loving plants such as ferns or when attempting to germinate seeds. Clay also has the tendency to form a white crusty layer on the outside of the pot.
Which is better for plants, clay pots or plastic pots?
Gardeners with a heavy hand at watering tend to over-water; their plants will probably benefit from clay. Other gardeners who wait for the wilting signal from their plants are better off with plastic. Plants which demand a well-drained, dry soil like cacti also prefer clay pots. Clay does have the disadvantage of drying quickly. This can be a problem for moisture loving plants such as ferns or when attempting to germinate seeds. Clay also has the tendency to form a white crusty layer on the outside of the pot.