20 Why is repotting necessary? 
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this. If the soil is well drained, it dries out too rapidly in a clay pot 
which in itself absorbs moisture from the soil. A clay pot becomes 
chilled as the water evaporates through its pores and the roots seek- 
ing the walls of the pot also become chilled. Or during hot dry 
days the moisture is all drawn from the soil and the root tips are 
burned or dried by the pot’s nonresistance to the heat. It has been 
demonstrated that plants make better growth when a 5-inch clay pot 
is set inside a 6-inch pot with an insulation of sand or moss between 
the two pots. This disproves the advantages of clay pots in favor of 
glazed pots which tend to keep plants at a more even temperature. 
Glazed pots must have very porous soil so that water will never 
stand on top of the soil. There must be a sizable drain hole in the 
bottom over which moss, broken pots, charcoal and sand are placed 
to drain the water from the richer soil above. Glazed pots have the 
advantage of being decorative and also demand less attention because 
they do not require water as frequently during the hot months. 
Succulents will flower better if the pots are not too large in rela- 
tion to the size of the plant; it seems that reasonable restriction of 
root growth encourages flowers. However, the size of the pot should 
be a little larger than the plant’s circumference including the spines. 
If old pots are used they should be cleaned with a stiff brush and 
sterilized by boiling in hot water. This kills all fungus growth such as 
the green algae which is seen so frequently on pots and covering the 
soil. New clay pots should be soaked in water for a day or two to 
clean the pores and to wash out some of the alkali. 
The purpose of repotting is to replace worn out soil or to provide 
more space for roots. In some cases application of food (leaf mold, 
manure, or prepared plant food) may temporarily take the place of 
repotting. Small plants grow better when planted together in a large 
pot or preferably a wooden tray which prevents too rapid drying out. 
Miniature pots can neither retain moisture nor sufficient food supply 
for the smallest plant. 
Potting may take place when new growth announces the growing 
season. How does one tell when new growth is evident? There 
might be a brighter coloring of the spines at the top of the plant, 
