Chemical Weathering. Chemical weathering takes place in almost all types of rocks. Smaller rocks are more susceptible, however, because they have a greater amount of surface area. Chemical reactions break down the bonds holding the rocks together, causing them to fall apart, forming smaller and smaller pieces.
Autos generally are ready to harvest sooner than photoperiod. Most autos are ready to harvest 65-90 days after being sprouted from seed. Some super autos have been bred to grow very big and can take up to 100 days before harvest.
How Long Do Onions Take To Grow? From planting to harvest depends on the type and whether they were started from sets (50 to 60 days), seeds (110-125 days), or transplants (70 to 90 days). Harvest when one-forth to one-half of the tops of the onions have fallen down.