When agent Petty is out for a jog, it is clearly winter as the trees and shrubs are barren of all foliage. This scene is supposed to be during 4th of July in southern Missouri, everything would be fully green.
Jacob and Darlene are shown discussing their "crop" which is a field of poppies, suggesting that they make opium and then heroin. Their poppies have bloomed and therefore present no value as the source of opium. Opium milk is collected before poppies bloom, and it is very important that no rain falls on them before or during harvest, so "a hell of a storm" would be detrimental to their crop. However, it is discussed later in the series that the poppies in bloom are there for show and they previously told the sheriff about these. There must be other poppies being grown for the production of the opiates.