When to Harvest Russet Potatoes?
Harvest Time
Russet potatoes are normally ready to harvest between 80 and 115 days after the seeds are planted. A good indicator that the potatoes are mature enough for harvesting is when the above-ground vines die. This sign generally appears in late August or early September.
Potato Extraction
Since the potatoes are not visible, care must be taken not to cut into their flesh when harvesting. They normally develop between 4 and 6 inches below the ground, so the shovel or spade used to extract them should cut 1 to 2 inches deeper than that around the plant perimeter to avoid cutting into the fresh tubers.
Reaping Options
If "new" potatoes are desired, the small immature potatoes require harvesting in July, before the vines die. Cooks frequently favor little potatoes for roasting or stew ingredients.