If you are growing potatoes through straw mulch, once your potato plants poke up from the first layer of straw (which is about 3 to 4 inches) and reach a height of about 4 to 6 inches, then you can cover the whole plant with another layer of straw mulch (some gardeners leave about 1 inch of the plant exposed when covering them, so that the leaves can still be exposed to light and make food for the plant). Continue doing this (covering the plant with straw once exposed plant height is 4 to 6 inches) until you have a layer of straw that is about 12 or so inches high. Then monitor the plant as it grows; do not cover the entire plant again, but do replenish the straw if it gets dislodged or flattened — you don’t want sunlight to get to the tubers, or they’ll turn green and become bitter and not safe to eat.
If you are growing potatoes through straw mulch, once your potato plants poke up from the first layer of straw (which is about 3 to 4 inches) and reach a height of about 4 to 6 inches, then you can cover the whole plant with another layer of straw mulch (some gardeners leave about 1 inch of the plant exposed when covering them, so that the leaves can still be exposed to light and make food for the plant). Continue doing this (covering the plant with straw once exposed plant height is 4 to 6 inches) until you have a layer of straw that is about 12 or so inches high. Then monitor the plant as it grows; do not cover the entire plant again, but do replenish the straw if it gets dislodged or flattened — you don’t want sunlight to get to the tubers, or they’ll turn green and become bitter and not safe to eat.