However, if the root is poking outside the plastic wrap, then that root is likely to die due to lack of moisture, not lack of nutrients. It also suggests that the plastic wrap is not properly sealed and the moist soil may have dried out. Thus, you may want to gently unwrap the plastic and inspect the soil for dampness. If it is dry, wet it. Then re-wrap the plastic, making sure that all of the soil and roots are sealed inside.