Those root crops are all cool-weather tolerant, so you could certainly get away with starting them at the end of April and into early May. However, the most important factor is your garden’s soil temperature. If the soil temperature is below 10°C (50°F), most seeds won’t germinate or will take a longer time to get started.
In any case, you’ll want to keep a close eye on the forecast and cover any young plants (especially potatoes) to protect their foliage from frosts.
Those root crops are all cool-weather tolerant, so you could certainly get away with starting them at the end of April and into early May. However, the most important factor is your garden’s soil temperature. If the soil temperature is below 10°C (50°F), most seeds won’t germinate or will take a longer time to get started.
In any case, you’ll want to keep a close eye on the forecast and cover any young plants (especially potatoes) to protect their foliage from frosts.