Buy Asparagus seeds online. Asparagus is a perennial vegetable, which means it will come back from year to year without replanting. When the bed is properly prepared asparagus can last for 20-30 years. Make sure the bed is well prepared before first planting asparagus seeds in your garden and make sure it has a place that won’t be disturbed from year to year. Heirloom seed options. All seed is non-GMO.