For Asparagus plants be sure to dig about a 6" deep trench in soil that does not flood and is in full sun. Place the roots spread out in the trench and cover with 2-3" of soil and water thoroughly. As the plants begin to emerge, back fill the trench until it is full as the plants grow. No harvesting of any green shoots should be done this year. Asparagus is a perennial vegetable that can be very productive for 15 years and more.