Asparagus is a perennial vegetable plant that's usually grown from crowns, which are 1-year-old plants. Asparagus plants take about three years before they mature and are ready for harvest, but then the plants will produce spears each spring for 15 to 20 years. You should plant your asparagus crowns in early spring, as soon as the soil is workable, and in a site that has well-draining, slightly acidic soil with partial sunlight.
Water your asparagus deeply once or twice per week when rainfall is less than 1½ to 2 inches. Soak the soil around the plants generously, ensuring that the soil is absorbing the water and it's draining well.
Weed around the asparagus plants at least once each week, either by hand or hoeing very shallowly. Be careful not to disturb the asparagus plants' shallow, tender roots.
Spread a 4- to 8-inch-thick layer of straw or hay mulch around the base of the asparagus plants when the plants are at least 4 inches tall. Add more mulch to keep the layer to the desired thickness each year in spring or fall.
Cut back the dead foliage from the asparagus plants in late fall. Side-dress the rows of asparagus in the spring and fall by spreading a 1-inch layer of organic compost about 4 inches away from the plants.
Harvest your asparagus lightly in spring of the second year, if you planted them from crowns. Harvest the asparagus regularly in the third year, cutting off the spears at the ground level when they're about 6 to 8 inches tall and thicker than a pencil.