Asparagus requires about three years from seed to harvest, but should produce every spring thereafter. Start heirloom asparagus seeds early in a frost-free location with full sun and adequate water in rich, well-drained soil. Sow seeds no more than 1/2 inch deep and allow 1-2 inches from one plant to its neighbor. After last frost of spring, set plants into an outdoor bed in full sun, spacing the seedlings about 6 inches apart and carefully controlling weeds. Allow the growing asparagus seedlings to develop there all season, then transplant into final garden location the first autumn or the following spring. Final location should be in full sun and very rich soil. Young asparagus crowns (dormant roots) should be spaced 2-3 feet apart in each direction, and 2-3 inches deep. Add organic mulch as the young plants grow, never burying them; eventually the mulch should be maintained at 6-8 inches deep. Harvest spears starting the second or third season. Snap off spears just below ground level when they reach harvest size. Stop harvesting when the new spears begin to become spindly and allow plants to grow undisturbed for the rest of the season. When red berries develop, harvest and dry some for fresh asparagus seeds. After frost kills the feathery tops, cut them at ground level and dispose of them.