Asparagus is a popular vegetable that can be grown successfully in Ohio home gardens. A desirable aspect of asparagus culture is that annual planting is not required because once the crop is fully established (three years), it can be productive for 12 to 15 years or more if given good care. Because asparagus is a perennial crop, it should be planted at the side of the garden so garden plowing and cultivation of annual crops can be accomplished conveniently. Gardeners using large garden tractors to prepare the garden soil and cultivate crops may find an asparagus bed in the middle of the garden to be more convenient.
Lime and fertilizer applications to the soil are best made using the results of a soil test as a guide. We (Ohio State University Extension) can assist you in making arrangements for a soil test and in obtaining recommendations for lime or fertilizer applications.
Asparagus plantings can be established by using either seed or crowns. Crowns are fleshy stems with an established root system. To save time in establishing the planting, it is suggested that one-year-old crowns be planted rather than seed. Crowns are available from garden centers and some seed houses. The new male cultivars such as Jersey Giant, Jersey Knight, or Jersey King, are recommended for planting in Ohio gardens.
Set the crowns as soon as the soil can be worked. Under Ohio conditions, spring plantings have usually given better results than plantings made in the fall.
Plant the crowns in rows to make weed control easier to accomplish. After marking off the row, furrow or spade out a trench at least 10 inches wide and 8 inches deep. Place some loose soil in the bottom of the furrow so as to establish a planting depth of 6 inches. Place the crowns 18 inches apart in the bottom of the furrow with the buds pointing up. Spread the roots well across the furrow. Cover the crowns with 2 inches of soil initially. Gradually fill in the furrow as the spears grow. By using this procedure, small weeds growing in the furrow can be covered and killed. The final depth of soil cover over crowns should not exceed 6 inches in clay soils or 8 inches in lighter, sandier soils.
Each crown planted will produce about ½ pound of spears annually when fully established. In small gardens 25 to 50 feet of row will supply the average family with enough asparagus for table use. For freezing and canning, as well as fresh use, increase the row length or plant additional rows.
Generally, no asparagus should be harvested during the first two seasons. By making no harvests until the crowns are well developed, they will be more productive over a longer period. A few spears may be harvested the third season. During the fourth and subsequent seasons cutting may be continued for six weeks. Discontinue harvesting when the spear diameter decreases to a diameter equal to that of a lead pencil. After harvesting, allow the fern growth to develop and build up the crown for a good crop the next season. Allow the tops to remain over winter. Remove them by cutting at ground level the next spring before growth resumes.
Source: OSU Ext., Steven C. Prochaska