Leave the dead fern growth intact over the winter. This catches snow for additional soil moisture and keeps the soil temperature about 5 degrees F cooler than bare soil with no covering of dead fern. The cooler soil temperature is helpful in delaying the early emergence of asparagus in the spring, when air temperatures might rise prematurely and then fall again, predisposing the spears to frost damage. Frost-damaged spears should be snapped and discarded. Remove the old fern growth by cutting or mowing as low as possible during the first week of April in central Ohio.
Dead stalks are very sharp and can easily skin knuckles when harvesting new spears.
Weed Control Weed control can be accomplished by hand hoeing and cultivating during the planting year since there are no herbicides labeled for use in asparagus during the first year. Do not use salt as a weed killer. It will not harm the asparagus, but it inhibits water penetration in the soil. Also, rains can leach the salt out of the asparagus bed and into the rest of the garden, injuring other vegetables that are less salt tolerant than asparagus. Harvesting Harvest asparagus by snapping 7 to 9 inch spears with tight tips.