Things You'll Need
String trimmer or lawn mower
Compost or well-rotted manure
Straw or chopped leaves
Asparagus is inextricably tied with spring, as it is the first vegetable to emerge in the garden (usually around the time daffodils are blooming), and its harvest season is over by late spring or early summer. While asparagus plants may only produce for a few weeks a year, they need care all summer and fall if you want to harvest tender stalks the following spring. One of the most important parts of maintaining a productive asparagus bed is winterizing the asparagus plants. Removing spent foliage to eliminate overwintering pests and covering the asparagus crowns to prevent cold damage is necessary to maintain a healthy asparagus bed. A properly maintained bed can easily produce for 15 to 30 years.
Allow asparagus foliage to die before winterizing your asparagus plants. Asparagus foliage will turn brown or yellow and begin to fall back to the ground when it is dead. This usually happens after the first or second hard frost. In frost free areas the foliage will die in late winter.
Use a string trimmer or lawn mower to cut the asparagus foliage back to 2 to 3 inches tall.
Spread 2 to 3 inches of compost or well-rotted manure around the asparagus plants.
Cover the crowns (the place where growth emerges) of the asparagus plants with 4 to 6 inches of straw or chopped leaves.
Remove the straw or chopped leaf mulch in early spring before the spears emerge.
Only remove the straw or chopped leaf mulch from half of the asparagus bed. The part of the bed that had the mulch removed will produce spears first. The mulched part of the bed will start producing spears two to four weeks later thereby extending your asparagus season.
Do not compost asparagus clippings. Asparagus beetles and disease pathogens hide in the foliage composting may not kill all of the pests. Burn or throw away the clippings as soon as you can.