Growing asparagus isn’t especially difficult, but it has that reputation. Yes, it’s a little tricky to plant at first. Yes it requires fertile, well-drained soil. Yes it takes a few years to get a decent harvest. However once established, I’ve found asparagus to be relatively low-maintenance, and a true garden favorite. There are a couple key practices to remember though when you put your bed to bed for the winter.
Like its cousins the onions, Asparagus officinalis is a member of the Liliaceae or lily family. It’s been cultivated since ancient times. Asparagus is a dioecious, which means there are distinct male and female plants. In recent decades, the all-male hybrid varieties from New Jersey (like the “Jersey Giant”) have become very popular. Male plants produce a greater number of spears, and no berries which eventually germinate and become like hard-to-pull weeds. Asparagus does not compete well with weeds. Weeding the bed is generally by hand because any deep cultivation can damage the asparagus. Neglected, weedy beds do very poorly. Asparagus plants have three parts, the top (fern), the crown (just under the surface where the buds form), and the roots (below the crown). The fern creates energy which is stored in the crown. The more energy and nutrition stored in the crown during the summer and fall, the more spears in the spring.
That’s why it is important not to cut back the ferns until November when they’ve completely browned and lost all viability. In fact, it is always the last act of my gardening season. I like to cut the the ferns a few inches above the surface, pull any weeds, and then cover the bed with a good 6 inches of lightweight mulch. I use composted wood shavings from the chicken coop. It is excellent fertilizer and not too heavy. The cut fern stubs help hold the mulch over the crowns, providing a good insulating layer against the winter cold. Healthy and robust crowns are really the key to growing asparagus. By next growing season, nutrients from the manure will have leached-in, and the thick layer of shavings will be mostly composted and reduced. Each year the bed does get a little more raised, but that’s a good thing. It makes for better drainage which is important for the asparagus roots.
A well-maintained asparagus bed will be productive for 20 years or more. There aren’t too many cultivated plants which can claim that. With just a little proper care in the fall, you will be rewarded by many juicy green spears when spring comes around. Asparagus can be that easy.