How high should the asparagus be when I begin filling the trench? How much dirt should I add each time I fill it? I planted asparagus " crowns How high should the asparagus be when I start filling the trench? How much dirt should I add each time? I planted asparagus " crowns " this spring this spring by following the instructions in the Washington Star News Garden book. The instructions said to dig a trench 6 to 8 inches deep, cover the bottom with compost or manure, put in the plants about 18 inches apart, cover them with about 2 inches of top soil, and gradually fill the trench as the shoots grow. I now have a shoot about 2 inches tall. The book does not say when to begin filling the trench or how much dirt to add each time. A second book I consulted does not even mention a trench.
Charles County Maryland
The young shoots grow quickly, as they mature the stem will appear woody and reach about 18" tall. At this stage ,you can start adding about 2" of fill back into the trench. Continue the process as new shoots continue to appear.throughout the summer.