Asparagus has male and female plants. Female plants produce spears that eventually grow to produce flowers and seeds that not only take extra energy to produce, reducing spear production, but also create a jungle of little asparagus plants. Unfortunately, these young seedlings aren’t productive and are mostly just weeds. Male plants don’t have flowers and seeds, and are therefore more productive than the female plants.

Unlike most of the vegetables mentioned in this book, asparagus is a perennial plant (Click here for the lowdown on perennials). The crown (the short stem near the roots) actually expands with age, producing more spears each year. After the spring harvest, let the spears grow into towering ferns that feed the roots for next year’s crop. Because asparagus is a perennial, you start harvesting in spring when the spears emerge and stop harvesting six to eight weeks later:

• Year one: Let all the spears grow into ferns.

• Year two: Harvest only those spears whose diameters are larger than a pencil; your harvest window is about three to four weeks in the spring. Snap off spears by hand at the soil line when they’re 6 to 8 inches (15 to 20 cm) tall.

• Year three: Begin harvesting only the pencil-diameter-sized spears for six to eight weeks each spring. Stop after that and let the spears grow into ferns to replenish the crown and roots.

You can cut down the ferns after a hard frost in fall or winter. Weeds are the number one downfall of most asparagus beds, so keep the beds well weeded.