Asparagus is one of the first green vegetables to pop up in spring, but this stalks veggie's season lasts for just two months, from April to June. A common perennial vegetable, asparagus is packed with nutrition, including vitamins A, C, and K, and it's an excellent source of dietary fiber.
Asparagus is easy to grow, particularly if patience is one of your virtues—you won't be able to harvest for a couple of years. But crisp, flavorsome asparagus spears are worth the wait. Go ahead and add asparagus to your veggie patch ASAP.
You can start asparagus from seeds sown when temperatures exceed 60 degrees. If your climate is cold, you can begin the process indoors around three months before spring planting. They'll germinate and sprout within six weeks.
Fill a pot with potting mixture, sprinkle seeds, and cover gently with the soil medium, then transplant the seedlings when the weather is amenable. You can't harvest seed-grown asparagus for at least the first year. The seed packet will give you specific details about your variety.
Asparagus requires well-draining soil that isn't very acidic—aim for a pH of about 7. Male plants are preferable, with greater longevity and more spears. Asparagus can last more than 15 years in the right conditions, so be discerning about where you plant. You need deep soil and a spot with no exposure to frost. Plant your asparagus away from annuals that can disturb its roots. Soak crowns (pre-prepped roots, an alternative to seeds) in water for at least half an hour before planting.
You need a sunny spot that receives at least seven hours of direct light. If asparagus is just one element in a veggie garden, plant it at the north end because it gets tall and can block light from reaching your other plants.
Asparagus derives energy from the sun to spur growth and the development of spears during the following season.
Asparagus needs water to achieve its tenderness. Give your asparagus one inch of water weekly during year one. Soak the soil if there's been no rain during the past week, and avoid the foliage to prevent disease.
Different soil types will have different watering needs—clay, for example, doesn't need to be watered as often.
Use a soil test to determine what fertilizer to use, and apply a portion in the fall before planting. Add more fertilizer or compost at the time of planting and then when harvesting is over. If you don't do a soil test, use a fertilizer with a 10-10-10 ratio of nitrogen, potassium, and phosphorus.
USDA zones three to eight work for growing asparagus—it's a winter-hardy vegetable that doesn't tolerate hot zones. You can grow asparagus in Florida, but it'll probably only last three to five years.
In more Northern regions, bury the crowns deeper to insulate them against the winter chill; nothing above ground will survive.
If you live in a cooler climate, fall will wreck your foliage, but leave it be for winter, and the dead material will capture snow, which protects the crowns from freezing. Cut the plants back to the soil surface, or about two inches above the ground, in late March.
On the other hand, if your winters are mild, you can prune in the late fall.
Harvest asparagus lightly in the second year, for up to three weeks. In year three, you can harvest for about two months. At its peak, asparagus grows an impressive two inches per day. Pick spears at least six inches tall, or let them grow until they're 10 inches high—you can just use your hand to collect the vegetable.
Freeze your harvested spears to preserve them, and if they become too skinny, less than the width of a pencil, stop harvesting.
You can divide the crowns in spring or fall. Dig under your asparagus plant to lift it out of the soil. Pull the roots apart to divide the clump into sections with two shoots each. These sections can be placed in prepared beds, and then you're good to go.
Asparagus rust, fusarium root and crown rot, and Stemphylium purple spot can compromise your asparagus plant. Asparagus rust leaves the stems with orange-y blemishes. Crown rot means poor growth. Certain varieties are more resistant to diseases; for example, Jersey Knight and Jersey Giant can manage crown rot.
Two types of asparagus beetles can damage your plants. The common asparagus beetle doesn't just eat the spears like the spotted beetle—it also eats the ferns. When they feed, they cause the asparagus shoots to bend over abnormally.
Look for the beetles in May, and if you see them, pick or spray them off. Aphids, caterpillars, and slugs can also pose issues.
Asparagus will liven up your garden by its mere presence. It is almost cactus-like in its appearance, and a straight ascent and height add visual interest. Just be sure to plant it at the north end of your vegetable patch. This sets it apart and ensures it doesn't affect other veggies.
Red charm peony buds look like asparagus when they emerge from the ground. Edible agave plants are members of the asparagus family that tolerate heat better.
There are multiple varieties of asparagus, and it comes in different sizes and colors. In the northern parts of the country, you may want to try high-yielding Millenium asparagus. Washington asparagus is very cold-hardy, and Purple Passion is, well, purple. Precoce D'Argenteuil is a type of white asparagus.