“How can I prevent asparagus beetles from attacking and how can I get rid of them?” Question from Carol of Drums, Pennsylvania
Answer: There are several cultural things that you can do to manage asparagus beetles. There are two types with similar habits and damage, the black and white adult common asparagus beetle (Crioceris asparagi) and orangish-red spotted asparagus beetle (Crioceris duodecimpunctata). First, it is important to understand their life cycles.
Asparagus Beetle Life Cycle
In early to mid-spring, as spears break ground, adult asparagus beetles emerge from sheltered areas along the ground and in trees.
The beetles mate and the females lay spare rows of dark brown, oval-shaped eggs on spears of asparagus plants.
Beetle eggs hatch in around a week and the small, translucent larvae start chewing on spears and foliage.
The larvae feed for around two weeks before pupating in the soil below the plants.
Pupation takes just a week, then the new adults emerge to start a new cycle. Cycles can last all season long.
Asparagus Beetle Damage
When adult beetles feed on spears, the spears turn brownish-green and the tips bend and look hook-like. Scarring will occur along the asparagus spears from larval chewing. The larvae and adults will continue to feed on the foliage all season long, weakening the plants and increasing beetle populations. The damage also weakens an asparagus plant’s immunity, making it more susceptible to fungal disease.
Managing Asparagus Beetles
Good timing and dedication are needed to remove these pests from your garden. Here are the removal steps that I recommend.
Look for eggs and beetles early in the season and daily as soon as the spears start to emerge and during harvest season.
Scrape off and smash the eggs, and pick off the larvae and adults and place drown them in a dish of soapy water.
Time your pest search well. Asparagus beetles are most active in warm, afternoon weather, while the best time to look for new eggs is in the morning.
Large asparagus beetle populations might need the addition of a pesticide. Neem oil is approved for organic gardening and has been shown to be effective on plants for several days.
Finally, harvest spears as soon as you can and snap them all the way to the ground to keep beetle food sources down.
“What kind of fertilizer should I use in my asparagus patch? What can I use to control the weeds in my patch?” Question from Linda of New Providence, Iowa
Answer: Asparagus is one of those spring vegetables that I think everyone should grow if they have the garden space. It’s so easy and so delicious. Here are some tips for easy weeding and care.
Asparagus Weed Control
When it comes to weed control, I always started by placing a wide cage around each asparagus clump to keep them upright through summer for easy weeding below. Staking and tying are two other options. Any caging or staking system will keep the rows looking good and make them more accessible for weeding. Then I add a layer of newspaper, wetted thin cardboard, or burlap mulch cloth along the sides of the asparagus rows and top it off with a thick layer of seed-free straw, leaf mulch, or grass clippings (sometimes all three). This step makes harvest less muddy, especially in moist springs, and keeps surrounding weeds down. Finally, I hand weed around my emerging spears. The use of a garden knife, or Hori Hori, will allow for effective precision weeding among clumps. If you don’t have a garden knife, it’s a good investment. Just be sure to keep Hori Horis out of reach from children because they are very sharp. I also recommend wearing strong gloves when working with one.
When it comes to fertilization, asparagus plants prefer balanced, low-nitrogen fertilizers (5-10-10), according to Stark Brothers, a good source for asparagus. I always used OMRI Listed fertilizer formulated for vegetables, which always worked well for me. I also like to occasionally add a layer of Black Gold Garden Compost Blend around the crown to act as a mulch and provide added organic matter.
“I’m looking for asparagus that will grow in USDA Hardiness Zone 10b.” Question from Lori of Venice, Florida
Answer: Asparagus generally survives in USDA Hardiness Zones 3-8 and requires a winter dormancy period to successfully grow and produce spears. In northern regions, plants can produce for up to 30 years, but they don’t tend to fare well down south where winters are warmer.
With that said, some varieties will produce spears in Central Florida, but they generally stay productive for just three to five years. One of the best of these varieties is the California-bred ‘UC-157’. (Click here for a good source.) This is the asparagus that you want to grow in your part of the world. To get special planting instructions for Central-Florida gardeners, visit the University of Florida’s page on the subject (click here to view).
Asparagus is one of those foods that when barbecued needs little flavor enhancement because the natural flavors are so incredible on their own. It tastes even better then freshly picked from the garden in spring.
For an easy and healthy vegetarian/vegan side dish for your barbecue, try this easy recipe for grilled spring asparagus.
1 pound fresh asparagus
1 tbsp olive oil
2 cloves minced garlic
The zest and juice from 1 lemon
1/2 tsp salt
1/4 tsp freshly ground pepper
grated Parmesan cheese to taste
Toss together all ingredients, making sure asparagus is well coated with garlic, salt, olive oil, lemon juice, and pepper.
Place on the grill and allow to cook for at least 5- 7 minutes, turning occasionally. The asparagus should be bright green and still have some bite.
Once off of the grill, sprinkle the grilled asparagus with lemon zest and Parmesan cheese. This flavorful vegetable also tastes great over pasta with chopped fresh tomatoes a drizzle of extra-virgin olive oil.