What To Do About Asparagus Beetles

What to do about asparagus beetles is simple: you remove and destroy them before they destroy your patch.
 
Asparagus beetles are one of the most common pests that attack asparagus plants and the good news is you can get rid of them with a mix of handpicking, good garden hygiene, and a few smart organic sprays.
 
If you’ve been noticing gray or black beetles crawling on your spears and ferny foliage, don’t panic yet.
 
In this post, we’ll cover what asparagus beetles actually are, how to spot the damage they cause, and the best ways to control them so your asparagus bed stays healthy season after season.
 
Let’s dig in.
 

Why You Need to Deal With Asparagus Beetles Fast

Asparagus beetles multiply quickly and they can wipe out your harvest if you ignore them.
 
There are really two troublemakers here: the common asparagus beetle and the spotted asparagus beetle.
 
Both feed on asparagus, but they cause damage in slightly different ways.
 

1. They Chew on Spears and Ferns

Common asparagus beetles chew on the spears you actually want to eat.
 
They also feed on the ferny foliage that grows after harvest.
 
Spotted asparagus beetles mostly attack the ferns.
 
But when the ferns get damaged, the plant can’t store enough energy for next year’s crop.
 

2. Larvae Do the Most Damage

The larvae of asparagus beetles are gray, slug-like grubs that feed on the foliage.
 
They strip the outer layers of the fern, which weakens the entire plant over time.
 
Larvae can defoliate a bed fast, especially when you have a heavy infestation.
 

3. They Lay Eggs on the Spears

Female asparagus beetles lay tiny dark eggs in rows along the spears and ferns.
 
Those eggs hatch into hungry larvae within a week.
 
That’s why spotting and squishing eggs early saves you a whole lot of trouble later.
 

Best Ways to Control Asparagus Beetles Naturally

Here’s how to get rid of asparagus beetles without reaching for harsh chemicals right away.
 

1. Handpick Adults and Larvae Daily

The simplest way to deal with asparagus beetles is to handpick them.
 
Walk your asparagus rows in the morning when beetles are slow and sluggish.
 
Knock them into a bucket of soapy water and dump it out.
 
Do this every day during peak season and you’ll knock the population down fast.
 

2. Encourage Natural Predators

Ladybugs, lacewings, and parasitic wasps all prey on asparagus beetles and their larvae.
 
Plant flowers like dill, fennel, and alyssum nearby to invite these beneficial insects in.
 
You can also buy ladybugs and release them into your patch.
 

3. Use Neem Oil or Insecticidal Soap

If handpicking isn’t enough, neem oil works well against asparagus beetles.
 
Spray it in the evening to avoid harming pollinators.
 
Insecticidal soap is another option and it kills larvae on contact.
 
Just be sure to spray the undersides of the ferns where the eggs and larvae hide.
 

4. Cut and Clean Up Ferns in Fall

Asparagus beetles overwinter in the dried fern debris.
 
Cut your ferns down to the ground after they turn brown in late fall.
 
Then remove all that plant matter and toss it in the trash, not the compost.
 
This one step alone cuts next spring’s beetle population way down.
 

Preventing Asparagus Beetles From Coming Back

Once you’ve dealt with the current infestation, you want to keep asparagus beetles from returning.
 

1. Keep Your Bed Weed-Free

Weeds give asparagus beetles extra places to hide and lay eggs.
 
Keep the area around your asparagus patch clean and mulched.
 

2. Rotate If You Can

Asparagus is a perennial, so rotation isn’t always easy.
 
But if you’re planting a new bed, put it far away from the old one.
 

3. Check Plants Weekly

Walk your rows at least once a week during spring and summer.
 
Look for asparagus beetles, eggs, and larvae before they get out of hand.
 
Catching them early is the whole game here.
 

4. Harvest Spears Promptly

Don’t let spears get too tall and ferny before you pick them.
 
Asparagus beetles love tall spears, so harvest while they’re still tender and short.
 

So, What to Do About Asparagus Beetles?

What to do about asparagus beetles comes down to staying consistent and acting early.
 
Handpick adults and larvae, spray neem oil or soap when needed, and always clean up those ferns in fall.
 
Add a few predator-friendly flowers and check your bed weekly.
 
Do all that and asparagus beetles won’t stand a chance against your patch next season.
 
So get out there, check those spears, and take back your asparagus bed one beetle at a time.