Asparagus Beetles, Part 2 —Tips to Prevent an Infestation

Photo credit: U of M Extension Service

I recently discovered asparagus beetles in my garden…and a great website from the University of Minnesota Extension that shares what you can do about them.

If you do find these unmistakable spotted buggers in your home garden, you can hand-pick them. Since I’m an old hand at bug-picking, I had no problem with hand-to-hand asparagus beetle combat. 

(More in my April newsletter, the Little Farm Horror Movie, including my free mini-ebook about tent caterpillars.)

Keep in mind, however, that capturing the beetles is not a one-and-done operation. Like with tent caterpillars, you may need to pick the beetles all through the insects’ life cycle. 

For asparagus beetles, that could be the length of the growing season.

The U of M Extension people recommended tossing the beetles into soapy water, but I’m allergic to almost all soaps and detergents. So as soon as I went outside, I poured a small amount of apple cider vinegar into an empty yogurt container, added an equal amount of water.

Prepared for the long haul—i.e., all summer—I clambered over the rabbit fencing into the asparagus patch started in.

There were a LOT of beetles. Although they’re small, I wondered how could I have missed them before. And worse, these beetles can fly!

Which complicates your capture; you’d reach for a beetle and off they’d go. It reminded me of days of yore, when wily caterpillars would wiggle away just as you tried to grab them, and they’d fall into the grass where you couldn’t see them.

But on the plus side, these beetles aren’t in the least bit squishy, so a win.

The website said to pick in the afternoon, while the bugs are most active. So I spent about 20 minutes picking in the middle of the day, make another turn around the patch in the early evening, then one last pick shortly before sunset.

I probably got 30 or 40 bugs that first picking, and put a lid on the container before I quit for the night. The next day, upon fetching my container, I discovered the beetles were still swimming!

Okay. These guys were tough. Stronger measures were required. I got another container, poured in a measure of full strength white vinegar, and went at them.

Asparagus beetles chewing on my veggies!

With all the stalks they’d damaged, many shriveled and inedible, I found a strange satisfaction in picking these bugs. I felt even better when I got a two-fer: grabbing two beetles as a time when they’re engaged in…um, making beetle babies.

So for four days, I picked three times a day. Then the next four days, I picked twice a day. I think by now I’ve caught a couple hundred of them.

And you know what? It works! After my intensive picking, I've been finding only one or two in the patch, then after that, nothing!

However, I’m keeping in mind that I might have just picked the first generation of beetles, and their life cycle could be starting all over again. But here’s the beauty of keeping an organic garden:

Helpful pests!

I’m not crazy about all the ants we have everywhere--in the garden, in the  yard, and in the woods. But when I found lots of beetles on an asparagus stalk, I also would find loads of ants busily working over the stalk too! My guess is, the ants were feasting on the beetle eggs.

With the beetles gone (for now, and fingers crossed for the rest of the summer), the spears look healthy and robust again. New tips are pushing out of the soil every day, just as they should. Because of the earlier damage, I’ve only harvested about half or even a third of the number of spears I normally would. I want to make sure the crowns keep their vigor.

Healthy spears again!

So the asparagus patch will be thick with ferns this summer. It’ll be more difficult to weed, that that’s a trade-off I can live with!

I’ll keep inspecting the beds—as I indicated above, I wouldn’t put it past these beetles to create at least one or more generations over the summer. I didn’t exactly need yet one more garden job, but there you are.

I did learn one more crucial beetle management tip: Maintain your asparagus bed in the off season.

Over the winter, you must clear all the dead foliage and other debris. Leaving it in the bed provides shelter for overwintering pupa.

So as it turns out, my bad. This past winter, the foliage stayed vigorous, right up until the first of a series of severe Northeasters here in the Foothills. So I didn’t clear the asparagus bed until March.

Still, after all this bug-picking this summer, you can bet the entire area will be clean as a whistle next winter!

If you enjoyed this post, you can find more about homestead-style gardening and “homesteady” living in my monthly Susan Colleen Browne newsletter—it's free and open to all, so there's no need to subscribe to read it…

The latest issue: "Homestead Diary & A Tale of Two Irish Movies." I hope you’ll take a look!

~Susan

Trouble with Asparagus, Part 1

Asparagus is super easy to grow for the home gardener. Once the crowns are established, keep your bed weeded, give it lots of compost in the fall, and mulch it well for the winter. By mid-spring, you’ll be rewarded with a bountiful harvest!

But while very hardy, asparagus can be vulnerable to pests. In my garden, I just discovered a very destructive one. The good news is, the remedy can be simple! 

Read on for more about raising asparagus…

Ten days ago, my asparagus crop looked terrible. And it seemed to look worse with each passing day.

The first spears of the season are normally very robust. Starting around the first of May, the smooth asparagus tips are vigorously pushing out of the soil, greenish white and purple-pink around the edges, the spears a healthy dull green.

Not this year. The tips were curled over, and looked like they’d been chewed on, exposing the tiny buds that should turn into ferns. The stalks seemed to have tiny bites taken out of them. And whole spears were turning yellow and shriveling. 

Slugs?

Slugs are the usual culprit at our place when it comes to damaged asparagus. Only there were two problems with my slug theory: first, this month has been so dry I’ve seen exactly one slug in the yard instead of hundreds. And second, slug damage will affect individual spears, one at a time.

Slugs eating spears here and there doesn’t affect the vigor of new tips emerging. And at the beginning of a normal harvesting season, sometimes I’ll be picking 20 spears each day. And more on hot days.

What was odd about this May’s crop was that the entire crop seemed slowed down. There would be maybe seven or eight spears of harvestable size each day, all of them damaged.

It didn’t look like slugs, but I sprinkled some suitable-for-organic-gardens iron sulfate around the bed anyway, like a moat.

The next day, I was in the bed for more discouraging harvesting, when I saw two black and red spotted bugs about 1/8 of an inch long, parked on a small leaf next to a spear.

I’d read about pests that attack asparagus, but didn’t pay much attention. I’d never had a problem all our years raising asparagus. But now, I had to do something; my formerly vigorous crop was shriveling right before my eyes!

As soon as I was inside, I Googled asparagus beetles.

The first prompt was “Asparagus beetles in home gardens.” I clicked on it, and pulled up the University of Minnesota Extension site. I was raised in Minnesota, so this was my lucky link...

Photo: University of Minnesota Extension

Well, BINGO. The U of M Extension photo showed beetles that looked exactly like the pair I’d just seen.

On the site I discovered pretty much everything a home gardener would need to know about asparagus beetles. I’d already seen the beetles can wreak a lot of havoc. But I learned the damaged spears won’t develop properly into the fern stage, when the crown is rebuilding over the summer and fall months. As a result, your crowns can be permanently damaged.

Still, an organic remedy for an asparagus beetle infestation is simple...I'll be back next week for more about how to manage this pest!

Until then, have a wonderful week, and I hope you get to spend lots of time in your garden!

~Susan

Homestead Gardening Class and Free Gardening Book!

 “Grow a Homestead-Style Food Garden,” my community college workshop, is happening next week, September 28! We’ll cover lots of sustainable gardening techniques, as well as composting and natural fertilizers, and a handy timeline for your gardening activities throughout the year.

Accessing all the class information is easy…because all the course content and more can be found in my free ebook, Little Farm in the Garden. And speaking of…

People must be getting ready for serious fall gardening…I’ve just discovered this Little Farm book is having a moment!

The book was inspired by the aforementioned homestead gardening class, held every fall and spring at the community college. www.Whatcomcommunityed.com

Writing Little Farm in the Garden was hugely fun—a way to share lots more information than I can fit into a workshop. You can get the Amazon ebook by clicking on the cover on your right!

And if you don’t mind me tooting my own horn, here’s the latest from Amazon’s gardening best sellers…

And below, in another category…

Berryridge Farm has gotten short shrift this week—I’ve been madly finishing up my latest Irish novel. And this afternoon, a flurry of urgent family emails showed up.

But I’ll post some new garden pics soon! PS, if you prefer to read on your computer, you can also get a free PDF of Little Farm in the Garden at my website, www.susancolleenbrowne.com