BURLINGTON, Vt. (WCAX) The asparagus is looking yummy! You know, there's something about these vegetables that as soon as they start looking good, other things come in to eat them. Other things think they look good, too, I guess!
Exactly, and for our asparagus patch, we have the asparagus beetle. The asparagus beetle is a little beetle that's either the common type or spotted one-- you have two kinds. What they'll do is they'll lay little black eggs that you can barely even see. They're just kind of hang down from their stems. Those eggs hatch into those little gray-green larvae that look little slugs. They'll start eating all of the ferns on your asparagus. So when you're harvesting, it's not an issue. But as the summer goes on, these ferns will grow up and you need to let them rejuvenate the root system or they'll get decimated. What happens over time is that defoliation by asparagus beetles will cut back on how many spears you'll get over the years.
So, it doesn't necessarily hurt the ones you are going to be eating this year, but if you want your asparagus to come back year after year, you need to control these beetles.
If you have just a few of them, you can let the birds and the ladybugs control them and it probably will be OK. But in this patch, we've got too many! So we're going to have to do something about it. The easiest thing to do is to come out early in the morning when the adults are out. The adults come out as soon as the spears come out. Just knock the adults into a pail of soapy water and that will kill them pretty easily.
For the larvae, you can spray Neem oil. Neem is nice because it's not toxic to bees, butterflies and wildlife, and it will kill all those larvae. So, if you can get on it early before the larvae really causes much damage, then you'll be able to disrupt the life cycle. You might have to spray again later in the season because sometimes they'll come back again, but by then, hopefully, you have a big forest of asparagus ferns and it won't be an issue.