Friday, September 3, 2010

Missing Some Sunflowers? Here's Why (SOB)

Last year I mysteriously lost dozens upon dozens of Helianthus 'Lemon Queen' blooms. I'd walk out there expecting the glory of yellow and see tons of dried up, flaccid, poop-brown blooms. And same thing this year. It's the black sunflower stem weevil, or black sunflower head clipping weevil. The weevil cuts sunflower heads off the stem a few inches below the bloom, and just as it's about to flower. The cut is so clean you'd swear some punk teenager walked by with a scissors or his green beret dad's machete.

On larger stems the cut is even crisper than this




















Mr. Weevil (apion occidentale) isn't considered enough of a sunfower crop threat here in the Plains to treat by commercial growers, but for those of us with one perennial sunflower--and a few seed-planted yellow and chocolate annuals--it's like aramageddon.

About the size of a pea













I've finally caught 3 weevils, all in the morning, sitting snuggly in the limp and freshly cut bloom--until I smoosh them good with mulch. Adults overwinter in stems and leaf litter, emerge in late spring, and eventually migrate to lovely gardens like mine. These adults lay eggs, and then a fresh batch of adults come out in August, just in time for the helianthus blooms.

Why do they cut the stems? To lay eggs in the bloom which falls on the ground. And to make me cry havoc and let slip the dogs of war. Now you know, and knowing is half the battle (that, folks, was Shakespeare and G.I. Joe working in elegant tandem).

8 comments:

scottweberpdx said...

Nothing infuriates me more than that sort of thing...when a plant is JUST about to bloom and gets the smack-down. This year, it was a heat wave and high winds just as my 'Raspberry Wine' Monarda was about to bloom...crash-boom and a dozen stems were snapped and blown down the street along with a smattering of Verbena bonariensis. Seriously, though, there are few things sadder than a big, bloomless stalk in the garden...it's like you've been cheated out of your just rewards :-( You have my condolences.

Liza said...

Smart little buggers, aren't they?

Kyna said...

I would be so pissed off. I can just picture you swooping down on the weevils, sword brandished...lol

Rosey said...

Sometimes there needs to be some violence in the garden. I am going after a pocket gopher that has a voracious appetite for my yellow squash today.

It seems depressing that they can come back in the spring. I would hope that the little weevils would just die off completely. Yes, I sound like such a nature lover. Shh...don't tell.

Shyrlene said...

SOB doesn't even cut it! Little snarky bugs with ravenous appetites just suck! Smushing the bejeebers out of them helps with anger-management, but when you have an infestation - is chemical warfare the only hope? (Cottony Maple Scale was our dilemma this year...)

Kris said...

Omigosh now I've got to run out and apologize to half-a-dozen squirrels! (Sorry guys, sorry, sorry, sorry....!)

Benjamin Vogt said...

Scott--That is my favorite monarda! Luckily, the wind hasn't broken things here for three years, which is a minor miracle.
Liza--Not anymore. They dead.
Kyna--Sword? More like grenade. :)
Rosey--Being a gardener is living with irony and dichotomy--being human, but more human than human, perhaps.
Shyrlene--I'm VERY hesitant about chemical warfare, and when I do use such tings (mainly for grasshoppers) I try to use as insect-specific a poison as possible instead of reachign for Home Depot's gallon of death products. Last year aphids and grasshopper, this year lady bugs and a wet spring helped ease those both.
Kris--That's what I though, squirrels or rabbits. I mean, an insect can't cut through a 1/4" stalk, can it? Yes it can. And more.

Rob (ourfrenchgarden) said...

Bet you're on first name terms with these little fellas, 'hey weevil, f*ck off'.

I see them over here and dutifully pick them off and chuck them into a cup of water. It's the grubs I fear, chewing through roots like there's no tomorrow.

May you prevail.