I honestly thought these things were bullet proof. I had 3 rhubarb plants (3 too many, daughter likes them) and for the season a small one that has been looking pretty bad just died. Now that the leaves have wilted I see that on the trunk of the flower stalk there is a good size hole; pulling said stalk reveals that whatever made the hole ate down the stalk and into the crown.
I’m being asked to do something for the other plants and my suggestion to remove them was shot down… I’m guessing this was the work of curculio beetle? They don’t seem to overwinter nor reproduce on the rhubarb itself; the plant growth destroys any eggs laid inside. What else could I do?
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thats interesting. there are rhubarb growing in overgrown fields here that were planted many decades ago and still growing. never heard or seen a rhubarb plant die of anything but extreme drought. how do you guys have curculio when ive never seen damage from them here?
Keep a closer eye on the remaining two plants and try to positively identify the pest.
This is basically me guessing, doing the plant version of a hypochondriac reading PubMed. Nasty hole on the side, whatever it was tunneled a hole down to the crown, and the plant wilted away.
Honestly the stupid plant is probably going to come back next year, this is rhubarb we are talking about :-\ But I will keep an eye on the others if nothing else out of curiosity.
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i agree. rhubarb is like its cousin comfrey. once you have its there for good.
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Pocket gophers killed my rhubarb when it was planted in the ground. Now I grow it in a container.
I don’t know whether you have gophers in Alaska, or some other kind of digging rodent?
After college, I spent a summer on an island off of MDI in the Gulf of Maine. There’s a big patch of rhubarb plants, 50’ wide or more, that’s been there for no one knows how long. It’s subjected to salt spray and hurricane winds and just keeps chugging along, spreading ever wider. Unfortunately, it had all bolted by the time the summer research season started, so no rhubarb pie.
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Maybe rhubarb stalk borer? It’s got to be either that or curculio. It sounds like it’s not the insect damage that kills the plant, but the rot that follows.
Rhubarb curculio and stem borer represent the two main insect pests of the species. Both insects bore into stalks and tunnel into the crown and root system. This damage also is a pathway for entry for crown rots. Since insect damage becomes evident as plants begin to wilt, infested plants should be destroyed. Also, wild dock, a close relative of rhubarb, growing in the area should be destroyed since it can harbor these insects as well.
https://ipm.missouri.edu/MEG/2016/3/Rhubarb-The-Pie-Plant/
- Rhubarb curculio is a dark-colored, snouted beetle about one-half to three-fourths of an inch long. It can bore holes into the crown and stalks.
- Stalk borers may cause similar problems as rhubarb curculio. Control them by removing nearby grassy weeds and curly dock, a weed that is the normal host for rhubarb curculio.
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Jay, you ever want some great rhubarb let me know. i grow canada red. its a sweeter more vigorous cultivar with huge leaves/ stalks. very tender. one patch is good for a family of 5. i could send you some root in the dormant season. its so vigorous i have to part it out or the stalks all jam in the middle. i have 2 patches of it and use maybe 1/4 of what grows. i give away alot to the older folks.
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I may take you up on that someday. I do have 2 varieties going right now: my wife’s family heirloom (I suspect seed grown rather than a named cultivar) and Gurney’s new “KangaRhu” which is supposed to be extra heat tolerant (and extra red). I’ll have to see how those two do.
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Ha! Y’all underestimate my ability to kill stuff. I’ve grown…or attempted to grow…in-ground or in pots, rhubarb, on at least 4 different occasions. Never had a single plant live more than one year.
Have 3 this year, each in 15 gal pot, 'cuz I didnt knowwhere my wife wanted them planted.
We’ll see how this goes…
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Lucky, mine were very sad looking at the end of the year last year. They looked dead, and I thought I had not watered them enough through a drought. But they came back this year and look awesome. I made sure to put a few inches of wood chips around them to stifle any grass growing and keep moisture in the ground (but damp, not saturated). If you have a setup similar to that you should be good. I think they usually prefer slightly acidic very rich soil.
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they are a cold weather plant. mine start to wilt at 80f. for you folks in warmer areas id mulch heavily to keep the roots as cool as possible. heat is rhubarbs worst enemy.
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That’s part of what convinced me to pull the trigger on geting KangaRhu. I’m usually not an early adopter of expensive, patented varieties. But the potential for harvestable rhubarb well into the summer was too appealing to pass up. I think they bred it with hot summer areas and folks like @Lucky_P in mind. It’s on its first year in ground, so I’ll see how it does. They sent a smallish tissue culture plant, so it might be a couple years before I get to try it.
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Yep. Mine is beginning to wilt down.
Jay, I’ll be interested to hear how KangaRhu works for you - I’d not seen that before… pretty pricey, but if it’ll survive… $29.99 for one plant is better than $20 for 3 that are gonna give up the ghost before a second growing season.
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one his matures enough all youll need ia piece of root from his plant. 
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I intend to give a full report when the time comes. Gurney’s has one of the most annoying price structures around. High prices, but they have a lot of “limited time offers” such as 25 off 50, 50 off 100, etc, that always seem to be on offer. So you can get close to 50% off (really about a normal, reasonable price) if you can find a good combination of items. People like to feel like they’re getting a deal, I guess. But I do have to admit they have some interesting exclusive items.
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thats their best selling point. something that isnt offered anywhere else. buying on sale like you did is the way to go. lets us know how it turns out. did they give you a good size plant at least?
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Sadly, it was pretty small tissue culture plant that clearly needed 2-3 more weeks in the greenhouse. And they sent it about 3 weeks before I’d expect a leafed out plant to be ok. I was able to nurse it along just fine, but a newbie gardener would probably have had a disappointment.
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Rhubarb is grown commercially here in the hot-summer Willamette Valley. Of course that rhubarb is regularly watered and harvested. At home, I get 4 harvest per year: late May, by July 4, then early and late August. If not regularly harvested, some summer stalks will dry out and become spongy. One trick is to harvest so that enough leaves remain to shade the ground. Rather than “bolting” (like lettuce), rhubarb (buckwheat family) sends up a bloom stalk. Commercial fields can have a lot of bloom stalks.
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