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Delphinium question

Posted by marciaz3 Tropical3/NWOnt (My Page) on
Thu, Jun 24, 10 at 23:40

A friend has shown me her delphinium leaves, all eaten and ragged. She thinks it's slugs, possibly, but i remember reading a couple of times that there's some other kind of bug or pest that attacks delphs. I don't have a problem with mine, so i didn't pay attention. Can someone refresh me?

Thank you!


Follow-Up Postings:

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RE: Delphinium question

  • Posted by marric Z5a Ontario (My Page) on
    Fri, Jun 25, 10 at 8:53

That sounds like what is happening to some of my plants. My poor astrantia is tattered. They are even going after my marigolds. I think it's earwigs - we have a lot of them this year. They seem to prosper in wet years. Something seems to like all this wet weather!


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RE: Delphinium question

I have the same problem here in N/E Ontario with some new delphiniums. Earwigs have one of them stripped of every single leaf. Any thoughts on the best method of "extraction"?


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RE: Delphinium question

  • Posted by xaroline zone 3 Calgary Canad (My Page) on
    Fri, Jun 25, 10 at 9:47

Here in Calgary there is a moth which damages delphiniums.
We either spray the young plants with a pyrethrum based rose spray or we cut the plant back if damage appears. They will then grow new healthy shoots after the moth's cycle is over. And flower a bit later.


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RE: Delphinium question

Mine get defoliated so badly by small green caterpillars I almost stopped growing them. I don't know if they are sawfly larvae or something else, but for some reason they didn't have any this year and look beautiful. The caterpillars are the same colour as the leaf and work quickly so they're hard to trap and squash.


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RE: Delphinium question

She put beer out for slugs and has found some, but her delphs are still being eaten, so maybe it's the sawfly larvae.

She has also found what looks like a tiny cutworm on her tomatoes. Some years you can't win with pests, eh?


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RE: Delphinium question

I know the answer to this question!
I know the answer to this question!

I just can't retrieve it from my brain...........

I just read somewhere the other day about this. I'm pretty sure sawfly larvae work their way up to the flower buds and stay there. If you cut the tops off your plant, you'll get rid of them and the plant will come back beautifully. Mostly I remember thinking if there's a problem, cut them off.

Where on earth did I store that information???

I better go outside, if I can fight through the mosquitoes, and see how my delphiniums are doing =:)

Good luck with yours


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RE: Delphinium question

Yeah but if she cuts them off, she doesn't get any flowers! :(


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RE: Delphinium question

My thoughts too - but in previous years the little buggers were so bad they ate the flower buds before I got there anyway. The best way to get rid of sawfly larvae is wear gardening gloves and squash them with your fingers. I wonder why I don't have any this year... hmmm.


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RE: Delphinium question

Marcia, My delphs get little green worms every spring. If you watch you can see the leaves start to curl. The worms are in the curled leaves. We pick them off by hand and do the squish worm dance. We have to go through the delphs 2 or 3 times each spring. If we don't the leaves get devoured and look really sad, what doesn't get eaten looks droopy and sad. If you catch them and hand pick, the plants will be fine.

There was one plant this year that we didn't get to on time. I just cut it back.....and it regrew nicely and has almost caught up to the rest.....and it is going to bloom too.

A few years ago we were away and we had a big storm. When I got home my delphs that were in bloom were flattened and many broken and split stems. I cut them all back right at the ground, had no choice......and they all recovered and bloomed again in the fall. Delphs are pretty tough. I wouldn't want to do this every year, that would probably weaken the plants....but it didn't harm then that one year.

Good luck to your friend.

Sierra


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RE: Delphinium question

2 environmentally caterpillar killers are

Insecticidal soap will kill caterpillars if you spray them with it

Pyrethrins: Leaf-eating caterpillars can be controlled by sprays containing pyrethrins, the active ingredients extracted from flowers of pyrethrum daisies. Pyrethrins break down in a few days in the environment and are less disruptive to the natural enemies of caterpillars than most synthetic pesticides.

Products containing pyrethrins mixed with insecticidal soap are also effective.


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RE: Delphinium question

Thanks, all - i'll send this thread to her and she can start remedying!

Sierra, i've never had a problem with my delphs, except for getting flattened by rain. If that happens again, i'll remember your advice. I have had sawfly larvae on roses, though. I was just picking off the buds they destroyed, but now will get out the insecticidal soap for them.


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RE: Delphinium question

It's most likely the delphinium worm. If you see the damage, you can unroll the leaves and pick then off by hand or simply cut off the foliage and let the plant regrow from the base. The moth has only one cycle during a season so it won't reappear until next year. Sprays don't really help as the worm is quite protected by the leaf.

They don't do any real damage in terms of health to the plant. They do however tend to eat the flower bud.


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RE: Delphinium question

I found the article about delphiniums I talked about.

It's in The Gardener For the Prairies Magazine, Summer 2010. It talks about sawfly larvae (not specifically on delphs) and also the Delphinium Leaf Tier (pronounced tire). The moth causes tip deformity and the caterpillars can be found in the curled up leaves. Once the caterpillars are in the tips, they stay there and you can cut off the top 3-4 inches . Apparently they'll still bloom as if nothing happened.

This may or may not be your friend's or others' problem.


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RE: Delphinium question

Hello,

Some of the Delpiniums in my garden have very misshapen spires. The stalks are thick with many smaller stems with small green flowers about an inch in diameter. They are very green with a white center. They do not have the tall flowered stalks of other plants. About a month to six weeks ago, the neighbor hired a small spray rig to hit the weeds in his yard. It was early morning when you would not expect air movement, but there was a drift.

Since all the plants are not affected, just two plants which could have experienced some drift, I am thinking it is herbicide damage. The plant seems to have grown out of control, not taller, but with unusual growth in the manner described. Does this sound familiar in any way?

Darlene Grove


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RE: Delphinium question

When you said thick stalks, it made me think of faciation. I've had that happen on some lilies - thickened stalks and and an abnormal amount of blooms.

Not sure about the herbicide, though. Maybe someone else can comment on that.

I read through this thread and still have no clue about who it was with the delphinium problem. Sad, eh? LOL


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RE: Delphinium question

Darlene, I agree with Marcia, delphs are prone to faciation which is an abnormal overgrowth of stems &/or flowering parts. Sometimes the flowers will be vegetative which is the greenness you're describing.

Herbicide drift can also cause strange growth if the plant is hit but not killed. I think it would be pretty difficult to prove either way. Either way it's temporary so if you prune off the bad parts the plants will re-grow and probably bloom normally later this summer.


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RE: Delphinium question

My delphiniums are about 6 feet high this year and absolutely gorgeous until a few days ago.

The bottom leaves are wilting and turning yellow.

Is it possibly the heat and humidity, or overwatering, or something else? I've given them quite a bit of water in the last week or so, as it's been hot and humid. There doesn't appear to be any insect or worm damage.

Thanks!


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RE: Delphinium question

I'd forgotten about this thread and still have no clue who it was who had the problem with her delphs. LOL But this year i have large black beetles (about an inch long) that are eating my delphs. As mentioned in another post, they are now enjoying their time at the "gas-spa"!


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