Cardoon, concern?
I've been growing cardoon for five or six years now, hoping each year that the plants reach the size and impressive form of the ones I grew the first year. They behave as tender perennials here, or biennials -- sometimes making it through the winter, but usually not.
These plants have wonderful thistle-like blooms on them but since they don't flower the first year from seed, most years I don't see the blooms. I've actually only had the plants overwinter one time before, until this year of course. (This previous post is probably my best about cardoon, as it includes some old photos of those "better" years.)
Our mild winter seems like it should have guaranteed that all three of the plants I had in the ground would return in the spring, but it wasn't so -- one of them died.
This one though has come back strong!
It's putting up its flower stalk now too, which is expected but still exciting:
Hmm, something looks funny about that... I'll take a closer look:
Aphids!
Okay, I'm not panicing yet. There are large ants tending the little plant juice suckers, which is not surprising. I've never seen an outdoor aphid infestation that ants weren't involved with.
I at first thought the aphids were only on the flower stalk, but a closer look shows they're under some of the leaves too, causing curling:
Okay, maybe I need to do something about this. Maybe.
It may sound strange but I like to have a source of aphids in the garden. There are insects that feed on tiny aphids, and knowing I didn't have any good aphid sources in my garden would seem wrong somehow.
So should I react? Since I was heading out of town for a couple of days, I decided to wait and see. Perhaps the aphid eaters would help control the problem for me.
If not, I'll hit the aphids with a strong blast of water to wash them off the plant. If that doesn't get their numbers down to reasonable levels, then I'll reach for the insecticidal soap.
Aphids are usually quite easy to control, so I use only the gentlest of methods on them. I'd never resort to stronger chemical control methods with these pests.
I sure don't want them to damage the plant and reduce my chances of getting those blooms though...
Maybe I'll go get the hose now.
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Get the hose! Your cardoon will be thankful. And I bet you have plenty of aphids in places you can't see so I wouldn't worry about destroying a food source for beneficial insects.
I agree..."It gets the hose!" I usually don't do anything about aphids on most plants...figuring the same thing...they don't do any lasting damage, and they are a valuable food source for other animals. However, there are some plants they seem to really dessicate...so off they come!
Does hosing them off drown them or just wash them off and thereby sending them off to climb on nearby plants? I always wonder that when I'm hosing them off. Like you, I usually wait to see if they are controlled by other bugs. Sometimes I get lucky, sometimes I revert to hosing :)
I have bigger problems than aphids ... moles!!