Hi, comfortdog,

In the times when aphids or other insects are a problem on my zinnias, I use a systemic insecticide containing Imidacloprid. I usually apply it as a drench rather than as a spray, to avoid problems with spray drift. It is absorbed by the plant through the leaves, as a foliar application, and the runoff from the leaves is absorbed by the plant through the roots.

Since it is systemic, it is in the sap of the plant which the aphids suck, which gets them effectively. Any insect that feeds on the plant, by sucking or chewing, is controlled.

Systemics have several advantages besides avoiding spray drift. Rain won't wash them off, because they are inside the plant. And new growth is protected as well, unlike surface sprayed materials. Obviously you would not apply Imidacloprid to any vegetable or fruit that you planned to eat. It is strictly for ornamentals, non-edible-bearing trees, grasses and such.

Imidacloprid is an ingredient in many garden products. The one I use most is Bayer All-In-One Rose and Flower Care. It also contains a systemic fungicide and foliar nutrients. I use it on my favorite "breeder" zinnias (I am an amateur zinnia breeder).

ZM
(not associated with any product or vendor mentioned or linked)

Another problem associated with Imidacloprid is that its use can cause a secondary infestation of spider mites on treated plants.

Comfort, please be more specific about what you've used. I'm sure that you didn't mean to say 'fungicides ', which would be totally useless against aphids. As for the soap sprays, did you use commercial insecticidal soap or a home-made concoction?

Of all of our usual garden pests, aphids are usually the easiest to control.....but it takes persistance, the right techniques, good cultural practices, and patience.

i wish i knew where you are.. but everywhere.. it will be sept next week ...

THROW OUT YOUR ANNUALS ... including all soil ...

though i have no aversion to systemics.. what is the point of spending money on something that has shot its wad for the season .. what.. for an additional $20 investment.. you will get a few more weeks out of your $10 annuals???

while you have the pots empty ... bleach them out..

sterilize some new potting media ...

and start fresh ...

since you will be throwing out ALL annuals.. then you will be no residual aphid problems ... clean up this weekend... buy mums.. next weekend ... aphids will not hang around for a week ....

ken

Now, you might be using Neem oil, which can be used as a fungicide, an insect anti -feedant, and insect growth regulator.

A good scrubbing with the hose water is really all that is necessary. Allow the containers to dry in the full sun....ken may disagree with me, but he tends to be a bit of a germaphobe. :-)

Good luck with the mums! Inspect for aphids when you deadhead....squish when you find them.

Trying to get rid of every pest you see is really counter-productive. Sure, don't let something as easy to combat as aphids ruin your plants, but there needs to be pests for beneficials to show up. Whatever chemicals that might be harmful to aphids are also likely harmful to whatever predators that may have started working on the problem, as well as the 'good' wildlife mentioned above.

I think aphids are somewhat host-specific, meaning that aphids that like petunias may not necessarily find mums palatable. Rhizo will correct me if this is wrong, but if it's true, she's probably my source of this info.

There is a Chrysanthemum aphid, also exclusively host specific. But I have no idea if any of the free agent aphids out there will feed on them, as well.

I really do this, with the ladybug larvae, helpful little eating machines. They're not very smart or thorough, maybe easily distracted, maybe got eaten by something mid-shift, not sure which, but very effective right where I put them. Maybe I didn't make it clear yesterday I wanted the whole vine cleared before moving on, or something else... another tip on this vine could use a visit from one of these, but it would be a monumental crawl for the tiny helper. Anyway, this is a lot easier than trying to wash the aphids off (don't want to add any extra water to the ground right now,) or squish them on tender rex Begonia vine (Cissus discolor) without squashing the fragile/succulentish vine and delicate tendrils, flower buds. The little eating machine just cleans the vine with no damage at all. It would also be possible to snip the tip and just smash it underfoot, if I felt like it. It would grow back quickly.

There are a lot of easy ways to deal with a few aphids. I don't see them spreading to other plants when I do nothing at all. A lot of plants have had problems in this summer of way too much rain. Weakened plants with mushy, rotting roots are exactly the kind pests like.

The last petunia to die here this year was in a big mixed pot with other plants. The other plants are still in the pot, doing great (Pentas, heliotrope, purple heart - Tradescantia pallida if curious.) Petunias are fussy diva plants that always want more sun than you have, or less, or more water, or less water, or more fertilizer, or different soil PH, or something. Sure there are great ones every year, but of all of the plants sold as annuals, few come close to petunias for being impossible to please. I've bought some every spring for like the past 25-30 years and don't recall ever seeing one killed by frost. I'm sure it happens, but I gave up expecting such in my yard a long time ago. Happened to get one through to fall a couple years ago and put it in the ground. It showed back up the next spring, then died mid-summer, like all of the others. I'm convinced they like spring, but not summer. The patches of wild white/light pink ones are gone by now too, no longer a roadside attraction.

I commend you for not having to decide yours officially look terrible until so recently, Comfortdog. Are these pots the hanging kind? You may like Calibrachoa for a similar look next year, if longevity is worth smaller, unscented flowers in your book.