Pest Damage or Overwatering???

I gave my elderly grandmother this Petunia a couple of weeks ago. It was doing well until the last few days. It obviously has pets too, which I sprayed for today. The most damage is to the leaves at the bottom of the plant stems- they are completely brown. Is all of this due to bugs, or is the browning and wilting because of overwatering? Thanks in advance for any help!
p.s.- the arrow is pointing to what I believe is an aphid cast. I was hoping it would be clear enough once I posted it, but it's not.

This message was edited Jun 19, 2014 6:10 PM

The damage to that plant is to the roots. As if there is air around them and they are damaged or drying out. The pot is clay and that sucks moisture out of the soil and keeps them too dry. The pot looks a little small as well, and you might have a better chance if the plant were in ground- or part shade...too much water would be yellowing leaves and pillbugs... remove the dead leaves and good luck.

That sort of wilted leaf and browning is due to over water.
Petunias need plenty of oxygen in the soil. Constantly keeping them wet excludes the oxygen and allows anaerobic organisms to grow. Many of these are bad for the plant, and I think this is what is happening here.

Get some new petunias, and add some perlite to the soil. Get her a water meter, too. Remind her that petunias need to dry out between watering more than some other flowers. Not bone-dry, but drier than many plants.

Thanks for the advice. I thought maybe she was overwatering. I can't keep her from doing it tho, she's getting dementia or alzheimers and does some really weird things and forgets a lot. It's been on a covered porch where it only gets morning sun. Anyone have any suggestions on a plant that will take a lot of watering and part shade?

UPDATE: This morning I caught a squirrel sitting IN the plant pot digging! I guess there could have been root damage after all.

I would have said overwatering also. But I'd like to add that at this time of year, petunias just don't want to play nice b/c too hot. When mine get like that, as your granny's, I reduce watering substantially and then let them be. Around September I give them a big trim, like two inches from the base of the plant and by end of month petunias are nice again and continue to be until the following spring. You are in OK, I don't know if the winter kills them, prob. yes.

Stupid squirrels can kill anything with their digging and not much you can do other than have a squirrel chasing dog and sprinkle lots of cayenne powder on any plant. (organic deterrent)

Plant for somewhat shaded or morning sun, and may get overwatered:
Impatiens, Begonia, Violet, Pansy, Coleus... other summer annuals for shade.

And plant them in something more like a cactus mix. Add lots of perlite to the potting soil.

Thanks for all the replies. Unfortunately I was not able to save it.

Diana_K: Thanks for the suggestions. I am actually trying the potting medium suggestion. We received (last week) a couple of peace lillies, african violets and a firecracker plant from my father's funeral. I am trying to keep granny from killing the peace lily and firecracker plant. I potted them both in a mix of pre-fab African Violet mix and Cactus/Succulent mix for good drainage. I also repotted all of them, and took a clump of the peace lily to keep in my bedroom for "safe keeping".

The darned squirrels are fearless because my two ancient dogs really don't have the gumption to chase them. One of them in particular (a squirrel) comes right up to my beagle and teases him into a chase that usually lasts about 10 feet. I have researched deterrents, and can't come up with anything that I don't mind the beagle eating. (He eats EVERYTHING. He even ate a whole mess of steamed kale that got spilled onto the floor!) I'm tempted to shoot the squirrels (I brought my "varmint gun" from home, a little .22 LR.) but I feel like it would be in vain due to the sheer number of squirrels in town. Any ideas, anyone???

Put the plants in a cage.