If you bought it at the garden center, brought it home and wheeled it out into the sun, you are frying it. I am into full blazing summer sun here. I still plant but I have sunscreen hats that new plants wear until they get their feet in. Wheel it over to morning sun until it adapts to being out in the wilds.

unfortunately this wheelbarrow is very unstable, and in fact, the handlebars are completely rotted off of it. I'm surprised it's even able to hold up to the weight of the river rock and dirt.
Is there anything I should do to protect from the sun since I can't really move it? It hasn't been getting overly hot here in Ohio yet....mid-70s to low 80s. Pretty cool at night still (mid-40s to mid-50s).
Also, did I use the right soil by just filling the wheelbarrow with Potting Soil?
Also, should these type of plants be watered daily?

drink from above?

Petunias always look raggedy when they're rained on. Give it time. There's no reason why it should not look as good as it was. Watering? You'll get mixed opinions on this, but they don't like constant wet soil. They ordinarily thrive in drier conditions...at least they do for me...when planted in the ground and not hanging baskets. Your situation is similar to being in the ground.

It's always a good idea to loosen any root bound plants, but I think it's overhead watering that's the cause. Some flowers could be just fading as well..look for others to come out and please you.

lack of water.. period..

i see it in the dullness of the green ...

and i would bet.. it was about ten times to big.. for the pot it came in ..

when i choose plants.. i look at the ginormous ones.. and then pick small plants with one flower .. to insure i get what i want.. but to avoid buying overly mature plants that will not take the transplant as easily ...

water it deeply and thoroughly.. and put the whole in shade for a week.. it will probably bounce back

in a sense.. you went for immediate gratification.. while i go for potential ....

ken

I'm not as familiar with wave petunias, but on regular petunias, each flower only lasts a day.

I know that the surface of the potting medium appears to be bone dry, but what does it feel like when you dig your fingers in a few inches?

It does look a bit lonely in there all by itself, lol.

Well, I wasn't sure how much 1 Wave Petunia would grow, so I was just gonna try one to start.

If it is the regular wave petunia, it grows flat and will cover the soil in not too long. Easy Wave, a little more mounding. I buy them and had one mostly eaten by the slugs and it came back. They are tough. You can give it some shade by putting a board over it held up by plastic pots. That would block the noon sun and it could have morning and afternoon sun. To begin with it will take a bit more frequent watering because it's roots are in the top part of the soil in a tight little square. Once it can get a root to the bottom of the container it will be resilient. It is stressed and it needs babying for a short while.

Wave petunias do tend to grow closer to the ground. When translating mine, I usually water daily for the first week...the a few times a week afterwards (I know that's more often than some, but mine like it that way). I do try to not water directly on the blooms, since they are so fragile. I think it will perk up if you keep up. :)

I slow watered it yesterday night by poking a small hole in a plastic drink cup. Today the plant seems to have perked up and there were new blooms on it!
:-)

Since you can't move it, try just draping a piece of light weight fabric over it until the roots grow a bit and it's acclimated.

Thanks for all your responses! It's actually been blooming pretty regularly now....it just doesn't seem to be trailing as quickly as I thought it would. It actually doesn't look like it's grown much at all. I thought it would quickly grow downward of the slope of the wheelbarrow and flow over the front. Maybe I am just too impatient!