It's not fungal, or viral. The yellowing is tied to nutrition. It's called Interveinal Chlorosis. Here is the video on how to fix it and identify it: kzfaq.info/get/bejne/p8xynNebvt_KgGg.html

Yes, and no. Yes we need a longer petunia, but not a Supertunia. There are growth habit differences between Supertunias and true trailing petunias such as Surfina Pink Vein. Supertunias were bred to sprawl out across the ground and don't make good baskets. Their branches tend to stick straight out. Petunias like Surfina Pink Vein are true trailing petunias and if cared for correctly can trail 4 foot or more. kzfaq.info/get/bejne/mKuflLZix57Vk30.html

​@@AgTeacherThoughtsOhhh I didn't know they grew like that, thanks for letting me know

Petunias tend to be the tanks of the garden. Typically they do not care if they get wet. However, with this one it does seem to be a little more sensitive, probably due to the varietal choice. The internode spaces are small, and the leaves tend to shadow one another which makes them susceptible to moisture related issues. I have also noticed that some grow lights are a bit too strong for plants. I've had some seedlings that struggled with the intensity of the lights. If you have a place outside, and a sacrificial start try growing one outside to see if it performs better there for you.

I can certainly give you some ideas. First of all, we have to consider the size of the container it is currently in, and the type of potting soil. For the container, once you receive your plant it needs to be transplanted into a container no less than a one gallon nursery container. These are pots about six inches across and ten inches deep. The soil should be a peat moss and pearlite mix. I recommend Sunshine Mix Number 4, which can be found at either Lowes or Home Depot. After the container, we need to think of watering. You should water it daily with enough water to ensure it runs through the pot. A decent size pot should be able to hold enough water for a whole day. Next, let's consider your climate, if the temperature is above 90 with low relative humidity you may need to water morning and evening.

@@AgTeacherThoughts All very useful information. I replanted them yesterday into deeper gallon pots - they were in ceramic- with the sunshine mix you recommended. It's only 68 here today, so even after 1 thorough watering it's still damp next day. I'll water again tomorrow and see how it goes. Took a picture after replanting so it will be possible to judge if they are getting bushier. Thanks so much for the help

Fertilizer: Jack's Classic Petunia FeED 20-6-22 at a rate of 1 Tablespoon dissolved in 1/gallon of water. Water it with fertilizer water every watering. As far as the seed, I do not know on this variety what method they use for pollination. Mine is outside so there are plenty of options for bees to pollinate it. I also have many petunias near by, so it could be set via any method. They do set seed, but propagation in any form is prohibited by law as they are patented.

I'd need to see a photo or have a description of the damage. Can you describe the size and shape of the damage? Is it just on the leaves, or blossoms, or stem? Is there any evidence of Frass (droppings) or slime trails? I have videos on Thrips, Aphids and Budworm. Each of the videos describes the damage and how to combat the pest.

@@AgTeacherThoughts its circular holes on the leaves and blooms similar to what ive experienced with other garden plants like cucumber or squash. mostly just general leaf damage. No slime trails or black spots or poops noticeable. even though im not able to specifically identify the pest i believe it to be beetles of some kind since that is what ive seen in the yard in the past. im not able to keep whatever it is off these things. edit: i went ahead and just moved them. maybe they are the tastiest thing in their area and i got them up off the ground i think this will help a little.

There are a few things that cut circular holes. In petunias this is most often Budworm. They appear early in summer, and start with holes and eventually as the caterpillars grow, they will eventually consume the entire blossom. OR it could conceivably be Cutter Bees. They cut and remove sections of leaves and blossoms to build nesting chambers. They nest in hollows of wood or old plant stems. Cutter bees are great pollinators so I wouldn't fight them. You can fight Budworm using a biological spray called Bt. Here is a video on that: kzfaq.info/get/bejne/fpxmaqqZx6nVnnU.htmlfeature=shared