Cutting petunias 'way back is SOP (standard operating procedure), as far as I'm concerned. I'm going to give mine a severe haircut today! Be sure to keep them amply fertilized.

Really? Like how far back do you cut them? Do your leaves appear yellowish?

What exactly do you mean, fertilized? Like Miracle Grow?

Petunias, like most annuals that are prolific bloomers, require frequent fertilization in order to keep them supplied with the raw materials to make all of that energy.

I always incorporate a slow release product upon planting, but also boost with low doses of a soluble fertilizer, too. I use a tomato fertilizer on my flowering plants as it has less nitrogen and more phosphorus.

Nope, my plants aren't yellow.

I have one container filled with petunias, and have just returned from cutting about half of the stems back to about 6 inches. In about a week or so, I'll cut the remaining stems.

Could be all that rain washed away their fertilizer, leaving little, explaining the yellow. If they were leggy, it could be from lack of sun (blocked by all those rain clouds). One spring we received a lot of rain for our area (6 inches) and many vegetables in the garden (especially the green beans) really went yellow. I fertilized and soon they bounced back, but it took a while, since it was so wet that things had to dry up before I could water in the fertilizer!

k

Cut them back to about 8 inches. Feed them an iron rich fertilizer ( I use a cup of ironite granules mixed with 4 gallons of water). It will take about 2 1/2 weeks and you will be happy you cut them back. They will be healthier, bushier and loaded with flowers.You dont have to wait until mid-summer to cut back. your petunias Often times, petunias get leggy by mid-june. This is particularly true when they are potted and watered too much.

Here is a video for you guys also with tips to avoid or recover from shock.. lol

Cheers~

Izhar

Here is a link that might be useful: Rejuvenating Petunias