Answer: Hanging baskets may need more frequent watering than twice a week, depending on the weather and on how crowded the plants are in the container. Use your finger to dig into the soil and check it. If it is still damp, do not water yet. When it feels dry, water slowly and thoroughly to moisten all of the potting soil in the pot. Then empty the saucer of any excess water. By midsummer when the weather is really hot you may need to water twice a day.
If the soil has dried out completely, you will have to set the pot up to its rim in a container of water for a few hours or so and allow it to soak up some moisture. Add a drop or two of dishwashing soap to the water to help reduce surface tension.
Petunias should be deadheaded regularly, meaning remove the faded flowers. Be sure to remove the bulge at the base of the petals so you get the whole flower when you do this. By midsummer or so the plant may seem leggy and thin. That is when you would trim it back by about a third or so to stimulate new growth and branching so it will stay vigorous until fall.
Very young plants are pinched to stimulate branching early on. This is just removing the growing tip of each stem. You can use a scissors or literally pinch the tip off with your fingers.
Q&A Library Searching Tips