With only a bit of effort, you can keep your Wave petunia hanging baskets blooming with masses of bright color all Summer.
Use a basket with good drainage. Fill it with a lightweight potting mix and add in a slow-release fertilizer at planting time, then feed every week or two with a water-soluble fertilizer for annuals.
Petunias are perfect for locations exposed to full sunlight. If you plant doesn’t get enough sunlight, it won’t thrive. And make sure to rotate the direction of the pot. The plant will tend to grow towards the sun, so once a week you can turn the pot so that the shaded side can get sunlight.
Watering is essential for keeping your petunias blooming. One way for you to test the dryness is by the weight of the pot. If it feels heavy, you should have sufficient water for the time being. You can also stick your finger in the soil and pull out a small amount. If you can roll the soil into a ball and squeeze water from it, you have too much water. If you can’t roll it into a ball and it blows away, you need to water it. The perfect soil will roll into a ball and will not release water.
Water it some more
Hanging petunia plants may need water daily during the Summer, and maybe even twice during periods of extreme heat. Water deeply, then let the pot drain. Never allow the soil to remain continually wet, as your petunias are likely to rot in soggy conditions. If possible, water the soil and not the foliage, as wetting the leaves can promote fungal disease.
Remove wilted flowers when they fade. Although Wave petunias do not need to be deadheaded to promote flowering like other petunias, cleaning off spent blooms gives a more professional appearance to your baskets and containers. Cut petunias back by about half if they look tired and scraggly in mid-Summer. This will stimulate the growth. The rejuvenated plants will soon return with a burst of fresh, colorful blooms.