Most of us know petunias as the undisputed royalty of the balcony box. These stunning summer bloomers originally hail from the warm climates of South America, which tells you a lot about what they need to thrive. If you want those vibrant colors to really pop, picking the right spot in your garden is half the battle.
Petunias Are Total Sun-Worshippers
While petunias can handle a bit of partial shade, they really need a full-sun location to reach their full blooming potential during the summer months.
Beyond just soaking up the rays, here’s what your petunias need at their home base:
- Plenty of water: Keep in mind that full sun means the soil dries out fast!
- Well-draining soil: This is key for helping the roots establish themselves and stay healthy.
- A little TLC: Deadheading (pinching off wilted blooms) encourages the plant to keep pumping out new flowers.
- Protection: Try to find a spot that’s shielded from heavy wind gusts and pouring rain.
On balconies, most gardeners go for trailing varieties that spill beautifully over the edges. Upright varieties, on the other hand, look great in patio troughs or garden beds. Just a heads-up: petunias appreciate a bit of a “roof” over their heads, like a porch overhang. A particularly rainy summer can really beat them down and lead to disease if they aren’t protected.
Keep Them Safe from Frost
Since they love the heat, petunias are definitely not fans of the cold. Keep a close eye on the weather forecast! Even after a sunny day, clear nights can bring unexpected frost. If the temperature is set to dip, move your pots and hanging baskets indoors where it’s warm.
If you’ve overwintered your plants, don’t just rush them outside the moment it hits 60 degrees. Give them about two weeks to “harden off.” This adjustment period helps them get used to the outdoor air, wind, and direct sun. This little bit of patience goes a long way in ensuring your petunias stay healthy and grow vigorously.
Starting Petunias Indoors
An unheated greenhouse or a sunny sunroom is the perfect place to start your petunias from seed for the upcoming season.
Here’s how to do it:
- Place your seed tray in a bright, warm spot.
- Cover the tray with plastic wrap or a clear lid to create a mini-greenhouse effect.
- Lift the cover daily to let in some fresh air.
- Keep the soil consistently moist but not soggy.
- Once the seedlings have two pairs of leaves, you can “prick them out” and move them into individual 4-inch pots.
- By mid-May, once the danger of frost has passed, your young plants are ready to move out to the balcony or garden.
