Mention petunias among a group of passionate gardeners and you often get sneers. After all, they’re so… common! Even non-gardeners grow petunias. Those with greener thumbs usually aspire to more exotic flowers. But there’s a reason petunias are so popular among the casual gardening crowd. In fact, there are a number of reasons.
There are four general types of petunias: grandiflora, multiflora, milliflora, and spreading. Look at the label to see which kind you are buying.
Grandifloras have the largest flowers—three to four inches across—and tend to spread a bit. Multifloras produce more blossoms on more compact plants, but each flower is only one to two inches in diameter. Millifloras take this to an extreme, with even more, one-inch flowers, and an upright growth habit. Spreading petunias also have smaller blossoms, and can cover a large area in a single season.
Select the ones that best suit your intended purpose. Opt for the compact multifloras and millifloras to place in front of perennial borders, in flower beds, and in pots. Choose grandifloras and spreading petunias for window boxes, hanging containers, and to cascade over walls. I add petunias to my patio containers every summer. They are polite about sharing the limited root space in my pots, and they fill in any gaps with a profusion of big, showy blooms that continue all summer.
Since petunias come in nearly every color, even black, you can use your imagination to match or contrast them with other flowers. Some have single flowers with five petals while others are double, or even fuller.
Petunias are very easy to grow. While they prefer loam with an ideal 5% organic matter, they’re quite forgiving of less-than-perfect soil and fertility. In fact, unless your soil is absolutely horrid, you probably don’t need to do more than mulch.
To enjoy the most flowers, situate your petunias in full sun. But if partial shade is all that’s available, they’ll still manage to produce some flowers. You may have to pinch the plants back a tad to keep them from getting too leggy (just remove the growing tip), but they’ll quickly recover and reward you with more branches and more flowers.
While petunias do best with regular watering, they are somewhat drought tolerant. They may wilt if you delay a watering, but they usually bounce back if you don’t wait too long. Again, mulch helps maintain even moisture levels. And while petunias are considered tender annuals, I find that they frequently survive a very light frost and temperatures in the low 30s. Just don’t expect them to be alive after a hard freeze!
If the idea of winter-killed petunias dismays you, you can bring them in to continue life as a houseplant. Put them in a sunny window and you’ll get several more months of bloom. Eventually the stems get too long and the plants seem to run out of energy. At that point, you can simply start over. Cut off several inches at the growing end of the plant and root the stems in water.
You can buy petunia seedlings pretty much anywhere plants are sold, from garden centers to big box home improvement stores to the local supermarket. If you want to start from seed, which will give you a greater selection of varieties, sow them ix to ten weeks before the last expected frost in your area—perhaps now!
Petunias are a versatile annual that can be used in so many ways. Besides, I think they’re pretty. So what if they’re common?