Can Petunias Survive Outside?

Petunias thrive in full sun and grow well in containers, so they make ideal flowers for small spaces as well as landscaped flowerbeds on large properties. Most modern-day petunias are a hybrid of South American origin and are well-known for a showy display all season. Choose the best placement and soil types in your garden or balcony to ensure its success.

Ideal Placement

• Petunias can be sown from seed indoors a few weeks before planting season gets underway, or you can purchase seedlings or full-grown plants at a nursery to place in your container or garden. Pick a location that gets plenty of sunshine before transplanting, although petunias can do well in partial shade. Don’t place outdoors until after the danger of a late frost has come and gone (alternatively, you can test the soil temperature — planting is safe after it reaches at least 60 degrees Fahrenheit).

Soil

• Petunias do best in well-draining soil, so if you are not planting them in a container with potting soil, you must make sure the spot in your garden that you pick drains well. To determine this, you can dig a hole in the area 1 inch deep and 2 inches wide and fill it with water. If it drains away in around 30 minutes, your soil is in good shape for petunias. If it takes longer, it may be too compact or has excessive clay.

Maintenance

• Deadheading, or pinching off the withered flowers, is a great way to decrease green growth and encourage more blooms. Water abundantly after transplanting and daily, but only when the soil around the plant becomes dry. Excessive watering can cause damage to the plant or it can cause it to become spindly. Add mulch around the base of your plant to control weed growth as well as lessening the need for frequent watering.

Known Issues

• Petunias generally are unaffected by pests although the budworm caterpillar does love to eat the buds and leaves. Maintaining the proper soil moisture can prevent many known petunia problems as can adding a few nutrients if the leaves turn yellow. Petunias, while thriving well, do not tolerate below-freezing temperatures, so expect their season to end once the first cold spell rolls through your area. As annual plants, they will not regrow the following year.