Quick Reference

Type of Harvest: Continuous harvest

Transplant/Direct Sow: Direct sow or transplant

When to Plant: Start seeds indoors 4 weeks before the average last frost date for spring. Petunias do not tolerate temperatures below 40°F. Direct sow seeds when the nighttime temperature are above 55°F.

Days to Germinate: 5-15 days

Days to Maturity: 70 days

Planting Depth: 1/4” deep

Germination Temp: 55°F

Seed Spacing: Plant 1” apart. Thin to 6-12” apart.

Row Spacing: 1.5" apart

Light: Full sun

Soil pH: 6.0-7.0 pH

Water: 1- 2” of water per week - mpre for hanging baskets.

Soil Temperature: Minimum 55°F. These are warm weather loving plants.

Fertilizer: 10-10-10 N-P-K ratio

Rotation: There is no need to rotate petunias so long as you amend the soil with compost or high-nutrient plant food.


Harvest Type

Petunias continue to bloom all season long. They will bloom until the first frost.

Transplant / Direct Sow

In the spring, start seeds indoors about 4 weeks before the average last frost date. Direct so petunia seeds when the soil temperatures are 55°F or warmer. Petunias do not tolerate frost.


Full Sun

When to Plant:

Transplant or direct sow seeds when the soil temperature is 55°F.

Days to germinate

It takes most Petunias 5-15 days to sprout.

Days to maturity

It takes about 70 days for petunias to mature.

Planting Depth

Plant seeds 1/4" deep.

Germination Temperature Range

Germination is best when the soil is 55°F.

Spacing Between Plants

Plant seeds 1" apart and thin to 6-12". Petunia are draping plants and will grow wider with more space.

TIP: If planting in a hanging basket, use moisture retaining soil that will allow the basket to hold water throughout the hotter parts of the day.

Companion Plants

Asters, Lantana, Snapdragons, and Daisy' all make excellent companion plants for Petunias.

Growing conditions

Petunias like warm weather. Start with good, well-draining soil—water with 1-2" of water per week, keeping the ground evenly moist. If planting in hanging baskets' water daily. Plant in full sun. For faster bloom times, start seeds indoors about 4 weeks before the average last frost date.

Tip: Water retention gel can be helpful to keep hanging basket arrangements looking their best for a much longer time.


There is no need to rotate petunias if you amend the soil in containers each spring.

Anticipated yields

Plan your garden yield at 4-10 Petunia for a 3-foot bed. Expect continuous blooms throughout the summer and warmer parts of fall. Petunia are amazing at attracting bumblebees to your garden.