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How to Propagate Petunias

Petunias are prolific bloomers that provide a blanket of color from early summer to frost. Often used in containers, window boxes and hanging baskets, petunias come in shades of white, pink, purple and red and provide a delicate fragrance. New varieties of wave petunias cascade freely from hanging baskets, reaching lengths of several feet. Although some petunias are self-cleaning and do not require regular deadheading, many benefit from removal of spent blooms but are otherwise carefree plants that grow rapidly. Propagating petunias is easy, but must be done several weeks before planting time.

Things You'll Need

  • Seed starter
  • Flats/trays
  • Petunia seeds
  • Clear plastic
  • Mister
  • Plant pots
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Instructions

    • 1

      Start petunia seeds indoors eight to 12 weeks before the last expected frost. Sow seed on the surface of seed starter in trays or cells. Do not cover the seeds.

    • 2

      Water to thoroughly moisten the soil and cover with clear plastic to increase the humidity level.

    • 3

      Place in an area that receives direct or bright filtered light. Petunia seeds require light to germinate.

    • 4

      Mist daily to keep the soil moist and do not allow it to dry out. Germination will occur in seven to 21 days depending on the soil temperature and the species.

    • 5

      Remove plastic once seedlings emerge and place in sunny location. Keep soil moist.

    • 6

      Transplant to individual pots when seedlings have their second set of leaves--approximately two to three weeks.

    • 7

      Plant seedlings outdoors once the danger of frost has passed and temperatures remain above 50 degrees.