Petunias come in a number of different kinds and combinations. They are one of the best flowers to bright up your garden or area near the house. They are really easy to grow and can be planted in hanging baskets, containers or in the ground. They’ve become popular in the mid 19th century when the Europeans brought them from USA. Petunias grow naturally in the US zones 9 to 11 and they can’t handle freeze at all. If these flowers grow outdoors, they die every winter but you can easily grow them again next season.

Growing petunias from seedlings
Before planting petunias, you need to prepare soil and choose the location.
Try to plant them in the sunny location with 6-8 hours of sun every day. Spread some organic manner (two to three inches thick) and mix it with the soil.  Soil also must drain decently.
Plant petunias only after the last frost, otherwise they may die.
If you bought petunias in the peat pots, then just remove them out of there and gently tease their roots apart with your fingers.
Place them in the soil, cover the root ball and gently firm the soil down.
You have to keep the soil moist until you see a new growth. That shows you the petunias have developed a strong root system.

Growing petunias from seeds
I recommend to start growing petunias indoors. Although it takes about 10-12 weeks before petunias are big enough to plant out, but you can save some money, because garden seeds cost less than petunias seedlings and you can grow more plants.
Prepare clean, damp potting soil or milled sphagnum moss. Sprinkle the seeds on top if it and press them in gently with your fingers before watering.
Cover the container with plastic bag or any other plastic and store it in a bright, warm (70 to 85 degrees F) place. Do not place them under direct sunlight.
Seeds begin to sprout 7-10 days after planting. You’ll have to remove plastic and relocate the container to a cooler place with about 65F during the day and 55-65F during the night.
Plant seedling into individual peat moss or paper pots (use pot maker to make them)  when they have 3 true leaves.
After the last frost, you can plant them outdoors.

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(c)Garden Seeds

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Help the world! Use paper pot maker!
(c)Garden Seeds