7-Step Easy Guide for Growing Petunias From Seed
- Author: Saiqa Najeeb
- Last Updated On: July 7, 2023
Want to add colors to your garden space? Start growing Petunias from seed. These captivating flowers can turn any space into a beautiful wonderland.
But you have no idea about how to get started. We’ve got you covered. We’ll help you to jumpstart your fruitful journey with Petunias. You’re going to be equipped with all the nitty-gritty of growing Petunias from seed to enchanting blooms.
Ready to explore the world of Petunias? Let’s get growing!
About Petunia
Garden Petunia is an annual in the nightshade family that blooms continuously from summer until frost and is one of the most popular bedding plants. Although many people purchase plants from nearby nurseries in six-packs, seeds can be placed under glass from January to March since they need a temperature of 72 to 75 degrees to germinate. Before transplanting newly purchased plants, pinch them back to keep them bushy.
Growing conditions
Here are the optimal conditions for growing petunias from seed:
Light:
- 6 or more hours of direct sunlight a day (Full sun),
- Direct sunlight only part of the day, 2-6 hours (Partial Shade)
Soil Drainage: Good Drainage, Moist
Space Required To Plant: 12 inches-3 feet
USDA Zone: 10a, 11a, 10b, 11bs
Choosing Petunias
For growing petunias from seed, you can choose from the following:
Grandiflora petunias: These are the most common species that produce huge flowers three to four inches or more in diameter. It could be singles or ruffled doubles. Some have a pendulous, cascading habit that makes them ideal for hanging baskets and window boxes, but the majority are upright plants that grow into big mounds of blossoms that are 12 to 15 inches tall over the summer.
Multiflora petunias: They are frequently more compact. Their flowers are smaller than those of grandifloras, but they make up for it by having a greater number of blossoms open at any given moment. Like other grandiflora variations, come in single or double forms, with the vast majority being singles. They are typically massed together to create large splashes of color in the garden.
Multiflora petunias are compact, little plants that produce an abundance of lovely, small flowers ranging in diameter from one inch to an inch and a half. They make excellent edging plants and look great when blended with other flowering annuals in containers where they can be seen up close.
Groundcover or “spreading” petunias: Groundcover or “spreading” petunias: They are only about six inches tall, but they spread so quickly that if watered and fertilised frequently, they can cover a considerable area in one growing season.
As a result, they are great for scaling down a hillside garden or planting on top of a retaining wall. They also look great in hanging baskets and window boxes, where they can trail two to three feet or more throughout the summer. When grown in full sun, the blossoms cover the leaves to the point where you can’t see them. A frequent type of spreading petunia is the “wave” petunia.
Preparing Soil for Growing Petunias from seed
Petunias require at least 5 or 6 hours of direct sunlight per day, and they thrive in full sun all day. The more shadow they get, the fewer flowers they produce. Impatiens are a better choice for shady areas since they bloom earlier.
While soil does not need to be overly rich to grow nice petunias, it must drain well. It is always beneficial to condition garden soil with organic matter such as peat moss, compost, or manure. Apply the organic material in a 2 to 3-inch thick layer. Using a rototiller or garden fork, work it into the soil to a depth of 8 to 10 inches. It aids in the opening up of heavy clay soil, which increases drainage, but it can also increase the ability of light, sandy soil to hold water.
Starting Seeds Indoors
When to sow seeds?
You can sow petunia seeds indoors for approximately 10 weeks before you plan to put them outside. (Petunias should be planted outside once the risk of frost has passed.
Containers and Media
A good germination medium is a commercially manufactured medium, such as Jiffy Mix. Containers for seedlings should be clean and have holes for drainage in the bottom. Containers should be rinsed in soapy water and disinfected with a solution of one part chlorine bleach to nine parts water.
Fill the container to within 1 inch of the top, then lightly firm. Next, slightly submerge the container in water to wet the medium. Remove the container when the surface becomes moist, leave it to drain for 15 to 20 minutes, and then sow the seeds. A fine spray from a sprinkler can also be used to wet the medium.
Sowing the Seeds
Petunia seeds are quite tiny. (An ounce contains around 250,000 to 300,000 seeds.) Sowing the delicate petunia seeds is challenging for many amateur gardeners. Pelletized petunia seeds, on the other hand, are frequently available. Pelleted seeds are seeds that have been coated with a substance that makes them bigger and easier to handle.
Carefully plant the seeds on the soil’s surface, then use a pencil or a small piece of wood to press them into the germination media. Because petunia seeds require sunshine to germinate, they should not be buried or topped with additional material. After sowing, use a sprinkler or partially submerge the container in water to soak up the medium.
Germination and Care
For optimal seed germination, uniform medium temperatures and moisture are essential. Place the container in an area that is warm and sunny (75 to 80 °F). Place a sheet of clear plastic food wrap or a plastic dome over the container to ensure constant moisture levels. Set the covered container away from direct sunlight. High temperatures caused by direct sunshine can hinder or prevent germination. Petunia seeds are expected to sprout in 7 to 10 days.
Planting petunia
Before planting petunias in the garden, wait until the soil temperature reaches 60 degrees Fahrenheit and the frost risk has gone. Grandifloras and multifloras should be planted about 12 inches apart in full sun, or several inches closer together in a shadier site. Milliflora petunias can be planted as close together as 4 to 6 inches apart. Petunias with spreading ground cover should be planted at least 1 1/2 feet apart.
Petunias must be planted much closer together in containers to seem full and appealing from the start. If the weather is hot or windy with few clouds at the time of transplanting, try to offer some shade from the midday sun for the first several days. When grandifloras or multifloras reach about six inches in height, pinch them back to encourage
Caring for Petunia
Fertilizing: When planting in the garden, work a balanced fertilizer into the soil at a rate of 2 pounds per 100 square feet, such as 8-8-8, 10-10-10, or 12-12-12. Later, in early to mid-July, start using liquid fertilizer every three weeks. “Spreading” varieties require weekly fertilising. Incorporate timed-release fertiliser into the soil while growing in window boxes or other pots. Later, in early to mid-July, start fertilizing every two weeks using a liquid fertilizer designed specifically for flowering plants.
Have an accurate soil test performed for a fertilizer prescription tailored to your individual garden requirements. Contact your county extension office or the Soil Testing Lab for more information.
Watering: Petunias can withstand high temperatures and have low water requirements. Except for “spreading” varieties, which require frequent watering, thorough watering once a week should suffice in all save the most extreme weather.
Every time you water, leave the sprinklers on long enough to wet the soil to a depth of 6 to 8 inches.Hanging baskets and other containers, depending on their size and the volume of soil they contain, require more frequent watering, possibly as frequently as daily.
Deadheading: When possible, remove faded blooms, including the area beneath each blossom where seeds may form. This technique, known as “deadheading,” promotes blooming by reducing seed production. Although deadheading masses of petunias in the garden may not be practicable, it is essential for flowering annuals in pots. Deadheading not only prolongs blooming but also keeps plants looking fresh, healthy, and well-kept.
Finally, if you have an excess of petunias flowering in the garden, it’s not a bad idea to clip a piece of stem here and there to use in bouquets and floral arrangements. Simply remove any leaves that will be submerged in the vase, where they will decay quickly.
That's a wrap
Growing petunias from seed is a delightful experience, that everyone should enjoy. The vibrant colors of petunias not only add a touch of beauty to your space but also has a profound effect on your mental well-being.
It’s time to put your garden space to the best use. Follow all the guidelines and tricks given in this guide to kickstart your journey. Don’t forget to experiment with different varieties and colors.
Sow the seeds today and get ready to enjoy the sweet fragrance infused in your space.
