Geraniums are a group of flowering bedding plants that have withstood the test of time and remain one of the more popular flowering plants, according to North Carolina State University. Their popularity can be attributed to their vigor, choice of colors and growing habits. The Geranium x "Johnson's Blue" is also known as "Johnson's Blue" cranebill. This variety of geranium is both hardy and tolerant of a wide variety of soils, although it requires regular watering throughout its growing season. Growing "Johnson's Blue" geraniums from seed will provide you with many of these prolific blooming plants for your flower garden.
Pour 1 to 2 tbsp. of a liquid soap into a basin or sink that has been filled with hot water. Set each of the pots into the soapy solution. Use a brush to scrub each pot.
Pour 1 cup of bleach into a bucket or basin that contains 9 cups of water. Soak the pots in this solution for about 10 to 15 minutes to further sterilize the pots. This is necessary to help prevent any fungi from killing the seedlings.
Scoop a sterilized seed starting mix into the plastic pots until they are each filled to about 1/2 to 1 inch from the top. Pack the mixture firmly down into each of the pots to remove air pockets. You can use a metal spoon or a fork to accomplish this.
Nick or scratch off a section of the seed coat on each of the Geranium x "Johnson's Blue" seeds. Use a nail file or a hobby knife to do this.
Plant two Geranium x "Johnson's Blue" seeds into each of the plastic pots. Sprinkle a light layer, about 1/8 inch, of the seed starting compost over the seeds. Mist each of the pots with a fine mist of water until the mixture becomes well-moistened.
Cover the pots with a layer of plastic wrap. Transfer the pots to a location that will provide a lot of light, ideally between eight and 10 hours a day. Avoid any location in direct sunlight that will create too much heat and scorch the seeds. A good temperature during the germination period is between 70 and 75 degrees F. Watch for the seeds to begin sprouting in about seven to 10 days at the above conditions.
Remove the layer of plastic wrap from the pots once the seeds begin to sprout. Place the pots 4 to 6 inches away from a fluorescent light for about eight to 10 hours a day to make sure the seedlings are provided enough light so they will not grow spindly.
Thin down the Geranium x "Johnson's Blue" seedlings to one plant per pot once they have two pairs of leaves. To do this use a pair of scissors and snip off at the soil line the less hardy seedling in each pot. Begin fertilizing the seedlings once they are about 2 to 3 weeks old. Use a liquid fertilizer and dilute it to half strength.
Transplant each of the "Johnson's Blue" geranium seedlings into a sun-filled to partially shaded location in your garden when they are about 3 to 4 inches tall. You can also plant them in tubs or barrels.