Geraniums bloom throughout the summer months, adding color to beds and containers. As a tender perennial, geraniums are often grown as annuals since they don’t tolerate winter frosts. Starting new plants from seed in later winter allows you to replace your favorite variety of geraniums without the purchasing bedding plants. Geraniums take approximately 14 weeks from seed to flower, so start the plants indoors at least three months before the last expected spring frost in your area.
Things You’ll Need
- Potting soil
- Metal file
- Plastic bag
- Set seed-starting flat filled with a soil-less potting mixture inside a second tray filled with water. Soak the flat until the soil surface becomes moist, then dump the excess water out of the tray.
- Scuff one side of each geranium seed with a metal file or a medium grit sandpaper until the outer seed coating is rubbed away. Scuffing the seed, called scarifying, allows water to reach the interior of the hard geranium seed and speeds germination.
- Sow seeds on the soil surface, spacing them ¼ inch apart in rows. Space the rows 2 inches apart. Cover the seeds with 1/8 inch of moistened potting mix after sowing.
- Slide the flat into a plastic bag and seal the bag closed. Set the flat in a 70 to 75 degrees Fahrenheit room to germinate.
- Remove the plastic bag once sprouts appear, usually within two weeks of sowing the geranium seeds. Move the flat to a warm, sunny location and water the soil when the surface begins to dry.
Tips & Warnings
Geranium seeds may take longer to germinate if the soil temperature is below 70 F.
Transplant the healthiest seedlings to individual pots until the weather permits you to plant them outside.