Unleash your green thumb and enjoy beautiful blooms all season with this step by step guide on how to grow geraniums from seed!
Geraniums, also known as Pelargonium, are a beautiful flowering plant with over 200 species and hybrids. They are beloved for their attractive foliage and vibrant blooms, making them a favorite for garden beds, containers, and hanging baskets.
Geraniums are appreciated for their ease of care, long blooming season, and wide range of colors and forms. But at a price of $8-10 a plant, it can get expensive to fill a large area or pot!
Luckily, it's really easy to grow geraniums from seed. For the price of just a single plant, you can sprout dozens of them yourself. Here's how!
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Types of Geraniums
There are four different types of geraniums, each with their own features. Some have huge clusters of flowers on long stems, while others trail and drape. You're sure to find a favorite in this list!
Zonal geraniums (Pelargonium hortorum) are the most common variety. They have rounded, slightly lobed leaves with a distinct dark band or "zone" and produce large clusters of flowers in various colors, including red, pink, white, and purple.
This is the type of geranium I'm growing from seed this year. Specifically, I'm growing the Maverick Star geranium, a gorgeous pink and white bicolor.
Ivy geraniums (Pelargonium peltatum) have a trailing habit and glossy, ivy-like leaves. Their flowers come in shades of red, pink, lavender, and white, making them a popular choice for hanging baskets and window boxes.
Regal geraniums (Pelargonium domesticum), also known as Martha Washington or royal geraniums, boast large, showy flowers with intricate patterns and colors. They have a more compact growth habit and bloom primarily in spring and early summer.
Scented geraniums (Pelargonium spp.) are valued for their fragrant leaves that release various scents, such as rose, lemon, mint, and even chocolate. While their flowers are usually smaller, they make excellent additions to gardens and containers for their aromatic foliage.
Growing Geraniums from Seed
While it's pretty easy to grow geraniums from seed, there are a few things to keep in mind for successful germination.
Start your geranium seeds early (I sowed mine in mid-February for growing zone 8b). It can take anywhere between 13 and 15 weeks for these geraniums to flower, so they need a decent head start so you can enjoy the blooms all season long.
Use clean, sanitized seed trays or pots with drainage holes. Fill them with pre-moistened seed-starting mix, removing any air pockets at the bottom.
Press the seeds gently into the surface of the soil without covering them, as they need light to germinate. I'm sowing two seeds per cell, then potting them up into separate containers once they've put on some size.
Mist the surface and place a humidity dome or plastic wrap over the top of the tray to keep moisture levels high.
Maintain a consistent temperature of 70-75°F (21-24°C) for germination. My basement is colder than that, so I'll use a heat mat to keep them warm. Keep the soil evenly moist but avoid overwatering, as this can lead to rot or fungal issues such as dampening off.
Place the containers in a bright, sunny window or under grow lights. Geranium seeds typically germinate within 7-14 days, although my seed packet said it could take 14-21 days. Mine took about 10 days to emerge.
Potting Up Geranium Seedlings
Once your seedlings develop their first set of true leaves (the second set of leaves that resemble mature geranium foliage), they are ready for transplanting into a larger container. Mine were ready to get potted up after just two weeks!
I save all my four inch pots and trays from the nursery, because they're perfect for potting up seedlings like these. Just make sure to clean them thoroughly so you don't transfer any disease to your little seedlings!
You can use regular potting mix at this point. It will provide your seedlings with the nutrients they need to grow large enough to transplant outside. They'll be in these pots until the weather warms up to a consistent 65-70 degrees during the day and 45-50 degrees at night. Once it gets to that point, I'll share all my tips for transplanting geraniums out into the garden!