Growing Geraniums in December: Tips and Advice for Sowing and Caring for Geraniums

Geraniums are a popular and versatile plant known for their vibrant blooms and ability to thrive in a wide range of conditions. While many gardeners think of geraniums as summer plants, December is an excellent time to get a head start on the growing season by sowing geranium seeds indoors. By starting them early in the winter, you’ll ensure strong, healthy plants that will bloom beautifully by the time summer rolls around.

In this guide, we’ll cover the process of sowing geranium seeds in December, tips for indoor growing, and advice on how to care for your geraniums throughout the winter to ensure they thrive in the spring and summer.

Why Sow Geranium Seeds in December?

Sowing geraniums in December gives you a head start on the growing season. Geraniums can take several weeks to germinate and several months to grow strong enough to transplant outdoors. By starting them in December, you’ll have healthy, mature plants ready to bloom as soon as the weather warms up.

Starting geraniums indoors also allows you to control the environment, ensuring they get the light, warmth, and care they need to grow strong and vibrant.

Benefits of Sowing Geraniums in December:

1. Early Bloom: Sowing geranium seeds in December means you’ll have mature, blooming plants ready for the garden by late spring or early summer.
2. Control Over Growing Conditions: Growing geraniums indoors allows you to control light, temperature, and humidity, giving your plants the best possible start.
3. Hardy Plants: Geraniums started in winter develop strong root systems, making them more resilient and ready for transplanting outdoors.
4. Extended Blooming Season: By starting early, you’ll enjoy a longer blooming period, with flowers lasting well into the summer and early fall.

Choosing Geranium Varieties to Grow in December

There are many different types of geraniums to choose from, each with its own unique color, size, and growth habit. When selecting geraniums to sow in December, it’s important to consider where you’ll be planting them and the type of bloom you’d like to achieve.

Popular Geranium Varieties:

• Zonal Geraniums: Known for their bold, vibrant flowers and large, round leaves, zonal geraniums are a popular choice for garden beds, containers, and hanging baskets. They come in a variety of colors, including red, pink, white, and purple.
• Ivy-Leaf Geraniums: With trailing stems and delicate flowers, ivy-leaf geraniums are perfect for hanging baskets and window boxes. They have a cascading growth habit, making them ideal for adding vertical interest.
• Regal Geraniums: Also known as Martha Washington geraniums, these plants produce large, showy blooms with ruffled petals. They are perfect for adding a dramatic splash of color to containers or garden borders.
• Scented Geraniums: Scented geraniums are prized for their fragrant leaves, which can smell like rose, lemon, mint, or even chocolate, depending on the variety. While their flowers are smaller than other geraniums, their delightful scent makes them a favorite for containers and herb gardens.

When choosing a variety, consider the growing conditions in your garden or home, and select a geranium that will complement your space and bloom in the colors and forms you love.

How to Sow Geranium Seeds in December

Geranium seeds are easy to sow indoors, but they do require time to germinate and grow into strong plants. By sowing them in December, you’ll give them plenty of time to develop before transplanting them outdoors in the spring.

Step-by-Step Guide to Sowing Geranium Seeds:

1. Choose the Right Containers: Start by choosing seed trays or small pots with good drainage. You can use seed-starting trays, small peat pots, or recycled containers with holes for drainage.
2. Fill with Seed Compost: Fill your containers with a light, well-draining seed-starting mix. You can use a pre-made seed compost or create your own by mixing equal parts compost, perlite, and vermiculite.
3. Sow the Seeds: Scatter the geranium seeds on the surface of the compost. Geranium seeds are tiny, so sow them evenly, spacing them about 2-3cm (1 inch) apart. Lightly press the seeds into the compost, but do not bury them too deep, as they need light to germinate.
4. Cover and Water: Lightly mist the surface of the compost with water to keep it moist, but avoid overwatering. Cover the trays with a clear plastic lid or place them inside a propagator to maintain humidity.
5. Provide Warmth: Geranium seeds need a warm environment to germinate. Place the trays in a warm spot, such as on a sunny windowsill, or use a seed-heating mat to maintain a temperature of around 21-24°C (70-75°F).
6. Light: Geranium seeds need plenty of light to germinate. Place the trays in a bright location where they will receive indirect sunlight. If natural light is insufficient, consider using grow lights to ensure the seeds receive enough light.

Germination Timeline:

Geranium seeds typically take between 7 to 21 days to germinate, depending on the variety and growing conditions. Keep the compost consistently moist, but avoid waterlogging, as this can cause the seeds to rot.

Caring for Geranium Seedlings in Winter

Once your geranium seeds have germinated, they will start to grow into small seedlings. At this stage, they require careful attention to ensure they grow strong and healthy.

Light and Temperature

As the seedlings grow, they need plenty of light to develop strong stems and leaves. Place them in a location that gets 6-8 hours of sunlight per day, or use grow lights to supplement natural light if needed. Ensure the temperature remains between 18-21°C (65-70°F) to promote steady growth.

Watering

Keep the compost slightly moist but not waterlogged. Overwatering can lead to damping-off disease, a fungal condition that can kill young seedlings. Water gently from the base or use a misting spray to avoid disturbing the delicate seedlings.

Thinning and Transplanting

Once your seedlings have developed their first true leaves (the second set of leaves), it’s time to thin them out. If you’ve sown multiple seeds in one container, thin them by gently pulling out the weaker seedlings, leaving the strongest ones to continue growing.

When the seedlings have grown large enough to handle, transplant them into individual pots filled with a high-quality potting mix. This will give the plants more room to develop strong roots.

Fertilizing

Once the seedlings are a few weeks old and have developed strong roots, start feeding them with a balanced, water-soluble fertilizer every two weeks to encourage healthy growth.

Preparing Geraniums for Transplanting Outdoors

By the time spring arrives, your geranium seedlings should be well-established and ready to be transplanted into the garden or containers. However, before you move them outside, it’s important to harden them off to help them adjust to the outdoor conditions.

Hardening Off

Hardening off is the process of gradually acclimating your indoor-grown geraniums to the outdoor environment. About two weeks before your last expected frost, start placing your geraniums outside for a few hours each day, gradually increasing the amount of time they spend outdoors. Be sure to bring them inside at night or if the temperature drops significantly.

Once the danger of frost has passed and the weather has warmed up, you can transplant your geraniums into the garden or containers.

Transplanting Geraniums Outdoors

1. Prepare the Soil: Geraniums thrive in well-drained soil that is rich in organic matter. Choose a sunny location, as geraniums need at least 6 hours of sunlight per day to bloom well.
2. Spacing: When transplanting geraniums into the garden, space the plants about 30cm (12 inches) apart to allow for good air circulation and healthy growth.
3. Watering: Water the plants thoroughly after transplanting to help them settle into their new environment. Continue to water regularly, but avoid overwatering, as geraniums prefer slightly dry conditions between waterings.

Caring for Geraniums in the Garden

Once your geraniums are transplanted outdoors, they will require regular care to ensure a long blooming season.

Watering

Water your geraniums when the top inch of soil feels dry, being careful not to overwater. Geraniums are relatively drought-tolerant but will bloom best with consistent moisture.

Fertilizing

Feed your geraniums every two to four weeks with a balanced fertilizer to encourage strong growth and abundant blooms. Be careful not to over-fertilize, as this can lead to excessive foliage growth at the expense of flowers.

Deadheading

To keep your geraniums looking their best and encourage continuous blooming, deadhead regularly by removing spent flowers. This will help direct the plant’s energy into producing new blooms.

Pests and Diseases

Geraniums are generally low-maintenance, but they can occasionally suffer from pests like aphids and whiteflies. Keep an eye out for any signs of infestation and treat with insecticidal soap or neem oil if necessary.

Conclusion

Sowing geraniums in December is an excellent way to get a head start on the growing season and ensure your garden is filled with vibrant blooms by the time summer arrives. By following the steps outlined in

this guide, you can successfully start your geranium seeds indoors, care for them through the winter, and enjoy a long, colorful blooming season.

With proper care and attention, your geraniums will thrive, providing you with beautiful flowers that will enhance your garden, patio, or windowsill for many months to come.

Find out more things you can grow in December here