Geranium in Zone 8B — Southeast

Geraniums bring a classic charm to any Southern garden. Their vibrant colors and ease of care make them a rewarding choice. They are especially good in containers, window boxes, and even garden beds. Plus, their scent is a pleasant bonus.

The Southeast's long summer and reliable rainfall are great for Geraniums, but we also have to deal with humidity and fungal diseases. Starting your plants at the right time, and giving them good airflow, will help you enjoy their blooms all season long. Our 255-day growing season gives you plenty of time to enjoy them.

Starting Geraniums from seed indoors is an option, but be warned: they can be slow to get going. If you want to try it, sow seeds indoors from late December through mid January, about 12 weeks before you plan to transplant them outside.

Use seed trays with a good seed-starting mix. Keep them consistently warm (around 70-75°F) and provide plenty of light – a grow light works best. Bottom watering is a good way to keep the soil moist without damping off. The moderate spring here in the Southeast means you'll have time to get them established indoors.

The easiest way to get a head start is to buy Geranium starts from your local garden center. However, if you've started your own, transplant them outdoors from late March through late April. Before transplanting, harden them off by gradually exposing them to outdoor conditions for about a week.

Space plants about 10-12 inches apart in well-draining soil. Keep an eye on the weather – we can still get some cool snaps in late March and early April, so be ready to cover them if needed. Remember, Geraniums are tender and don't like frost.

Watering Geraniums correctly is vital in our hot, humid climate. They need moderate watering, but overwatering is a killer, leading to stem rot. In the Southeast, it's best to let the soil dry out slightly between waterings.

During our hot summers, you will probably need to water every 2-3 days. Stick your finger about 2 inches deep into the soil. If it feels dry, it's time to water. Aim for about 1 inch of water per week, including rainfall. Water at the base of the plants to avoid wetting the foliage, which can encourage fungal diseases in our humid air.

Signs of underwatering include wilting leaves and dry, crispy edges. Overwatering can cause yellowing leaves and mushy stems. A good layer of pine straw mulch will help retain moisture and keep the soil cooler during our long summer.

Deadheading is essential for keeping your Geraniums blooming. Throughout the season, pinch off spent flower clusters as soon as they start to fade. This encourages the plant to put energy into producing new blooms instead of seeds.

If your plants get leggy, pinch back the stems to encourage bushier growth. Towards the end of the season, as we approach the first frost in mid- November, you can give them a final trim to tidy them up before bringing them indoors (if you plan to overwinter them) or letting them go.

Geraniums are grown for their beautiful blooms, not for eating. Expect your plants to start flowering from early June through late July, about 70 days after transplanting.

Enjoy the flowers in your garden all season long. Regularly remove any faded blooms to keep the plants looking neat and encourage continuous flowering. As the weather cools in the fall, you can take cuttings to propagate new plants or bring your Geraniums indoors to overwinter. Just be sure to give them plenty of light if you bring them inside.

Geraniums can face a few problems in the Southeast's climate. Here are three common issues and how to deal with them:

Botrytis Blight

• What it looks like: Gray mold on leaves, stems, and flowers.
• What causes it: High humidity and poor air circulation create the perfect environment for this fungal disease. It's a common problem during our wet-summer season.
• How to fix/prevent it: Improve air circulation by spacing plants properly and pruning out crowded growth. Remove and destroy any infected plant parts. Use a fungicide if the problem is severe, but prevention is key.

Geranium Budworm

• What it looks like: Holes in buds and flowers, chewed leaves, and small green caterpillars.
• What causes it: These caterpillars feed on Geraniums, causing significant damage.
• How to fix/prevent it: Handpick caterpillars when you see them. Use Bacillus thuringiensis (Bt) spray, an organic insecticide, to control infestations.

Edema

• What it looks like: Small, blister-like bumps on the undersides of leaves.
• What causes it: Overwatering and poor drainage, especially during cool, cloudy weather. This is common in our clay soil if drainage isn't improved.
• How to fix/prevent it: Improve drainage by amending the soil with compost. Water only when the top inch or two of soil is dry. Provide adequate air circulation.

Southeast Specific Challenges: Our hot, humid summers and wet-summer rainfall create a perfect environment for fungal diseases like botrytis blight. The humidity also makes Geraniums more susceptible to edema if not watered carefully. Be vigilant about monitoring your plants and taking preventative measures to keep them healthy.

Geraniums make good companions for several plants in the Southeast garden. They are often planted near tomatoes and peppers to help repel certain pests, possibly tomato hornworms and aphids. The strong scent of Geraniums can also deter cabbage moths from brassicas like broccoli and cabbage.

They also do well planted near corn. Some gardeners swear by planting them near roses to deter Japanese beetles, which can be a real nuisance in our region. Avoid planting Geraniums near fennel, as it can inhibit their growth.