Geranium in Zone 7A — Mid-Atlantic

Geraniums are a classic choice for Mid-Atlantic gardens, bringing vibrant color and a touch of old-fashioned charm to our porches, patios, and flower beds. Their versatility shines in containers, borders, and even hanging baskets, adding beauty throughout our four seasons. Plus, they're relatively easy to grow, offering a satisfying reward for even novice gardeners in our region.

While our humid summers and variable spring weather can present challenges, the extended growing season (around 208 days) in our Zone 7A gives you plenty of time to get your geraniums established. Starting at the right time and providing proper care will help them thrive here in the Mid-Atlantic.

Starting geraniums from seed indoors is possible, but honestly, most of us Mid-Atlantic gardeners find it easier to buy established plants from a local nursery. Geraniums can be slow to get going from seed. However, if you're keen to start your own, aim to sow seeds indoors from mid January through early February, roughly 12 weeks before you plan to transplant them outdoors.

Use seed trays with a good quality seed-starting mix. Keep the soil consistently moist (bottom watering helps prevent damping-off) and provide warmth and plenty of light, either from a sunny window or a grow light. Remember our spring weather can be unpredictable, so starting indoors gives you a head start.

Transplant your geranium seedlings outdoors from mid April through mid May, after the risk of frost has passed. Before planting, harden off your seedlings by gradually exposing them to outdoor conditions for about a week. This helps them adjust to the sunlight and temperatures.

Space your geraniums about 10-12 inches apart to allow for good air circulation, which is especially important with our humid Mid-Atlantic summers. If you opted for starts, you'll be enjoying the beauty of your geraniums much sooner than if you started from seed.

Geraniums in the Mid-Atlantic need moderate watering to thrive. The key is to let the soil dry out slightly between waterings. Overwatering is a common mistake, as it can lead to stem rot, a real problem in our humid climate.

During the warmer months, especially in July and August when we're experiencing our moderate-to-hot summer heat, check the soil moisture regularly. 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, either from rainfall or irrigation. Water at the base of the plant to avoid wetting the foliage, which can encourage fungal diseases in our humid environment.

Signs of underwatering include wilting leaves and dry, crispy edges. Overwatering, on the other hand, can cause yellowing leaves and a mushy stem. A layer of mulch around your geraniums helps retain moisture and suppress weeds, but be careful not to pile it up against the stems, as this can also contribute to rot.

Pruning geraniums is simple and essential for keeping them blooming throughout the season. Deadhead spent flower clusters regularly by snipping them off just above a leaf node. This encourages the plant to produce more flowers instead of putting energy into seed production.

If your geraniums start to look leggy, pinch back the stems to encourage bushier growth. Simply snip off the tips of the stems just above a leaf node. As the first frost approaches in late October, stop deadheading so the plant can begin to harden off for the winter.

Geraniums are primarily grown for their ornamental value, so harvesting is more about maintaining their appearance and encouraging continued blooming. You can expect your geraniums to start flowering from late June through mid August, about 70 days after planting.

The best way to "harvest" is to regularly remove faded or dead blooms. This not only keeps the plant looking tidy but also encourages it to produce more flowers throughout the season. Simply snip off the spent flower heads just above a leaf node. As the first frost approaches in late October, you can bring potted geraniums indoors to overwinter, although they may not flower as prolifically during the winter months.

Here are some common problems you might encounter with geraniums in the Mid-Atlantic:

Botrytis Blight

• What it looks like: Grayish-brown mold on leaves, stems, and flowers.
• What causes it: High humidity and poor air circulation create ideal conditions for this fungal disease. Our humid summers in the Mid-Atlantic make geraniums particularly susceptible.
• How to fix/prevent it: Improve air circulation by spacing plants properly and pruning out crowded growth. Remove and destroy infected plant parts. Apply a fungicide if necessary.

Geranium Budworm

• What it looks like: Holes in buds and flowers, often with dark droppings nearby.
• What causes it: These caterpillars feed on geranium buds and flowers, causing significant damage.
• How to fix/prevent it: Handpick caterpillars from plants. Use Bacillus thuringiensis (Bt) as a biological control.

Edema

• What it looks like: Small, raised blisters or bumps on the undersides of leaves.
• What causes it: Edema is caused by an irregular water supply where the roots take up more water than the plant can transpire, causing cells to burst. This is common during periods of cool, wet weather in the spring.
• How to fix/prevent it: Improve drainage and avoid overwatering. Provide good air circulation around plants.

Mid-Atlantic Specific Challenges: Our moderate-to-hot summers and humid humidity, combined with even rainfall, create a challenging environment for geraniums. Proper spacing, good air circulation, and careful watering are essential for preventing fungal diseases. Keep an eye out for pests like geranium budworms, and take action promptly to prevent them from causing significant damage.

Geraniums make excellent companions for many plants in the Mid-Atlantic garden. They pair well with tomatoes, peppers, and corn, as their strong scent can help deter certain pests that bother these vegetables. Roses also benefit from geraniums planted nearby, as they can help repel Japanese beetles, a common nuisance in our region. Avoid planting geraniums near fennel, as it can inhibit their growth.