Geranium in Zone 5B — Mid-Atlantic

Geraniums are a classic for a reason, and they're a fantastic choice for adding vibrant color to your Mid-Atlantic garden. Their bright blooms and relatively easy care make them a rewarding addition to containers, beds, and borders. Plus, they attract pollinators, adding to the health and beauty of your outdoor space during our humid summers.

Our four seasons can be a bit unpredictable, but don't let that deter you. With a 178-day growing season, we have ample time to enjoy geraniums. Just pay attention to the usual weather quirks and get your timing right.

Starting geraniums from seed indoors is possible, but it can be a slow process. For many Mid-Atlantic gardeners, buying established starts from a local nursery is the easier route. However, if you're keen to start from seed, aim for early to late February, roughly 12 weeks before you plan to transplant outdoors.

Use seed trays with a good seed-starting mix and provide consistent warmth and bright light, ideally from a grow light. Bottom watering helps prevent damping off – just set the tray in a shallow dish of water until the surface of the soil is moist. Keep in mind that our spring weather can be variable, so be prepared to adjust your indoor growing conditions as needed.

Transplant your geraniums outdoors from early May through early June, once the danger 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 sun and wind.

Plant them 10-12 inches apart in a sunny to partially shaded spot with well-drained soil. Keep in mind that we can get unexpected late frosts, so watch the forecast and be ready to cover your plants if necessary. Given how slow they are from seed, don't hesitate to buy starts; it's common practice around here!

Geraniums need moderate watering, but overwatering is a common mistake, especially with our humid summers. Let the soil dry out slightly between waterings to prevent stem rot. They can tolerate the heat better than some other flowers, but they still need consistent moisture, especially when getting established.

During the spring and fall, when temperatures are cooler and rainfall is more frequent, you might only need to water once a week, if at all. In the heat of our humid summers, you may need to water every other day, or even daily if they're in containers. Use the finger test: stick your finger about two inches into the soil. If it feels dry, it's time to water. Aim for about an 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 climate. Signs of underwatering include wilting and dry, crispy leaves. Overwatering can cause yellowing leaves and stem rot. A layer of mulch, like shredded bark, can help retain moisture and suppress weeds, but be sure to keep it away from the stems to prevent rot.

Deadheading is key to keeping your geraniums blooming throughout the season. Regularly remove spent flower clusters by snipping them off at the base of the stem. This encourages the plant to produce new flowers instead of putting energy into seed production.

If your geraniums start to look leggy, pinch back the stems to encourage bushier growth. Simply trim the tips of the stems to promote branching. As the first frost approaches around mid- October, you can bring your geraniums indoors to overwinter, or take cuttings to propagate new plants for next year.

Geraniums aren't really about a traditional harvest, but more about enjoying their beauty throughout the growing season. Expect your geraniums to start blooming around mid-July through late August, about 70 days after starting from seed or transplanting.

The "harvest" is really about enjoying the flowers in your garden and removing faded blooms to keep the plants looking neat and tidy. Removing spent flowers encourages continuous blooming, so keep an eye on them.

As the first frost approaches in mid- October, you can either let your geraniums fade with the season or bring them indoors to overwinter. Alternatively, take cuttings before the frost hits to propagate new plants for next year.

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

Botrytis Blight

• What it looks like: Grayish-brown fuzzy 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 can be particularly problematic.
• How to fix/prevent it: Improve air circulation by spacing plants properly and pruning out dead or diseased foliage. Avoid overhead watering and apply a fungicide if necessary.

Geranium Budworm

• What it looks like: Holes in buds and flowers, often with dark droppings nearby.
• What causes it: Caterpillars of moths that lay their eggs on geraniums.
• How to fix/prevent it: Inspect plants regularly for caterpillars and handpick them off. Bacillus thuringiensis (Bt) is an effective organic control option.

Edema

• What it looks like: Small, blister-like bumps on the undersides of leaves.
• What causes it: Overwatering and poor drainage, leading to waterlogged soil. This is more common during periods of heavy rainfall.
• How to fix/prevent it: Ensure good drainage and avoid overwatering. Allow the soil to dry out slightly between waterings.

Mid-Atlantic Specific Challenges: Our moderate-to-hot summers and humid conditions can make geraniums susceptible to fungal diseases. Even rainfall, while generally a blessing, can also contribute to overwatering issues if drainage isn't adequate. Keep a close eye on your plants and adjust your watering and maintenance practices as needed.

Geraniums make excellent companions for several plants in the Mid-Atlantic garden:

• Tomatoes, Peppers, Corn: Geraniums are said to repel certain pests that commonly attack these vegetables, such as tomato hornworms and aphids.
• Roses: Geraniums can help deter Japanese beetles, which are a major nuisance for rose growers in our region.

Avoid planting geraniums near:

• (none specified)

There are no specific plants that are known to be bad companions for geraniums.