Geranium in Zone 6B — Mid-Atlantic

Geraniums bring a classic charm to any Mid-Atlantic garden. Their vibrant blooms are perfect for containers, borders, or adding pops of color to your vegetable beds, and they thrive in our four seasons. Plus, their scent can actually help deter some garden pests, making them a useful and beautiful addition.

While we deal with humid summers and occasional deer pressure here in Zone 6B, growing geraniums is very doable with proper timing. Our growing season, usually from early April to late October, gives you plenty of time to enjoy their cheerful flowers. Let's get started!

Starting geraniums from seed indoors is an option, but be warned: they're notoriously slow. If you're up for a challenge, start your seeds indoors from late January through mid February, giving them about 12 weeks to get a head start.

Use seed trays with a good seed-starting mix and keep them consistently warm – around 70-75°F. A heat mat can be helpful. Provide plenty of light, either from a sunny windowsill or a grow light, and don't forget to water from the bottom to prevent damping off. Honestly, though, unless you're after a specific variety, buying established starts from a local nursery in spring is often the easier route.

Transplant your geraniums outdoors from late April through late May, once the danger of frost has passed. Before planting, harden them off by gradually exposing them to outdoor conditions for about a week. This helps them adjust to the temperature swings and sunlight.

Plant them 10-12 inches apart in well-draining soil. Be prepared for some variable weather during this time – we can still get some chilly nights or unexpected downpours in the Mid-Atlantic. You might want to keep some frost cloth handy just in case. Given how slow they are from seed, most of us find it easier to buy established plants from a local nursery.

Geraniums like consistent moisture, but they definitely don't like sitting in soggy soil, which is easy to do with our humid summers here in the Mid-Atlantic. A good rule of thumb is to let the top inch or two of soil dry out between waterings. Stick your finger in the soil to about 2 inches deep to check.

During the hotter months of July and August, you'll likely need to water them a couple of times a week, giving them about an inch of water each time. However, pay attention to the rainfall – with our even rainfall, we often get enough from Mother Nature. It's generally best to water at the base of the plant to avoid getting the foliage wet, which can encourage fungal diseases in our humid climate.

If the leaves start to yellow and droop, you're probably overwatering. If they're wilting and the soil feels dry, you're underwatering. A layer of mulch around the base of the plants can help retain moisture and keep the soil temperature consistent, which is particularly helpful during our hot spells.

Deadheading is key to keeping your geraniums blooming all season long. Throughout the growing season, from early July through late October, regularly remove any spent flower clusters by snipping them off at the base of the stem. This encourages the plant to produce more flowers instead of putting energy into seed production.

If your geraniums start to look leggy (long, bare stems with fewer leaves), you can pinch back the stems to encourage bushier growth. Just snip off the tips of the stems above a leaf node. As the first frost approaches in late October, you can bring your geraniums indoors to overwinter if you want to try to save them for next year, or simply compost them and start fresh in the spring.

Unlike many garden plants, you don't "harvest" geraniums for food. Instead, you harvest their beauty by enjoying their flowers in your garden from early July through late August, and beyond if the weather cooperates. The main thing is to keep them looking tidy by removing faded blooms.

As flowers fade, simply snip them off with clean pruners or scissors. This encourages the plant to produce more blooms, extending the flowering season. Make sure to cut the stem back to a node where new growth will emerge.

As the first frost approaches in late October, consider taking cuttings to propagate new plants indoors over the winter. Otherwise, you can compost the plants and look forward to a fresh start next spring.

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

• Botrytis Blight
• What it looks like: Grayish-brown fuzzy mold on flowers, leaves, and stems.
• What causes it: High humidity and poor air circulation create ideal conditions for this fungal disease. Our humid summers are particularly conducive to botrytis.
• How to fix/prevent it: Improve air circulation by spacing plants properly and pruning out dense growth. Remove and destroy infected plant parts immediately. Apply a fungicide if the problem is severe. Water at the base of the plant to keep foliage dry.
• 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. Insecticidal soap or Bacillus thuringiensis (Bt) can be effective, especially when applied early in the infestation.
• Edema
• What it looks like: Small, blister-like bumps on the undersides of leaves, which can turn brown and corky.
• What causes it: Edema is caused by excessive moisture in the soil and cool temperatures, leading to cells bursting.
• How to fix/prevent it: Improve drainage and air circulation. Avoid overwatering, especially during cool, cloudy weather.

Mid-Atlantic Specific Challenges: Our moderate-to-hot summers and high humidity can create ideal conditions for fungal diseases like botrytis blight. Consistent monitoring and proactive measures are key to keeping your geraniums healthy.

Geraniums are great companions in the Mid-Atlantic garden! Plant them near tomatoes, peppers, and corn. Their scent can help deter certain pests that bother these veggies. They're also lovely planted near roses, helping to protect them from Japanese beetles.

Avoid planting geraniums near fennel, as fennel can inhibit their growth. Otherwise, geraniums are pretty easygoing and get along well with most plants in our gardens.