Geranium in Zone 7A — Midwest

Geraniums are a Midwest garden favorite, bringing vibrant color to our yards and containers all summer long. Their cheerful blooms and ease of care make them a rewarding choice for both novice and experienced gardeners in our region. Plus, they pair well with so many other plants we love to grow.

While Midwest weather can be unpredictable, with our cold winters and occasional summer heat spells, Geraniums are surprisingly resilient. Starting them indoors or buying established plants gives them a head start, ensuring you enjoy their beauty throughout our 193-day growing season.

Starting Geranium seeds indoors in the Midwest is definitely doable, but be warned: they are slow growers! If you're patient and enjoy the process, go for it. Otherwise, buying starts from a local nursery might be a better bet.

If you're starting from seed, aim to sow them from late January through mid February, about 12 weeks before you plan to transplant them outdoors. Use seed trays with a good seed-starting mix and provide consistent warmth and light. Bottom watering helps prevent damping off, which can be a problem in our sometimes-humid Midwest springs.

Remember, our springs can be a bit variable, so don't rush to get them outside too early. A little extra time indoors under grow lights will pay off in the long run.

Transplanting Geraniums outdoors in the Midwest should happen from late April through late May, once the danger of frost has passed. Keep an eye on the forecast – we can sometimes get a late frost that surprises you.

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 fertile soil. Honestly, though, buying established plants from a local nursery is often the easiest and most reliable way to get a jump start on Geranium season here.

Geraniums in the Midwest need moderate watering, but they definitely don't like soggy feet. Let the soil dry out slightly between waterings – about the top inch or two. Overwatering is a surefire way to cause stem rot, especially with our moderate-to-humid summers.

During the hotter parts of the summer, you'll likely need to water them a couple of times a week. Stick your finger about 2 inches deep into the soil. If it feels dry, it's time to water. Aim for about an inch of water per week, either from rain or irrigation. 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 turn yellow and droop, you're probably overwatering. If they wilt and the soil feels dry, you're underwatering. A layer of mulch around the base of the plants helps retain moisture and keeps the soil cool during those summer heat spells.

Pruning Geraniums is simple and keeps them looking their best. The main thing is to deadhead spent flower clusters. This encourages the plant to produce more blooms throughout the season.

Simply snip off the faded flower heads just below the point where they join the stem. You can do this throughout the growing season, from spring through fall. If you notice any leggy stems, pinch them back to encourage bushier growth. As the first frost approaches in mid- October, you can give your Geraniums a final trim to tidy them up before bringing them indoors (if you plan to overwinter them).

Geraniums are primarily grown for their beautiful flowers, so "harvesting" is more about maintaining their appearance and encouraging more blooms. You can expect your Geraniums to start flowering in early July and continue through late August, sometimes even longer if the weather cooperates.

The best way to "harvest" is to regularly remove faded or dead flowers. This keeps the plant looking neat and tidy, and it also encourages the plant to produce more blooms. Simply snip off the faded flower heads with clean scissors or pruning shears.

As the first frost approaches in mid- October, you can either let your Geraniums go, or you can try to overwinter them indoors. If you choose to overwinter them, give them a good trim before bringing them inside and place them in a sunny location.

Here are some common problems you might encounter with Geraniums in the Midwest:

Botrytis Blight

• What it looks like: Grayish-brown fuzzy mold on flowers, leaves, and stems.
• What causes it: High humidity and poor air circulation, which are common in Midwest summers.
• How to fix/prevent it: Remove infected plant parts, improve air circulation by spacing plants properly, and avoid overhead watering. A fungicide may be necessary in severe cases.

Geranium Budworm

• What it looks like: Small holes in buds and flowers, often with caterpillar droppings nearby.
• What causes it: Caterpillars feeding on the plant.
• How to fix/prevent it: Handpick caterpillars, use Bacillus thuringiensis (Bt) spray, and monitor plants regularly.

Edema

• What it looks like: Small, raised blisters or bumps on the undersides of leaves.
• What causes it: Excessive moisture in the soil and cool temperatures, which can happen during our variable springs.
• How to fix/prevent it: Improve drainage, avoid overwatering, and provide good air circulation.

Midwest Specific Challenges: The moderate-to-hot heat, moderate-to-humid humidity, and wet-summer rainfall in the Midwest can create ideal conditions for fungal diseases like botrytis blight. Be sure to provide good air circulation and avoid overwatering to keep your Geraniums healthy and thriving.

Geraniums make great companions for several plants in the Midwest garden. They are known to repel certain pests, which benefits:

• Tomatoes and Peppers: Geraniums can help deter tomato hornworms and pepper weevils.
• Corn: Geraniums can help repel corn earworms.
• Roses: Geraniums can help deter Japanese beetles.

Avoid planting Geraniums near plants that require very dry conditions, as their moderate watering needs may not be compatible.