Geranium in Zone 6A — Great Plains

Geraniums bring a burst of color to our Great Plains gardens, adding beauty to beds and containers. They are fairly easy to grow, offering continuous blooms throughout our long, sunny days. Plus, their fragrance can help deter some garden pests, making them a practical and pretty addition to any yard.

We know our Great Plains climate can be unpredictable, with extreme temperature swings and the occasional bout of drought. But with a little planning and attention to timing, you can absolutely enjoy vibrant geraniums. Our 188-day growing season gives you a solid window to work with.

Starting geraniums from seed indoors is possible, but be warned – they are SLOW. If you're patient, give it a shot. Starting seeds indoors from late January through mid February, about 12 weeks before our typical last frost, gives them a head start.

Use seed trays with a good seed-starting mix, and keep them consistently warm (around 70-75°F) and well-lit. A heat mat and grow lights really help. Bottom watering is key to avoid damping off – set the tray in a shallow dish of water and let the soil soak it up from the bottom. Just remember that our spring weather can be variable, so be ready to adjust your plans if we get a late cold snap.

For most Plains gardeners, buying geranium starts is the easiest route. If you did start your own, or you bought starts, transplant them outdoors from late April through late May, after the risk of frost has passed.

Harden off your seedlings for about a week before transplanting. Gradually expose them to outdoor conditions, starting with just a few hours a day. Plant them 10-12 inches apart in well-draining soil. Keep an eye on the forecast – we can still get some wild temperature swings that time of year.

Watering is crucial for geraniums in our Great Plains climate. While they aren't drought-tolerant, they also hate soggy feet. Aim to keep the soil consistently moist, but never waterlogged.

During our hot summer months, you'll likely need to water every few days, maybe even daily if they're in containers and it hasn't rained. Stick your finger about 2 inches deep into the soil – if it feels dry, it's time to water. A good soaking of about an inch of water per week is usually sufficient, but adjust based on rainfall.

Water at the base of the plant to avoid getting the foliage wet, which can encourage fungal diseases in our low-to-moderate humidity. Yellowing leaves are a sign of overwatering, while wilting leaves indicate underwatering. A layer of mulch around the base of the plants helps retain moisture and regulate soil temperature, which is especially important during our extreme weather.

Deadheading is essential for keeping your geraniums blooming throughout the season. Simply pinch or snip off the faded flower clusters right where the stem meets the main plant.

Throughout the summer, if you notice any stems getting leggy, pinch them back to encourage bushier growth. As we approach our first frost around mid- October, stop deadheading to allow the plant to prepare for dormancy, or simply bring them indoors if you want to try overwintering them.

Geraniums aren't typically "harvested" in the traditional sense. Instead, enjoy their vibrant blooms in your garden from early July through late August, about 70 days after transplanting.

The "harvest" is really about maintaining the plant for continuous flowering. Regularly remove faded blooms – this not only keeps the plant looking tidy but also encourages it to produce more flowers.

As our first frost approaches around mid- October, you can either let the plants die back naturally or bring them indoors to overwinter. If you choose to overwinter them, cut them back significantly and place them in a cool, dark location with minimal watering.

Here are some common problems you might encounter with geraniums in the Great Plains:

Botrytis Blight

• What it looks like: Gray mold on leaves, stems, and flowers, especially during cool, damp periods.
• What causes it: A fungal disease that thrives in humid conditions and poor air circulation. While our humidity is generally low, prolonged wet spells can create favorable conditions.
• How to fix/prevent it: Remove infected plant parts promptly. Improve air circulation by spacing plants adequately. Avoid overhead watering. Use a fungicide if the problem is severe.

Geranium Budworm

• What it looks like: Holes in buds and flowers, chewed leaves, and small green caterpillars (budworms) present on the plant.
• What causes it: These pests feed on geraniums, causing damage to buds, flowers, and foliage.
• How to fix/prevent it: Handpick caterpillars when you see them. Use insecticidal soap or Bacillus thuringiensis (Bt) as a preventative measure or to control infestations.

Edema

• What it looks like: Small, water-soaked blisters or bumps on the undersides of leaves. These blisters can turn brown or corky over time.
• What causes it: Edema is caused by an imbalance of water uptake and transpiration. It occurs when the roots take up water faster than the leaves can release it through transpiration, often during cool, cloudy weather or when the soil is consistently wet.
• How to fix/prevent it: Improve drainage to prevent waterlogged soil. Ensure good air circulation around the plants. Avoid overwatering, especially during cool periods.

Great Plains Specific Challenges: Our hot, dry summers can stress geraniums, making them more susceptible to pests and diseases. Variable rainfall means you need to be vigilant about watering, adjusting your schedule based on the weather. Wind protection is also essential to prevent damage to stems and flowers, especially during strong Plains winds.

Geraniums make great companions for several plants in the Great Plains garden. Plant them near tomatoes and peppers, as their scent can help repel certain pests like tomato hornworms and aphids. They also pair well with corn, providing some ground cover and potentially deterring some pests that bother corn. Roses also benefit from geraniums nearby, as they can help deter Japanese beetles. Avoid planting geraniums near fennel, as fennel can inhibit their growth.