Geranium in Zone 6B — Pacific Northwest

Geraniums are a fantastic choice for adding vibrant color to your Pacific Northwest garden. They thrive in our mild summers and cool nights, offering a long season of blooms. Plus, their versatility in containers, hanging baskets, and garden beds makes them a perfect fit for our often-compact urban gardens.

While we might struggle a bit to get the same heat as other regions, geraniums are surprisingly resilient and perform beautifully when timed right. Our 162-day growing season gives you ample opportunity to enjoy these beauties, especially if you start them indoors or grab some starts from a local nursery.

Starting geraniums from seed indoors is possible, but it can be a slow process. If you're patient and want a specific variety, starting seeds indoors from mid-February through early March (about 12 weeks before transplanting) is the way to go.

Use seed trays with a good seed-starting mix and provide consistent warmth, ideally around 70-75°F. A heat mat can be helpful, especially with our overcast spring days. Bottom watering helps prevent damping off, which can be a problem in our wet springs. Once seedlings emerge, give them plenty of light—a grow light is beneficial in the PNW.

Transplanting geraniums outdoors should happen from mid-May through mid-June, once the danger of frost has passed. Given that we can still have a late cold snap, it's worth keeping an eye on the forecast. Before planting, harden off your seedlings by gradually exposing them to outdoor conditions for about a week.

Plant them 10-12 inches apart in well-draining soil. Honestly, though, buying starts from a local nursery is often the easiest and most reliable way to get a head start with geraniums here.

Geraniums need moderate watering, and it's crucial not to overdo it, especially with our sometimes-damp springs. Let the soil dry slightly between waterings. Overwatering can easily lead to stem rot, a common issue in our climate.

During our dry summer months, water deeply about once a week, providing roughly an inch of water. Use the finger test: stick your finger about 2 inches into the soil. If it feels dry, it's time to water. Aim to water at the base of the plant to avoid wetting the foliage, as this can encourage fungal diseases in our mild climate.

Signs of underwatering include wilting leaves and dry soil. Overwatering, on the other hand, can cause yellowing leaves and potentially stem rot. A layer of mulch around the base of the plants can help retain moisture and keep the soil temperature consistent, but don't pile it up against the stems.

Regular pruning is key to keeping your geraniums blooming and looking their best. Deadhead spent flower clusters as soon as they start to fade. This encourages the plant to produce more blooms instead of putting energy into seed production.

Throughout the growing season, pinch back any leggy stems to promote bushier growth. As the first frost approaches in early October, you can bring your geraniums indoors to overwinter them, or simply compost them and start fresh next year.

While you're not exactly "harvesting" geraniums for food, you are harvesting beauty! Expect your geraniums to start blooming from late July through mid-September, about 70 days after transplanting.

Enjoy the flowers in your garden and cut them for bouquets if you like. The best way to encourage continued flowering is to deadhead regularly. Remove faded blooms as soon as you see them to keep the plant looking tidy and to encourage new growth.

As the growing season winds down and the first frost approaches in early October, you can take cuttings to propagate new plants or bring your favorite geraniums indoors to overwinter.

Here are some common problems you might encounter with geraniums in the Pacific Northwest:

Botrytis Blight

• What it looks like: Gray mold on leaves, stems, and flowers.
• What causes it: High humidity and cool temperatures, especially during our wet springs and falls.
• How to fix/prevent it: Improve air circulation by spacing plants adequately. Remove and destroy infected plant parts promptly. Avoid overhead watering, and consider using a fungicide if the problem is severe.

Geranium Budworm

• What it looks like: Small caterpillars that bore into flower buds, causing them to fail to open or to open with damaged petals.
• What causes it: Moths lay eggs on the plants, and the larvae (budworms) hatch and feed on the buds.
• How to fix/prevent it: Inspect plants regularly for budworms. Handpick and destroy them. Use row covers to prevent moths from laying eggs on your plants. 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, poor drainage, and cool temperatures. The plant takes up water faster than it can transpire, causing cells to rupture.
• How to fix/prevent it: Improve drainage by amending the soil with compost or other organic matter. Water less frequently, allowing the soil to dry out slightly between waterings. Ensure good air circulation around the plants.

Pacific Northwest Specific Challenges: Our mild heat and dry-summer humidity can actually be beneficial for geraniums, reducing the risk of some fungal diseases common in hotter, more humid climates. However, our wet springs can make them susceptible to botrytis blight and edema if drainage is poor. Be mindful of watering and provide good air circulation to keep your geraniums healthy and thriving.

Geraniums make excellent companions for several plants in the Pacific Northwest garden. They are known to deter certain pests, benefiting:

• Tomatoes: Geraniums can help repel tomato hornworms and other pests that commonly attack tomatoes.
• Peppers: Similar to tomatoes, geraniums can offer some protection against pests that target peppers.
• Corn: Geraniums may deter corn earworms, which can damage corn crops.
• Roses: Geraniums are believed to deter Japanese beetles, a common rose pest.

Avoid planting geraniums near plants that prefer consistently moist soil, as geraniums thrive with slightly drier conditions.