How to Grow Larkspur in Washington

Larkspur (Delphinium) is a stunning perennial flower that can transform any garden into a vibrant display of color. With its tall spikes adorned with clusters of delicate blooms, larkspur is a favorite among gardeners in Washington. This article will guide you through the essential steps to successfully grow larkspur in your Washington garden, focusing on climate considerations, soil requirements, planting methods, care, and common pests.

Understanding the Climate in Washington

Washington’s climate varies significantly from region to region, with the western part of the state experiencing a temperate maritime climate and the eastern region characterized by a more continental climate.

Western Washington

In western Washington, summers are typically mild and wet, while winters can be cool and damp. Larkspur thrives in this environment but requires careful management to prevent rot due to excessive moisture.

Eastern Washington

Conversely, eastern Washington experiences hotter summers and colder winters. Here, larkspur can be grown successfully, provided it has adequate water during the dry summer months.

Choosing the Right Variety

Before planting larkspur, it’s important to choose the right variety suited for your specific growing conditions. Some popular varieties include:

• Delphinium Pacific Giant: Known for its tall spikes and broad range of colors.
• Delphinium Magic Fountains: A dwarf variety perfect for borders.
• Delphinium Guardian Series: Offers shorter plants with sturdy stems.

Soil Requirements

Larkspur prefers rich, well-drained soil enriched with organic matter. The ideal soil pH for larkspur ranges from 6.0 to 7.0.

Soil Preparation

1. Test Your Soil: Conduct a soil test to determine pH and nutrient levels.
2. Amend as Necessary: If your soil is too acidic or alkaline, amend it accordingly using lime (to increase pH) or sulfur (to decrease pH).
3. Add Organic Matter: Incorporate compost or well-rotted manure into the soil to enhance fertility and improve drainage.

Choosing the Right Location

Sunlight Requirements

Larkspur thrives best in full sun but can tolerate partial shade. In hotter regions of eastern Washington, some afternoon shade may help protect young plants from stress during peak summer heat.

Spacing Considerations

When planning your garden layout, consider spacing your plants adequately to promote air circulation and reduce humidity around them. Space larger varieties about 18-24 inches apart while dwarf varieties can be spaced closer together at about 12-15 inches apart.

Planting Larkspur

Larkspur can be planted either as seeds or as transplants:

Planting Seeds Directly

1. Timing: Sow seeds directly in the garden in late spring (after the last frost) or fall (for winter germination).
2. Preparation: Rake the soil surface to create a fine seedbed.
3. Sowing: Scatter seeds lightly on top of the soil; do not bury them deeply as they require light for germination.
4. Watering: Gently mist the area to keep the seeds moist until they germinate in 10-20 days.

Transplanting Seedlings

If you prefer starting indoors:

1. Seed Starting: Start seeds indoors 8-10 weeks before your last frost date.
2. Transplanting: Once seedlings are about 4 inches tall and after hardening them off for a week, transplant them outdoors following the same spacing guidelines.

Care and Maintenance

Once established, larkspurs are relatively low maintenance but will benefit from regular attention.

Watering

Regular watering is crucial during dry spells, especially during flowering when moisture supports bloom production. Aim for deep watering once a week rather than frequent shallow watering to encourage strong root growth.

Fertilizing

To ensure vigorous growth and abundant blooms:

1. Initial Fertilization: Apply a balanced fertilizer at planting time.
2. Mid-Season Boost: Fertilize again mid-summer using a nitrogen-rich fertilizer to promote lush foliage and flowering.

Pruning and Deadheading

1. Support Stems: Tall varieties may need staking or support to prevent them from falling over.
2. Deadheading: Remove spent flowers regularly to encourage additional blooming.

Winter Care

In Washington’s colder regions:

1. Mulching: Apply a layer of mulch around the base of plants in late fall to protect roots during winter freezes.
2. Cut Back: In late fall or early spring, cut back dead stems to promote new growth.

Common Pests and Diseases

While larkspurs are generally hardy plants, they can be susceptible to certain pests and diseases:

Pests

• Aphids: These small insects can be controlled using insecticidal soap or neem oil.
• Snails and Slugs: Handpicking these pests or using traps can minimize damage.

Diseases

• Powdery Mildew: Ensure good air circulation around plants and avoid overhead watering to reduce humidity levels that promote this fungal disease.
• Botrytis Blight: Proper spacing and removing infected debris can help control this issue.

Companion Planting Ideas

To enhance your garden’s beauty and health, consider companion planting larkspur with other flowers that prefer similar growing conditions:

• Salvia: Their blue flowers complement larkspur beautifully while attracting pollinators.
• Echinacea (Coneflower): These sturdy perennials provide an extended blooming period alongside larkspur.
• Rudbeckia (Black-eyed Susan): Another cheerful addition that pairs well visually with larkspur blooms.

Conclusion

Growing larkspur in Washington is a rewarding endeavor that adds stunning visual interest to gardens while supporting local pollinators. By selecting appropriate varieties, preparing your soil adequately, providing proper care, and managing potential pests and diseases effectively, you can enjoy their majestic blooms year after year.

With these guidelines in hand, you’re ready to cultivate a beautiful display of larkspurs that will thrive within Washington’s diverse climates! Happy gardening!