Long leaf speedwell (Veronica longifolia)
Veronica longifolia, Long leaf speedwell, is a showy June-September bloomer known for spikes of lilac blue flowers in USDA zones 4-8.
Complete Plant Information
Overview
Veronica longifolia, commonly known as long-leaf speedwell, is an excellent vertical accent for the perennial border. This clump-forming herbaceous perennial provides striking spikes of color from mid-summer well into early autumn. Gardeners value its reliable performance and attractive foliage, which forms a neat base for the towering flower stems.
Native to various parts of Europe and Asia, this plant thrives when given consistent moisture and plenty of sunlight. While it adapts to light shade, full sun encourages the best flower production and sturdier stems. The mature height of 2 to 4 feet makes it an ideal mid-to-back border plant capable of complementing taller shrubs or acting as a commanding vertical element.
The main appeal stems from the abundant, slender racemes of small, funnel-shaped lilac-blue flowers that appear prolifically. Long leaf speedwell is highly functional, offering excellent material for cutting arrangements while reliably deterring common garden pests like rabbits and deer.
Fast Facts
- Plant Family: Plantaginaceae
- Plant Type: Herbaceous perennial
- Native Range: Northern, eastern, and central Europe
- Hardiness Zones: USDA Zones 4-8
- Size at Maturity:
- Height: 2-4 ft
- Spread: 1-2 ft
- Bloom Time: June to September
- Bloom Description: Lilac blue
- Sun Exposure: Full sun
- Water Needs: Medium
- Maintenance Level: Medium
How to Grow
Veronica longifolia establishes best when planted in spring or fall into evenly moist, well-drained soil. While it prefers full sun for the strongest growth, it will tolerate light shade, though this may result in slightly weaker stems. Ensure planting sites offer rich loams, as the plant is intolerant of dry soils and struggles in poor, depleted ground.
Watering should be consistent, maintaining medium moisture levels, especially during dry spells, as this speedwell dislikes drying out. Maintenance is fairly straightforward; the primary ongoing task is deadheading. Promptly remove spent flower spikes to encourage sporadic rebloom extending the floral display toward September.
For optimal longevity, this perennial requires rejuvenation every three years. Lift, divide, and replant the clumps, amending the soil with compost and manure during this process. Be mindful that overly rich soils or excessive shade can lead to weak, floppy growth, necessitating staking if support is required.
Landscape Uses
Long leaf speedwell adds wonderful architectural structure, making it perfect for structured borders or looser, romantic cottage gardens. Its upright habit is essential for creating vertical rhythm within a mass planting scheme. Plant Veronica longifolia in drifts of three or more specimens to maximize the impact of the stacked, lilac-blue flowers.
This plant excels at edging pathways when kept trimmed, though its 4-foot potential makes it best suited as a mid-border element where it can anchor shorter plantings like edging material or groundcovers. Consider companion planting with plants that appreciate similar moisture levels, such as Astilbes or hardy Geraniums, to create beautiful textural contrasts.
Its strong vertical lines contrast beautifully against plants with broad, mounding habits, allowing gardeners to play with height and form. The vertical presence of long-leaf speedwell ensures that the border remains interesting even when other summer flowers begin to fade.
Standout Features
Flower Qualities
- Showy
- Good Cut
Noteworthy Characteristics
Veronica longifolia, commonly known as long-leaf speedwell, is a clump-forming herbaceous perennial that typically grows to 2-4’ tall with a 1-2’ spread on stems clad with short-stalked, lanceolate to pointed ovate, toothed, medium green leaves (to 3” long). Stems are topped in late spring to early summer by a showy bloom of small but abundant funnel-shaped, lilac-blue flowers in slender, crowded, spike-like terminal racemes to 12” long. The common name speedwell probably refers to an ancient herbal medicinal use of plant parts in curing ailments rapidly.
Tolerances
- Rabbit
- Deer
Potential Problems
Generally, Veronica longifolia is robust and avoids serious insect or disease issues. The most significant cultural concern is stem support; taller specimens, especially those grown in less than full sun or too rich soil, may require staking to prevent flopping. Gardeners should regularly monitor for powdery mildew, a common fungal issue, particularly if air circulation is poor or overhead watering encourages leaf wetness. Good plant spacing and pruning out older interior growth can help mitigate mildew development.
Frequently Asked Questions
What hardiness zones is Long leaf speedwell suitable for?
Long leaf speedwell is well-suited for USDA Hardiness Zones 4 through 8.
How large does Veronica longifolia grow?
This perennial typically reaches a mature height of 2 to 4 feet, with an average spread between 1 and 2 feet.
What sun exposure does Veronica longifolia need?
This plant thrives best in full sun conditions, though it can tolerate light shade.
When does Long leaf speedwell bloom?
Veronica longifolia produces its showy lilac blue blooms primarily from June to September.
Conclusion
The visual impact and reliability of Veronica longifolia make it an indispensable component of the perennial garden, especially for its vivid lilac-blue spikes and pest resistance. If you seek vertical interest that marries well with cottage garden aesthetics, the Long leaf speedwell is an excellent choice. Before planting, ensure your site offers medium moisture and full sun exposure to guarantee the healthiest structure.
Propagation Tips
Propagating Long leaf speedwell is achievable through several standard perennial methods. Division is the most common and effective technique for maintaining established clumps; lift the plant every third year, typically in spring or fall, gently separate the root mass, and replant immediately. Alternatively, gardeners can attempt propagation via cuttings taken from semi-hardwood stems during the summer months. For those starting new plants en masse, seed sowing is also a viable, though slower, propagation route for Veronica longifolia.
Companion Planting
Successful companion planting with Veronica longifolia relies on matching its need for consistent moisture and well-drained conditions. Pair it with other mid-to-back border favorites that enjoy similar cultural demands, such as Russian Sage (Perovskia atriplicifolia) for color contrast, or tall ornamental grasses for textural variety. Avoid placing it immediately next to plants that demand deep shade or prolonged dry periods, as this will stress the speedwell and result in floppy growth.
