The ‘Royal Candles’ cultivar of Veronica spicata, often referred to as Spike Speedwell, is a perennial prized by gardeners for its reliable performance and vibrant color. This plant is known for its relatively compact, upright, and bushy growth habit, typically reaching heights between 10 to 18 inches. The plant produces dense, slender flower spikes of deep blue-purple that rise above a tidy mound of dark green, lance-shaped foliage. Its long bloom season, extending from late spring well into mid-summer, makes it a popular choice for adding vertical structure and sustained color to garden borders and containers.
Selecting the Best Location
Establishing the correct environmental conditions is the first step in ensuring the long-term health of Royal Candles Veronica. The plant performs best when situated in a location that receives full sun, meaning at least six hours of direct sunlight each day. While it can tolerate some light shade, especially in hotter southern climates, insufficient light may lead to stretched, floppy growth and a reduction in the number of blooms.
The root system requires average, well-draining soil to prevent issues related to excessive moisture retention. Although the plant appreciates consistent moisture during the establishment phase, avoid planting in heavy clay or areas prone to waterlogging. Veronica spicata is hardy across USDA zones 3 through 8, making it suitable for a wide range of temperate climates. Maintain optimal spacing of 9 to 15 inches between plants to allow for adequate air circulation, which helps manage potential humidity problems.
Routine Watering and Feeding
Consistent moisture is beneficial during the first growing season as the plant establishes its root structure. Once established, Royal Candles Veronica demonstrates a degree of drought tolerance, though it thrives best when the soil is kept evenly moist. A good guideline is to water deeply when the top two to three inches of soil feel dry to the touch, ensuring the entire root zone receives hydration.
Overwatering should be avoided, especially in winter, as perpetually saturated soil can lead to root damage. This perennial is considered a moderate feeder and does not require extensive fertilization in average garden soil. Applying a slow-release, balanced granular fertilizer once in the early spring, as new growth emerges, is sufficient to support its bloom cycle. Avoid applying excessive nitrogen, as this encourages leaf growth at the expense of flower production.
Managing Growth Through Pruning
Structural management is primarily focused on encouraging a prolonged and abundant flowering period throughout the season. The most common technique is deadheading, which involves removing the spent flower spikes as soon as the blooms fade. Cutting the faded spike back to a set of healthy leaves stimulates the plant to produce new flower stems, often resulting in a second or even third flush of blooms.
When the plant finishes its main bloom cycle and the foliage begins to look worn, a more comprehensive shearing can be performed. Cutting the plant back to its basal foliage—the low cluster of leaves at the base—helps tidy its appearance. Gardeners may also leave spent flower heads standing through the winter for structural interest before cutting them back completely in early spring.
Clumps that become overgrown after several years may begin to show reduced vigor and flowering. Dividing the plant every two to three years helps rejuvenate the growth and maintain performance. This task is best accomplished in the early spring before active new growth begins. Dig up the clump and separate it into smaller sections, ensuring each has healthy roots and foliage, then replant them.
Addressing Pests and Diseases
Royal Candles Veronica is a robust, low-maintenance perennial that rarely suffers from severe pest or disease issues. The most common ailment is powdery mildew, a fungal disease that appears as a white, dusty coating on the leaves. This condition is often a symptom of poor air circulation, high humidity, or planting specimens too close together.
Non-chemical management of powdery mildew involves improving air flow around the plants and avoiding overhead watering, which leaves foliage wet for extended periods. Simple pests such as aphids or spider mites may occasionally appear on new growth or flower buds. Manage these by spraying affected areas with a strong jet of water or applying an insecticidal soap if populations become dense.