‘Frank Holmes’ Dahlia is a popular garden choice, known for its captivating blooms that bring vibrant color to any landscape. Cultivating this dahlia can be a rewarding experience.
Understanding ‘Frank Holmes’ Dahlia
The ‘Frank Holmes’ dahlia produces vivid violet or lilac flowers, often with a darker purple wash at the petal tips. These blooms are characterized by their perfectly round, compact pompon form, typically measuring 1 to 2 inches in diameter. This dahlia grows as a bushy plant, reaching heights of up to 40 inches. It blooms prolifically from mid-summer until the first autumn frost.
Planting ‘Frank Holmes’ Dahlia
Planting ‘Frank Holmes’ dahlia tubers requires an appropriate site. These plants thrive in full sunlight and prefer a sheltered location. The soil should be rich, well-drained, and slightly acidic (pH 6.5-7). Incorporating organic matter like compost or well-rotted manure before planting enriches the soil and improves drainage.
Plant after the last frost, when soil temperature reaches at least 60°F (15°C). Dig a 4 to 6-inch deep hole. Place the tuber horizontally with the eye, or growing point, facing upwards, then cover with a few inches of soil. Space tubers 12 to 18 inches apart for adequate growth and air circulation. After planting, soak thoroughly to settle the soil, but avoid overwatering until shoots emerge.
Ongoing Care for ‘Frank Holmes’
Consistent watering is important for ‘Frank Holmes’ dahlias once they have sprouted and become established. They require deep watering, reaching 8 to 10 inches into the soil, typically two to three times per week, or more frequently during hot, dry periods. Hand watering often proves insufficient, so using soaker hoses or drip irrigation is recommended for effective moisture delivery to the roots. Checking the soil moisture by feeling the top 2-3 inches for dryness helps determine when to water.
Fertilization supports robust growth and prolific blooming. Dahlias benefit from a low-nitrogen fertilizer (e.g., 5-10-10 or 5-10-15) to promote flower development. Apply fertilizer approximately 30 days after planting, then every three to four weeks throughout the growing season. Deadhead spent blooms by cutting the stem back to the next set of leaves to encourage continuous flowering. Since ‘Frank Holmes’ can grow tall, staking is often necessary to support brittle stems and heavy blooms, preventing breakage. Place stakes, such as a 6-foot hardwood stake, near the plant at planting time, driving them at least 12 inches deep, and tie stems to them as they grow.
Overwintering ‘Frank Holmes’ Tubers
In regions with winter frost, ‘Frank Holmes’ dahlia tubers must be dug up and stored. Dig after the first hard frost blackens the foliage, but before the ground freezes solid, allowing tubers to cure in the soil for one to two weeks. After lifting, gently remove excess soil by brushing or rinsing, taking care not to damage the skin.
Once cleaned, cure tubers in a cool, dry, dark place with good air circulation for several days to two weeks; this toughens the skin and prevents rot. Store dried tubers in a cool, dark, frost-free environment (38-50°F / 4-10°C), such as an unheated basement or garage. Maintaining 75-85% humidity helps prevent shriveling. Pack tubers in a storage medium like peat moss, vermiculite, or wood shavings, ensuring space for air circulation. Regularly inspect stored tubers throughout winter, removing any showing signs of rot or mold.
Troubleshooting Common Dahlia Issues
Dahlias, including ‘Frank Holmes’, can encounter various issues, with common problems often stemming from environmental factors or pests and diseases. Powdery mildew, a fungal disease, appears as a white, powdery substance on leaves and stems, especially in warm, humid conditions. Improving air circulation, reducing overhead watering, and removing affected parts can help manage it; natural fungicides like neem oil or baking soda solutions may also be applied.
Botrytis blight, or gray mold, manifests as grayish-brown fuzzy mold on flowers, leaves, and stems, particularly during cloudy, wet weather. Promptly removing infected plant parts, improving air circulation, and avoiding excessive humidity are key preventative measures. Pests like slugs, earwigs, and spider mites can also affect dahlias, causing damage such as chewed foliage or stippling. Addressing these pests often involves physical removal, traps, or appropriate horticultural sprays. Regular inspection allows for early detection and intervention, important for maintaining plant health.