The Crape Myrtle, a member of the Lagerstroemia genus, is a celebrated deciduous plant known for its vibrant, long-lasting summer blooms. The ‘Double Dynamite’ cultivar (Lagerstroemia indica ‘Whit X’ PP #27,085) is prized for its intense, deep cherry-red flower color. This specific hybrid re-blooms continuously, providing a spectacular display throughout the season. These features, combined with its improved resistance to common diseases, make it a popular landscape choice.
Understanding the Double Dynamite Cultivar and Site Selection
The ‘Double Dynamite’ crape myrtle is a mid-sized variety, maturing to a compact height and width of approximately 8 to 10 feet. Its showy blossoms appear on large panicles, offering a vivid cherry-red hue. New leaves emerge with a purple tint before maturing to a deep green, which provides multi-season visual interest. This cultivar exhibits excellent resistance to powdery mildew and possesses moderate drought tolerance once its root system is fully established.
Selecting the right location is paramount to guaranteeing a successful bloom cycle. This plant demands full sun exposure, requiring a minimum of six to eight hours of direct sunlight each day to support its continuous flowering habit. Plant it in well-draining soil, as waterlogged conditions can quickly lead to root rot. Crape myrtles prefer a slightly acidic to neutral soil pH, ideally ranging between 5.0 and 6.5. The cultivar is cold-hardy and reliably thrives across USDA Plant Hardiness Zones 7 through 10.
Planting and Initial Establishment Techniques
Proper planting begins with preparing a hole that is two to three times wider than the root ball but no deeper. Before placing the plant, gently inspect the root ball and slice through any roots that are tightly circling the perimeter to encourage outward growth. The top of the root ball must sit level with or slightly above the surrounding grade so the root flare remains visible above the soil line. Backfill the hole with the native soil, tamping it lightly to eliminate any large air pockets.
Immediately after planting, water the area deeply and thoroughly to settle the soil around the roots and minimize transplant shock. For the first full growing season, newly planted ‘Double Dynamite’ requires consistent moisture to establish a robust root system. Water deeply once or twice a week, checking that the top two inches of soil dry out slightly between applications. Apply a two-to-three-inch layer of organic mulch over the root zone, keeping the material pulled back several inches from the trunk to prevent moisture buildup and potential disease issues.
Ongoing Seasonal Maintenance
Once the ‘Double Dynamite’ crape myrtle is fully established, its watering needs decrease significantly, reflecting its inherent drought tolerance. During periods without natural rainfall, provide a deep soaking when the top two to three inches of soil feel dry to the touch. This encourages the roots to grow further down into the substrate. Consistent deep watering is more beneficial than frequent shallow sprinkling, which promotes weak, surface-level roots.
Fertilization should be managed carefully to promote blooms rather than excessive leafy growth. Apply a slow-release, balanced granular fertilizer, such as one with a 1-1-1 or similar NPK ratio, in early spring just as new growth begins to emerge. Avoid using high-nitrogen lawn fertilizers near the plant, as this nutrient imbalance can reduce the intensity and quantity of flowers. If desired, deadhead the spent flower panicles in mid-summer, cutting just above the next set of leaves, to encourage a tidier appearance and maximize the repeat bloom potential.
Specialized Care: Pruning and Pest Management
Pruning for ‘Double Dynamite’ is best performed in the late winter or very early spring before the plant breaks dormancy. Because crape myrtles bloom on new wood, this timing ensures that the cuts heal cleanly before the growth cycle begins. Focus on selective thinning of the canopy by removing dead, diseased, or crossing branches. Also remove any suckers, which are small, vigorous shoots that emerge from the base of the trunk or the roots.
Avoid severe topping, which involves cutting main branches back to thick stubs. This incorrect technique ruins the plant’s natural form, leads to weak new growth, and makes the tree more susceptible to disease. Instead, maintain the natural vase shape by cutting branches back to a larger limb, the main trunk, or an outward-facing bud. This intentional pruning technique improves air circulation and sunlight penetration, which prevents common fungal problems.
While the ‘Double Dynamite’ is bred for disease resistance, particularly against powdery mildew, it can still attract certain pests. Aphids are common and can be managed by dislodging them with a strong jet of water or by applying insecticidal soap or neem oil to the affected areas. Scale insects, which appear as small, stationary bumps on the bark, are best treated with a horticultural oil application during the plant’s dormant period in late winter. Timely intervention and proper cultural practices, such as ensuring full sun and good airflow, are the most effective strategies for maintaining the plant’s health.