Phlox hybrid – Mountainside™ ‘Crater Lake’ – Hybrid Spring Phlox
This hybrid Phlox spreads slowly, forming a compressed, groundcover. Small, cool indigo purple flowers cover the plant. One of the first perennials to bloom in spring.
Attracts: Bees, Butterflies
Native to North America
Gritty, slightly alkaline soils are preferred and good drainage is essential. Full sun is essential for performance.
Maintenance Category Easy
Water Category Average
Flower Form Border Plant, Container, Landscape, Mass Planting
Soil Fertility Average Soil, Poor Soil
Soil PH Category Alkaline Soil, Neutral Soil
pH B - pH 5.8 - 6.2, C - pH 6.0 - 6.5
EC (2:1 Extraction Method) 0.8 - 1.3
Fertilization 75 - 200
Light Requirements High
Water Requirements Moderate to Moist
Rooting Out Temperature 65 - 72° Fahrenheit
Growing On Temperature 55 - 72° Fahrenheit
Holding Temperature 40 - 50° Fahrenheit
Planting and Timing Information
Late Spring through Fall Finish. Standard PPP.
Finishing Times [weeks]
4-5" and Quart Pot : 6-8
6" and Gallon Pot : 10-12
7-9" Pot : 10-12
10-12" and Two Gallon Pot :
Pinching and Growth Regulators
Soft Pinch when the plant is 3 to 4 inches tall. The lower the plant breaks the better the plant quality. If flowering is desired, allow 10 to 12 weeks after the onset of long days for flowering. 'Shockwave' is grown for foliage as much as flowers and may have a shorter crop time since flowers are unnecessary for sales.
Pest and Disease Management
General pest and disease practices as listed in notes.
Watch for aphids, spider mites and whiteflies, scout and treat as needed.
Leaf spots and powdery mildew can be problematic.
The Flame series of Phlox is less mildew susceptible than many that are available.
-Quart size plants are sold green rather than in flower.
-Good air circulation, high light levels and watering in the morning will help decrease disease incidence.
-Vernalization will increase plant vigor, decrease time to flower and improve uniformity of flowering.
-'Shockwave' can be used as a foliage interest plant in combinations.
-'Shockwave' performs best with fertilization rates between 75 and 100 ppm.