Astoria Phlox: Production Secrets
October 11, 2012 
The Astoria series offers a wide selection of high-performing colors in annual phlox – Blue, White, Magenta, Hot Pink, Peach and Pink. In the 2011 summer field trials, ‘Astoria Peach’ was named an Outstanding Plant at Colorado State University and ‘Astoria White’ was named the best phlox at Penn State University. Astorias are ideal for patio containers, window boxes, hanging baskets, garden borders and landscapes. Plants bloom early and continuously all season long. Astorias have an upright, mounding habit, reaching a height of 14 to 24 inches with a spread
of up to 30 inches. Mix the colors for a beautiful landscape effect.
General Culture
Use a well-drained peat/perlite mix and keep pH between 6.0 and 6.5. Use a constant feed of 200-300 ppm water-soluble fertilizer. Additional micronutrients are recommended. Keep temperatures at 72-80˚F during the day and 55-65˚F at night. Provide high to moderate light levels.
Plant Growth Regulators
A combination of Cycocel and B9 drench works well, using 2,000 ppm B9 and 1,000-1,500 ppm Cycocel.
Crop Timing
• 4-inch pots – four to six weeks with one liner and one or two pinches
• 6-inch pots – seven to nine weeks with two liners and two to three pinches
• 10-inch baskets – 12-16 weeks with three liners and three pinches
Pests & Diseases
onitor for whiteflies, aphids and mites. A broad spectrum fungicide drench is recommended after planting.
Helpful Hints from Aaron McDonald
Botany Lane Greenhouse, Lafayette, Colorado
The Astoria phlox are uniform across the six colors in the series, which is what Suntory strives for in all of its new breeding. The key to being successful with Astoria is growing them drier and cooler. It is also important to provide good air movement to help them dry out. You can grow them next to other crops, but need to remember to not treat them like a Surfinia or Million Bells. The hardest thing is telling the person who is watering not to water, because the phlox need drier conditions. Once established, the plants can take more water. It’s the first four or five weeks that it is essential to keep them drier, from liner stage to transplanting into a 4-inch pot. You have to really watch what you’re doing because they have a finer root system.
Later, the plants can take the summer heat all season. The Astorias were among the top performers at the Colorado State University trials even with the heat and rain we had. The Astorias are great in larger containers – 10-inch planters and 12-inch baskets. Putting five plants into 15-inch containers makes a nice, big show. I wouldn’t go directly from a liner to anything larger than a 4-inch pot. Too much soil will make it hard to establish.
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