Unfortunately, there are very few plantings where this is the case. Cool weather, especially cool nights, can delay and reduce runner production. You can't increase the temperature in your plantings, but you can make sure that adequate moisture and nitrogen are present. Also, some soils are so packed by rain that runners are having a hard time rooting. Cultivate and throw some loose soil onto the row to help these runners put down solid roots.
Powdery mildew is very evident in new planintgs where humidity is high.
As this disease infects leaves they curl upwards. The underside of the leaf, now exposed to the sun may develop a pinkish tinge. White powdery signs of this fungus do not always show up. Annapolis are especially susceptible, but other varieties mat also be affected. Don't worry about this disease in new plantings now.