Keep in mind when planting that Cascading Chinese Lanterns is thought of as very hardy, so this plant will survive though longer winters with little or no damage. Ensure your soil is loamy and has a ph of between 6.0 and 7.0 as Snapdragon is a weakly acidic soil to neutral soil loving plant.
By our calculations, you should look at sowing Cascading Chinese Lanterns about 56 days before your last frost date.
Ensure that temperatures are mild and all chance of frost has passed before planting out, as Cascading Chinese Lanterns is a very hardy plant.