What is the best temperature for cress to grow at?

They should be germinated for around two to three weeks in light at a temperature of 18 to 20 degrees Celsius. Young seedlings of Purple rock cress can be easily damaged by water it is therefore essential that they are only watered from below. The seedlings of Aubrieta should be planted out in spring in a sunny rockery with a spacing of about 30cm; soil should be well drained and have a pH of around 6 to 7.5.