Keep in mind when planting that Chatsworth is thought of as tender, so remember to wait until your soil is warm and the night time temperature is well above freezing before moving outside.
Soil temperature should be kept higher than
68°C / 154°F to ensure good germination.
By our calculations, you should look at sowing Chatsworth about 77 days before your last frost date.
Ensure that temperatures are mild and all chance of frost has passed before planting out, as Chatsworth is a tender plant.