Plant them out the sooner the better now.
Give them plenty to drink (water) and keep watering they need to establish themselves.
Next year and then after, you probably wont need to water ever again but this year I would water them well and if it does not rain do it as often as daily.
If it is a dry year when you first plant the chances of loosing the plant are more likely due to lack of water then anything else.
As I say, after that, usually, they will look after themselves,