These plants originate in New Zealand, and are well adapted to the European climate. These plants do not like direct sun, but prefer semi shaded locations, especially in the hottest periods of the day, so you can grow them in a shady flower bed, or keep them in pots and move them to the shade when the sun is hottest.
Watering should be regular, in order to keep the soil moist, but not soaked with water. Every 10-12 days provide fertilizer for flowering plants, throughout the year. Check your veronicas periodically to remove the spikes of withered flowers and any damaged leaves, to prevent them becoming vehicles for fungal diseases.