Water, water every.. where??
Planting out in the warmer summer months is absolutely fine, but the one thing you must make sure of is watering well after planting. Roots need to establish in to the surrounding soil for a plant to become self sufficient, and this can take upwards of several weeks, until that point the plants are reliant on you for a regular drink.
For potted plants watering is an ongoing requirement, and it’s especially important through the summer months. A well draining pot will not hold on to any moisture for more than a day or two so make sure you keep those pots topped up.