Water and fertilize regularly to keep up with the needs of actively growing plants.
If a plant regularly wilts in the afternoon but the container always seems to have enough moisture in it move the container so it is protected from the late afternoon sun. Remember plants may also wilt if the soil is kept constantly saturated and the roots are starting to rot, in which case allow the soil to dry out before watering again.
It can be misleading to judge the soil surface for water content in the container. Instead, lift the container (it will be heavier when the soil is saturated); or stick your finger deep into the soil, if it feels cool there is probably enough water, if it feels closer to air temperature then it probably needs water.
Keep a vigilant eye out for insect pests starting to emerge from over wintering eggs, or aphids flying in and giving birth to copious numbers of live young. Three applications of insecticidal soap spray, applied at 7 day intervals, will quickly knock down these young insects before they have time to mature and lay more eggs.