As a rule, the best time to water your outdoor plants is early in the morning. The weather in the morning is cooler and this temperature will allow the water to be absorbed into the soil and hydrate the plants.
It’s not a good idea to water plants in the
afternoon or early evening because it its hot outside the water will evaporate
instead of being absorbed by the plant’s roots. However, tomatoes grown in containers will
need to be watered more than plants grown in the ground. It’s smart to check your tomato containers a
few times daily to make sure that the soil is not dry. If plants need to be
watered late in the day they water them, but at the soil line and not on the
leaves.
I grow tomatoes in containers and find
that the soil does dry out very quickly during the hot summer months. The container plants need regular watering. You do not want the soil to dry out, so I
recommend watering directly to the soil surface until the water drains from the
holes at bottom of the pot. Then check
your tomato plants again before the heat of the day. Water your tomato
containers deeply.
Tomatoes like it hot but extreme heatwaves might be too harsh for a tomato grown in a container. That is why my tomatoes get 6 hours of morning sun, and shade in the afternoon when the heat is excessive. Then from five in the afternoon to dusk the plants will get three more hours of late in the day sun.
Keep your tomatoes in container hydrated. Know that if you water your tomato plants in the morning, then skip the late in the day or early evening watering. The soil will dry out you will run the risk of your tomatoes cracking from receiving too much water after a dry spell.
Other Information
If you have not added mulch to your
tomato containers then I recommend that you do as it will aid in keeping roots
cooler and the mulch will hold moisture.