|my backyard is sunny throughout the entire day and the plants i buy for my planters seem to dry out and die very quickly even though i water them each day. which annual plants are the best for this area and can withstand this direct sunlight.|
|Some annuals for a hot sunny location like this might include tropicals such as lantana, hibiscus, mandevilla, and thunbergia. Typical annuals that can also handle this include salvia, petunia and marigolds. Adding a trailing plant to shade the south and west side of the container is a good idea.
For the best results, make sure you are using larger planters so the roots are not crowded and so there is ample soil volume to insulate the roots from the heat of the sun; larger volume also holds moisture better. Use a good quality potting mix and consider adding the water holding polymer to it. Raise the pots up off the pavement or deck so air can circulate beneath them, this helps keep the roots cooler.
Finally, water slowly but thoroughly (in the morning if possible) so plants go into the hot part of the day fully hydrated. They may droop a bit toward the end of the day due to heat rather than to being dry, so check the soil before watering -- but if they are wilted in the morning then you have left it too long.