Have you tested your soil pH? Blueberries often won't grow well except in very acidic soil. Sulphur can help at the margin but it won't turn a fully alkaline soil acidic. They also prefer good drainage, which it sounds like you may not have. Adding organic material to the planting hole can make drainage issues worse because the good drainage in the hole simply becomes an underground puddle when the water reaches the un-amended soil below. It's better to cover the soil with organic material and allow it to incorporate naturally (or you can do light tillage to work it in at the beginning, but this doesn't work well after things have been planted. It also damages the existing soil structure). I would add some compost over the whole planting area, then a thick layer of wood chips (at least 4 inches deep, but less at the base of the plants) to help keep the soil moist and cool. Also, remove those weeds since they are competing with your plants.
The other plants should be OK as long as they have enough moisture and drainage. It's possible you aren't watering enough as the soil looks fairly dry to me. You said you water once per week--how much volume? Newly planted things generally need more consistent moisture until the roots establish. It won't matter if the deep soil is moist if the roots can't reach there yet. Alternatively, it's possible if you live in a wet climate and have poor drainage that once a week is too much. You want the soil around the roots to be moist but not soggy or drippy for more than a short period.
The first thing I always tell people when troubleshooting is the probe into the soil and get a sense of how wet or dry it is. Almost all plants prefer moist soil--not too wet, not too dry. Often too much moisture and not enough can cause similar symptoms, so it's important to get a sense of what's happening below ground before you change your watering strategy.