How hot is it where you are? And have you tried to use a moisture meter to determine how dry your soil is when this happens?

My experience with bamboo leaves curling is that they do this to conserve water when the plant is getting dry. When I have full, bright sun and temps in the eighties, I don't see leaf curling if the plant has enough water.

One other thought is that, if the plants you just planted did not have very large root balls, the root systems may not have enough capacity to provide all the water needed. This could happen if the plants you put in were just divided (taken out of the ground), had marginal-size root balls, and had not been allowed to stabilize in pots and re-build their roots for a number of months first. Do you know if your plants had been in pots for a while?

Some of them were freshly dug up clumps.... The landscaper checks on them periodically ... He explained same as you... That the ground may be damp but the roots are not sufficient just yet to absorb all the moisture required by the plant.....

Out of 175 ft of bamboo..most are doing fine with one deep watering in the am..there are two or three clumps that require additional watering throughout the day...But seems they are going later into the day before he leaves start to curl...Temps have been Mid to low 90 in direct sun..

If you live in a temperate zone, this problem will diminish as the season gets cooler. You may still lose a clump or two, but most of them should be fine in several months.

Thank you Kudzu9... I appreciate the help..