Q.Bamboo shoots died
After rainy springs our bamboo typically sprouts new shoots up to 1 1/2 inches in diameter and they grow well, but this year the new shoots turned black and died. Do you know what would cause this?
Press the soil at the base of the bamboo with your hands to see if it is damp. The dirt should be damp to the touch, but not pool with water when you press into it with your hand. If you dig down, the soil needs to be damp down to 6 to 8 inches. Like any other plant, bamboo can die from both over-watering and under-watering.
Remove dying stalks so the others do not have to fight for energy that is being supplied to a sick sections.
When you see growth you can apply a nitrogen-rich fertilizer in the early spring to provide nutrients through the growing season. Because it is a grass, using an organic fertilizer made for grasses works best. Make a second fertilizer application in late spring to last the remainder of the year.
https://www.gardeningknowhow.com/ornamental/foliage/bamboo/caring-for-bamboo-plants-in-your-garden.htm
