HOA ociation sent me a hearing notice for bare patches in our yard. Can they do that without prior notices?

This is a house in Charlotte,NC and belongs to the Withers Grove subdivision. We did not receive notices of violations prior to being asked to attend a hearing. We have been working with our property manager to get the yard looking nice etc and have contracted with a company to take care of it on our own and even before the hearing notice. The HOA is threatening that they will fine us $100 a day about 5 days after the hearing if we fail to do as they tell us. I am very frustrated as we are doing our best to improve the lawn and the HOA doesn't seem to give time for the full effect of the treatment to kick in. Our landscaper that we contracted recently has not been able to seed or sod the 2 bare patches because of the rain being experienced the past few days. Don't we, as homeowners, have rights?