My husband works in landscaping n unless ut snows hard he has no hours. He asked his employer if he can apply for partial benefits n his employer told him no. How is this possible?? Should he go ahead n file regardless?

Anyone who is not working full time may file for benefits to receive a determination of eligiblity

Yes. His employer does not have the authority to deny someone benefits. He should apply and be certain to report any and all gross earnings each week. If the emploer offers to pay him cash that is not a good thing and he should seek out a new employer and report that to the unemployment compensation fraud department.