The short answer is no. If you keep our fabrics clean, they will not mildew. Because acrylic fibres resist mildew better than natural fibres, this is one of the characteristics that makes us prefer to use them in our high-performance fabrics.
Mildew can grow on any dirty surface; to keep your fabric from mildewing, you must keep it clean. Mildew problems are further compounded by an accumulation of dirt or other particles on your material which serve as a food source for mould spores, thus accelerating their growth cycle.