This is a complicated question. There are many types of fabrics, and they are made from a variety of natural materials (like animal coats, cocoons of silkworms, plant seeds, leaves, stems, etc), synthetic (or human-made) fibers (made of plastics, chemicals, or natural materials), and combinations of the two.

When you pour water on a fabric, it will not hurt it, but it may cause changes to the fabric properties. For example, when silk gets wet, it will shrink as it dries. When you pour water on a fabric like cotton, the water molecules get inside the cotton fibers and inflate them (like when you add water to a dry sponge and it plumps up). For cotton, those water molecules will actually attach to the cotton fibers and make the fabric more resistant to breaking.

Other fabrics respond differently. And sometimes the fabric is treated with water resistant chemical coating so water will bead up and roll off the fabric (like when you pour water on a plate), but even that fabric will eventually become soaked if enough water is poured on it (or the fabric is put into a bucket of water).

All that said, traditional fabrics will not grow when water is added to it. However, there are new technologies in microbiology using microbes to create fabric-like materials by feeding them sugar and drying out the resulting substance. It is possible that adding sugar water to such a fabric, if the microbes were still present, could grow fabric.

By 'fabric,' do you mean cloth? You can pour water on cloth. Most cloth gets washed in the washing machine, with soap and water. Some cloth needs to be dry-cleaned, without water. Cloth doesn't grow when you pour water onto it.

Some fabrics are harmed by water, and some aren't. Most fabrics soak up water and will swell up when you pour water on them. I need to know what fabric you are using to answer your question.