should be install 4-5” inches thick except right at the plant. There you would go up to the plant and may only have 2” thick.
So as not to disturb the root system it is best to use a heavy duty landscape fabric.
Fabric will let water through and reduce weed growth. Note: After installing all mulches, be sure to water well.You should try to simulate having 1” of rain but not directly on the plants when the heat is above 20 degree Celsius, then water the next day to keep the moisture level in the soil at the right level.
For watering after that, you should have a proper watering schedule set out by your landscaping contractor.