Q.brown patches on my leyland cypress trees
I have a lot of leaves turning brown in patches. Help?

The browning patches that are in the image could simply be some winter damage, but could also be a more serious disease.
You will need to make further inspections of the branches and trunk of the tree to pinpoint the cause if it is a fungus or due to pests.
The links below will help you.
http://www.clemson.edu/extension/hgic/pests/plant_pests/trees/hgic2004.html
https://www.gardeningknowhow.com/ornamental/trees/leyland-cypress/growing-leyland-cypress-trees.htm
https://www.gardeningknowhow.com/ornamental/trees/cypress/cutting-back-cypress-trees.htm