Wash English cucumbers and let them dry. Place the cucumbers to the jar vertically. After placing the first row of cucumbers, put lemon slices and garlic cloves between the cucumbers and add the first portion of rock salt.

Continue steps until the jar is full of cucumbers and no space left at the top of the jar. (Letting minimum air gap at the top of the jar helps better fermentation).

Pour the juices of lemon to the jar. And then pour the Boiled cold water until to the top of jar. (The amount of the water depends on the size of your jar). 

Close the jar lid very well and let the jar wait 3 weeks at room temperature and shade. (During the waiting/fermentation period never open the lid).

After the 3 weeks, open the jar and serve.