Water a newly planted blue star juniper regularly for the first year after planting. Typically, watering them once a week will suffice. Water them deeply with 1 inch of water rather than shallowly to help your blue star juniper develop deep and strong root systems.
Water an established blue star juniper once every few weeks. Water them more often when your area is experiencing drought conditions. An established juniper that was watered well the first year should be able to tolerate dry soil conditions.
Fertilize a blue star juniper in the spring just as you see new growth begin to sprout. Use an all purpose fertilizer, following the directions on the label. Water in the fertilizer with an inch of water after the application.
Avoid pruning a blue star juniper severely. Only trim off branches that are damaged, diseased or unruly.