When creating a hedge, shrubs typically are planted in single rows, although a zigzag planting will increase the thickness.
Generally, only one type of shrub is used, but mixing several different types of compatible plants can be effective, especially when creating a large screen or sound barrier.
Typically, spacing is closer than we might plant shrubs for other landscaping purposes. The closer spacing, within reason, helps provide quicker results. A spacing of 3 to 5 feet is fairly typical, but small hedges, like a clipped boxwood or a dwarf yaupon hedge 2 feet tall, might be spaced less than 2 feet. And exceptionally wide-growing shrubs, such as Russian olives that may grow to be 10 feet across, can be spaced farther apart.
Plant the shrubs in well-prepared soil to help them grow as fast as possible. First, get rid of any unwanted vegetation, then till the soil in a strip about 2 feet wide (depending on the situation) and the length of the area where they will be planted. Next, spread a 2- to 4-inch layer of organic matter (compost, processed or aged manure, peat moss) over the area and till that in thoroughly.
When planting the shrubs, make sure that you do not plant them too deeply. The top of the root ball should be level with or slightly above the soil of the bed. Finally, mulch the planting and water it thoroughly to settle the soil.