The common hawthorn, or Crataegus monogyna is a shrub native to the UK that makes formal 1.5 to 3 m (5 to 10 foot) tall hedges. The shrubs or trees produce tiny, deep green, glossy foliage and fragrant white or pink blooms in the spring. During autumn and winter, the plants produce deep red berries known as haws that attract birds to the garden. Create a hawthorn hedge by planting the trees or shrubs in a single row along your property. The thorny hedges form natural boundary walls that increase privacy and protection.
Locate the planting site in your garden or yard where you want the natural privacy screen or barrier. Ensure the site has well-draining soil and receives full sunlight to partial shade. Measure the length of the area to determine how many hawthorn shrubs you need. Space hawthorn plants 30 to 45 cm (12 to 18 inches) apart along a row.
Remove stones, weeds and other plants from the desired planting site by hand or with a weed killer. Spread a trail of powdered chalk along the site if you want to create a formal hedge. Mark the exact location for each hawthorn plant over the chalk line, spacing each 30 to 45 cm (12 to 18 inches) apart.
Dig a planting hole as deep as the root ball of each hawthorn plant but two times as wide, directly on the chalk mark along the marked line. Lower each plant in the hole so it rests at the same depth as its nursery container.
Backfill each hole with soil and tamp it with your hands to remove trapped air. Ensure the soil around each planting hole is level with the surrounding ground.
Water the soil around each plant until it's soaked 20 to 25 cm (8 to 10 inches) deep. Use drip irrigation or a soaker hose, which encourages deeper roots and does not wet foliage.
Cut back 1- to 2-year-old hawthorn plants down to 15 to 20 cm (6 to 8 inches) tall using sharp, sterilised pruning scissors. Cut each stem diagonally, directly above each bud that faces outwards, to encourage the base of the hawthorn hedge to grow thick and full. For older hawthorn plants, cut each branch down to one-third of its height.
Prune the hawthorn hedge two times a year, preferably in early summer and then in autumn. Use hedge cutters to remove old, dead or diseased branches and trim the hedge down to your desired size and shape. Also thin out branches in the plant's interior to improve sunlight penetration.
Plant the hawthorn shrubs between October and March, when they are dormant. Wear gardening gloves, a long-sleeved shirt and long trousers when planting or trimming the hawthorn plant to prevent direct contact with its thorns. If planting a formal hedge, prune it so its base is wider than its top. Trim every 30 cm (12 inch) new growth down to half its length until the formal hedge reaches your desired thickness and height.