Obtaining plants

Hedging plants are available from specialist suppliers.

It is possible to collect seeds and propagate your own plants, growing them on for two to three years in a nursery bed before they are planted out to form a hedge. Propagation and nursery care of native trees and shrubs is a project well suited to voluntary conservation groups and others, and is described in other publications. For details see Trees and Aftercare – Propagation and Our Trees (CVNI, 1996), the latter publication describing the propagation of trees native to Northern Ireland.

Size of plants

Hedging plants are available as seedlings, transplants, or in containers such as ‘Rootrainers’. Seedlings and transplants are sold as ‘bare-root’ plants in late autumn after leaf-fall, whereas plants in containers are normally evergreens such as holly and yew which do not survive as bare-root plants. Some nurserymen also supply deciduous species in Rootrainers (see below) for planting during the growing season.

Seedlings are plants which have been sown direct in the seed bed, and are grown on for one or two years before being lifted. Some species are undercut with a cutter bar or spade, to promote plenty of fibrous root growth which will aid final establishment. These are referred to as, for example, ‘1 u 1’, which means one year in the seed bed, then undercut and grown for another year in the same position.

Transplants are plants which have been transplanted in the nursery to promote fibrous root growth, and are sturdier and bushier, but more expensive than seedlings. They are referred to as, for example, ‘1 + 1’, which means one year in the seed bed, and then transplanted and grown on for another year.

Transplants for hedging should be ‘feathered’, that is well furnished with evenly balanced lateral shoots down to ground level, depending on the species. ‘Whips’ are transplants with a single main stem, without significant feather growth, suitable for planting out to form hedgerow trees.

Rootrainers are special containers, supplied in a hinged set or ‘book’, which can be opened up for minimal root disturbance at planting. Root growth can also be inspected without damaging the plant. The sides of the containers are ribbed to encourage downward root growth, and to resist the tendency for roots to spiral. The regular size of rootball makes planting easy, and plants have a good survival rate. Rootrainers are available in a range of sizes to suit different species and purposes.

Most nurserymen will offer plants in a selection of types and sizes, as listed below, with a discount for quantity. The size of the plant in relation to its age will depend on the species and on growing conditions in the nursery, including spacing, feeding and watering.

Slower growing species such as beech and hornbeam are more normally available as (1 + 2) 45-60 cm transplants.

Transplants (1+1) 45-60 cm are the usual choice for hedging. These should have sturdy root systems to establish quickly with minimal losses. Cheaper seedlings, either one or two year, can be used, but these will not have such good root systems, and losses may be higher. However, they can be quickly notch planted into suitable ground. Larger transplants 60-90cm can also be used. Whatever size is used, careful attention must be given to weed control for at least 2 years after planting.

Single or double row?

Hedges can be formed of a single row of plants, or a double staggered row. Occasionally, three row hedges may be planted.

Many of the hawthorn enclosure hedges were planted as a single row, and have proved their value over the centuries. However, hedge layers tend to prefer double row hedges, to provide adequate pleachers. Double row hedges are likely to be more stockproof and provide more shelter than a single row, although for an established hedge, the management regime is a more important factor than the original planting pattern. Wider hedges are of higher wildlife value because of the extra habitat they provide.

Spacing

The recommended spacing for both single and double row single species stockproof hedging are given in the table in table 5.2. Close spacing is needed for single row planting so that if any plants fail, adjacent plants will quickly grow to fill the gap. For hedges which are to be laid, the distance between the rows should be no more than 15” (40 cm). Typical spacing for hawthorn is shown in the diagram above.

For mixed hedges, a spacing of about 18” (45cm) can be used for single row planting.

Wildlife hedging mixes

Some nurseries supply mixtures of species for ‘wildlife’ or ‘conservation’ hedges. The mix will comprise about 50% hawthorn and blackthorn, with a selection of other species from the ‘wildlife’ hedge list (table 5.1), as chosen by the supplier.

The supplier will advise on the planting distance suitable for the mix, normally expressed as the number of plants required per length of hedge. For example 40 plants per 10 yards if planted in a double line, or 20 plants per 10 yards if planted in a single line, which is equivalent to an 18” (45cm) spacing in the row. A gap of about 3ft (1m) between plants in the row and between rows is suitable for an informal wildlife hedge which is not going to be laid.

When to order

Plants should be ordered in summer or early autumn, and will be lifted and despatched as soon as possible after leaf fall. The plants should arrive in good condition, carefully packed in plastic sacks in which they can be kept in the cool for a few days before planting. Contact the supplier if there is any problem with the packaging or the quality of the plants.

If planting is to be delayed, plunge or ‘heel’ the plants into the ground by digging a shallow trench as shown. Choose a sheltered spot in good garden soil that is moist but not waterlogged. Prepare the trench and have some fine soil ready to cover the roots before you open the packaging, so that the roots are exposed to the air for the absolute minimum time. Depending on how they are tied, keep the plants in loose bundles rather than separating them at this stage. Cover the roots carefully so that soil trickles down amongst the roots to keep them moist and protected from frost. Thoroughly water them in, and do not tread on the covered roots.

Planting season

Hedges are best planted in the autumn. Deciduous species such as hawthorn, blackthorn, beech and hornbeam should be planted as soon as possible after leaf-fall, in October or November. If necessary, planting can continue throughout the period of dormancy, until March, provided weather and ground conditions are suitable. Holly and other evergreens are best planted either in September, or in April or early May, to avoid the risk of frost.