Glenmore Guide: How to Plant a Hedge

Need to knows:

  • Choose whips that are at least 60cm tall
  • Plant 3 whips per metre to achieve a thick hedge quickly
  • You can grow a hedge up to 2m high without permission
  • Trim the tops and sides a few times a year
  • Native hedging helps to attract wildlife
  • Plant evergreens and semi-evergreens from September to mid-October
  • Plant deciduous hedging plants from late October to early March
  • Water new hedges well for the first two years
  • Do not plant hedges while soil is frozen or waterlogged

How do I choose my hedging plants?

There’s a surprisingly wide range of options when it comes to hedging plants, because most trees and shrubs can be planted and pruned to create a hedge. It all depends on the type of hedge you want, when you’re hoping to plant, and how much maintenance you are able to do. Your budget and timescale will also inform your decision.

Hedges are grown for a variety of reasons, but usually they mark off boundaries. If you have a smaller outdoor space, or want a border boundary, you may need a low-growing variety, whereas if privacy or weather protection is the priority, a dense, tall hedge is called for.

You’ll also need to consider the style of your outdoor space. If you’re cultivating a cottage garden effect, informal or flowering hedging might be the best options. On the other hand, if you’re going for a stylish urban garden with hardscaped areas enhanced with ornamentals, a more formal hedge – perhaps with the option of topiary – may be in order.

Think carefully about your requirements for your hedge – and the conditions you will be planting into. You need plants that can tolerate your soil, levels of shelter, sun and shade. Look into the growth rates and pruning needs of the plants you choose so that you are sure it will create the effect you desire – and that you will be able to manage it.

Which hedging plants should I choose?

Hedging plants can be categorised in many ways. One of the key differentials is whether they are evergreen or deciduous. Evergreen hedges will provide shelter all year round, but the swing side of that is additional maintenance.

Deciduous hedges will either lose their leaves over winter, or display crispy, brown leaves (in the case of beech, this creates a very pretty effect). They are more forgiving if you lapse on the pruning – and are more easily restored. Although there is less privacy in the winter months, deciduous hedges help to filter strong seasonal winds. Turbulence can be created when a dense evergreen hedge meets mighty winter gusts!

If you are looking for a formal hedge, Buxus Sempervirens (box) and Fagus Sylvatica (beech) are popular choices. Conifers like yew (Taxus Baccata) and Leylandii also work well, but often grow quickly and require more maintenance.

Viburnum is a good option for informal hedging due to its colourful foliage, while Griselinia littoralis is a low-maintenance, flexible hedging plant that copes well with most weather conditions and can be utilised in either a formal or informal capacity. Griselinia is a popular choice for coastal gardens – another option for seaside gardens is Rosa rugosa.

For a low-growing hedge, lavender (Lavandula angustifolia) is a fantastic choice, offering beautiful colour and scent. At the opposite end of the scale, Portuguese laurel (Prunus lusitanica) is a wonderful large-growing evergreen hedge.

If you want to provide habitats and sustenance for wildlife, native hedging plants are your best bet. A good choice is hornbeam (Carpinus betulus), but a mixed hedge including beech, field maple, holly and blackthorn is even better – particularly when rambling plants like honeysuckle, ivy, bramble and wild rose are allowed to grow through the hedge.

What size plants are best?

The most economic way to buy hedging plants is bare-root ‘whips’ of around 60cm (2ft) in bulk. Rather counter-intuitively, these smaller plants can actually establish more quickly than more mature plants, which often suffer from transplant problems and require greater care for longer.

You can also buy root-ball or container grown hedging plants, which are dearer.

If you want to create a hedge particularly quickly, and don’t want to wait for whips to mature, you will need to buy ‘instant’ hedging – these are semi-mature plants that are more expensive than whips, and will need careful attention and watering for at least two years after planting.

When should I plant my hedge?

Whatever time of year you choose for planting, first make sure the soil is not frozen or waterlogged – hedging plants will struggle to thrive in these conditions. If you do have to delay, keep the plants in a frost-free shed and protect their roots with moist compost, straw or paper covering in plastic sheeting, to prevent them drying out.

For evergreens, conifers and semi-evergreens (such as privet hedging), early autumn is the prime time to get planting. However, you can plant them all the way up to late winter.

Deciduous hedging is better planted from mid-autumn to late winter – any time after leaves have fallen from the plants.

How do I prepare the ground for a hedge?

It is important to prepare the soil carefully before planting. Dig over the length of the hedge you want to a depth of your spade blade (this is known as a ‘spit’), creating a strip between 60cm and 90cm wide (or 2-3 ft). Remove any weeds (if you haven’t previously treated the area with weed killer). If your soil is prone to water-logging, you’ll need to consider adding a drainage solution.

How far apart should I plant hedging whips?

Firstly, decide where the hedge will be. Boundary hedges should be set back around 90cm (3ft) from the boundary line, giving it space to fill out without immediately infringing on your neighbour’s property or public walkways.

Choosing the planting density (the distance between plants) depends on the final size of the plant species, the height and density of hedge you want, and growth rate. A good rule of thumb to grow a thick hedge relatively quickly is three whips per metre. If you’re aiming for a hedge thicker than 90cm (3ft), we would recommend planting a staggered double row 45cm (18in) apart, with plants 90cm (3ft) apart.

How do I plant my hedging whips?

Now you need to prepare the plants themselves. First, trim any damaged roots back to the healthy growth. You can do this with secateurs or a sharp knife. Then, separate the roots and make sure you can see the point at which they spread away from the stem (for container grown plants, you may need to scrape away some compost until this is visible). This point should be planted level with the surrounding soil.

Once the plants are at the right depth, fill in the soil, working it well between the roots, and firming it down. Water the planting area (particularly well if the soil is dry), and add mulch to a depth of 7.5cm (3in). This will help to prevent weeds while the plants develop and establish. 

If your soil is sand or clay based, you’ll need to combine some garden compost with the soil when you backfill.

How do I care for my hedging plants?

The main thing to prioritise is watering. Even if it rains, make time to water your newly planted hedge regularly – particularly if you used semi-mature plants. They will need top-ups during dry spells for the next two years!

Most hedges will need at least an annual trim to maintain the desired shape, size and condition (for evergreens it may well be more). Another annual job is to add a general-purpose fertiliser and mulch. You’ll also want to maintain a weed-free area 45cm (18in) either side of your hedge – weeding will need to be more regular during the summer months.

Need more help?

For more detailed information about the individual planting densities/distances and maintenance requirements of specific varieties, the RHS provides excellent advice. They also provide examples of hedging plants for specialist purposes (such as thorny plants for security or narrow hedges for small spaces) or conditions (hedges that will grow in wet or clay soils, or in particularly cold climates, for example).

Alternatively, for personalised advice, get in touch with the Glenmore team who will be delighted to share their expertise and help you choose and grow your perfect hedge.