How to plant a hedge and how long they take to grow

Although autumn is on its way, there are still plants and trees that can start to grow in cooler months and if you’d like to grow a hedge, there’s no time like the present.

The Royal Horticulture Society has shared guides on how to plant and grow hedges so if you’re a beginner when it comes to hedges, this might help you get started.

How to plant hedges in your garden

Prepare the soil

The Royal Horticulture Society says that planting a hedge is similar to planting any tree or shrub but soil preparation is key.

The Royal Horticulture Society recommends preparing the soil before planting a hedge (Image: Canva)

To prepare the soil, you should dig over a strip 60-90cm (2-3ft) wide and one spit or spade blade deep.

Remove all the weeds, unless a weed killer has been used before you dug into the ground.

The Royal Horticulture Society website adds: “Soils that become waterlogged in winter may require a permanent drainage system. Alternatively, form the soil into a ridge about 15-20cm (6-8in) high and 50-70cm (20-28in) across to plant into”.

Avoid adding organic matter to the bottom of the trench because it decomposes and can make the shrub sink.

Plant the hedge

Position a boundary hedge 90cm/3ft away from the boundary line to allow the hedge to fill out before it becomes a problem with overhanging a pavement or a neighbour’s property.

Planting distances vary within the row from 30-60cm (1-2ft) – it depends on the plants’ final size, the size of hedge required and plant vigour.

For hedges thicker than 90cm (3ft), plant a staggered double row 45cm (18in) apart with plants 90cm (3ft) apart.

The Royal Horticulture Society says that hedges can take three to seven years to reach their desired size (Image: Getty Images)

You’ll need to trim damaged roots back to healthy growth using a sharp knife or old pair of secateurs, The Royal Horticulture Society advises.

Next, you’ll need to spread out the roots and make sure the planting depth is how it should be – the part where the roots come out of the stem should be level to the surrounding soil.

Container-grown plants will need the compost scraping away from the top of the root ball to reveal this part.

If you’re planting a hedge with sandy or heavy clay soils, you’ll need to “mix organic matter, such as garden compost or a proprietary tree and shrub planting mix, with the soil dug out from the hole to backfill. Alternatively, spread over the soil surface and mix into the top 25cm (10in) of soil with a fork (forking in)”, The Royal Horticulture Society explains.

Next, work the soil between the roots and firm the plants in to make sure the soil is in close contact with the roots. If the soil is dry, you’ll need to water it.

Then, mulch to 7.5cm/3 inches deep after your hedge is planted to keep weeds away.

How long do hedges take to grow?

In the first two years of planting a hedge, you’ll need to water it well during dry spells.

After the first couple of years, a hedge shouldn't need watering.

Make sure that the hedge and 45cm/18 inches on each side are weed free and top dress the hedge “annually with a general-purpose fertiliser, such as Growmore at 70g per sq m (2oz per sq yd), and re-apply mulch as required”.

The Royal Horticulture Society says that hedges can take three to seven years to reach their desired size.

If your hedge is in an exposed place, it might need shelter in its initial years of growing.

Semi-mature hedges provide an instant hedge but can be more expensive and need extra care when it comes to planting and watering.