Guidance

Replace trees after felling due to pests and diseases

Find out how to restock trees on a site where they have been felled due to pests or disease.

From:
Department for Environment, Food & Rural Affairs and Forestry Commission
Published
31 August 2021

Restocking trees after felling

When restocking a site with trees, you must not plant the same species that was affected by pests and diseases.

Before you start to restock, you need to get these permissions if they are relevant to your site:

You should choose replacement species that are:

  • known to be suitable for the land you’re planting
  • more able to withstand disease, pests and climate change

All proposals must comply with the UK Forestry Standard.

Depending on your situation, you may need to:

Benefits of restocking a site with more resilient tree species

Restocking a site with trees that might be more able to withstand pests, disease and climate change can:

  • reduce the risk of further pests and disease outbreaks
  • improve the health and biodiversity of the site
  • increase the site’s genetic and species diversity for resilience
  • increase the site’s productivity, for example if you grow trees for timber
  • save you money in future maintenance costs

When to restock by planting

You may restock a site by planting trees, unless you are restocking a site of special scientific interest (SSSI) affected by ash dieback. In these sites you should restock by natural regeneration where possible.

If you plant trees you can plan what your site will look like in the future. You’ll know what trees you’ll have on your site, and how many.

How to source trees to plant

The trees you plant must be free from pests and diseases.

You should:

  • get your plants from nurseries with clear plant health management standards in place – find a nursery with Plant Healthy certification
  • get in touch with tree nurseries as soon as you decide what to plant, to check they will have the trees you need when you need them

If you’re planting trees you should source trees grown in the United Kingdom from a Forest Reproductive Material Certified supplier.

When to restock by natural regeneration

On some sites, particularly those affected by ash dieback or on sites of special scientific interest (SSSIs), it may be appropriate to use natural regeneration. The Forestry Commission can advise whether it is a suitable approach.

Restocking by natural regeneration is not supported by the tree health pilot.

Choosing replacement tree species

You must not plant the same species that was affected by pests and diseases.

The tree species you should choose depends on the type of site, your management objectives and the species of the trees you remove or the disease that’s affected them.

If you want to plant trees you should:

To get advice from an officer for the tree health pilot scheme, contact thpilotenquiries@forestrycommission.gov.uk.

Read more about species and provenance choice for adapting England’s woodlands from Forest Research, the research agency of the Forestry Commission.

Replacing trees in field boundaries

To establish new trees in field boundaries, you can:

  • select either existing saplings or coppice regrowth to become mature trees
  • plant new trees, as many boundaries will not contain suitable tree saplings

In both cases you should:

  • plant or select native tree species found in local boundaries, such as oak, beech, field maple, hawthorn or willows
  • plant or select a mix of different species to support a wider variety of wildlife
  • avoid planting ash because of ash dieback disease
  • use other species alongside any ash saplings, as these may well die from disease
  • immediately protect trees from browsing and grazing animals, using appropriate tree guards or fencing
  • label the trees with brightly coloured tags, so anyone trimming or flailing knows that there are protected trees within the boundary

When selecting existing saplings, choose undamaged stems that are growing straight up all the way from the base. These should produce a good, strong trunk. If you lay or coppice a hedge, you can select strong new growth to become trees.

Restocking trees in a site of special scientific interest (SSSI) and ancient woodland sites

Sites that were once ancient woodland but have been converted to planted forests are known as plantations on ancient woodland sites (PAWS).

Many PAWS retain at least some characteristics or remnants of native woodland flora, which give them the potential to be restored to native woodland.

Ancient semi-natural woodland (ASNW) features of interest are mainly tree, shrub, plant or soil-based, such as fungi. Other characteristic features or remnants might include:

  • uncommon tree or understorey species (for example, Midland hawthorn, wild service tree, small leaved lime)
  • large coppice stools
  • archaeological features (for example, woodbanks and sawpits)
  • deadwood hulks
  • veteran trees

You must:

  • make sure these remnants are protected
  • restock native species or naturalised species

At the discretion of the Forestry Commission, conifers can make up to 20% of the restocking mixture if you can show that there will be no negative impact on surviving ancient woodland features.

Trees should be planted so that you will have a mainly broadleaved stand if you do not manage the site. This is known as a fail-safe mixture.

You can achieve a fail-safe mixture by planting conifers either singly or in groups of 3 to 5 trees, scattered throughout the mainly broadleaved area. Line mixtures (alternate single species rows of conifer and native broadleaves) are not acceptable as a fail-safe mixture.

You can find out more about restocking ancient woodland sites – both ASNW and PAWS.

For SSSIs, the same advice applies but you may need to apply for consent from Natural England for work on or near an SSSI.

It’s good practice to mix replacement species where possible, to build resilience into the site. You should avoid a single species taking more than two thirds of the tree canopy.

Get more information on managing ancient and native woodland sites.

Tree species you can use to restock diseased sites

You should make sure the species you use for restocking are suitable.

Phytophthora ramorum

You must not plant any of the following species:

  • larch or sweet chestnut trees if you’ve removed these species because they had Phytopthera ramorum (as the spores for this disease can stay in the soil for several years) – this includes European larch (Larix decidua), Japanese larch (Larix kaempferi) and hybrid larch (Larix hybrid)
  • rhododendron

The following species can become infected if there are enough spores on the site and should only be planted if there’s a low level of previous local infection:

  • beech (Fagus sylvatica, Nothofagus obliqua and Nothofagus procera)
  • holm oak (Quercus ilex)
  • white willow
  • Douglas fir (Pseudotsuga mensiezii)
  • western hemlock (Tsuga heterophylla)
  • grand fir (Abies grandis)
  • turkey oak (Quercus cerris)
  • sessile oak (Quercus petraea)

These tree and shrub species have shown themselves to be resistant to ramorum disease:

  • Lawson’s cypress (Chamaecyparis lawsoniana)
  • Norway or European spruce (Picea abies)
  • Sitka spruce (Picea sitchensis)
  • Scots pine (Pinus sylvestris)
  • lodgepole pine (Pinus contorta)
  • Corsican pine (Pinus nigra var larici)
  • English yew (Taxus baccata)
  • western red cedar (Thuja plicata)
  • field maple (Acer campestre)
  • sycamore maple (Acer pseudoplatanus)
  • horse chestnut (Aesculus hippocastanum)
  • alder (Alnus glutinosa)
  • silver birch (Betula pendula)
  • downy birch (Betula pubescens)
  • European hornbeam (Carpinus betulus)
  • common hazel (Corylus avellana)
  • common holly (Ilex aquifolium)
  • wild or bird cherry (Prunus avium)
  • English oak (Quercus robur)
  • white willow (Salix alba)
  • goat willow (Salix caprea)
  • small-leaved lime (Tilia cordata)

Find more advice about restocking sites affected by Phytophthora ramorum

Ash dieback

You should plant native trees that support ash wildlife and usually grow in the same conditions.

Any trees that naturally regenerate including ash could be part of your woodland structure. You should monitor them for signs of disease.

Read more about dealing with ash dieback on SSSIs.

Sweet chestnut blight

You must not plant any chestnut (Castanea) species when restocking.

Other tree species at risk of sweet chestnut blight include:

  • oaks (Quercus)
  • maple (Acer)
  • sumac (Rhus)
  • hickory (Carya)
  • chinquapins (Castanopsis)

They can become infected from nearby diseased chestnut trees. Only plant these species once the risk of infection has gone.

Spruce bark beetle

You must not plant any spruce species, including Norway spruce.

If your site is in south-east England, you may plant pine species with care and only after any risk from a local outbreak has passed.

Preparing the site for replanting

You’ll need to get permission to replant a site if the area includes:

If you’ve felled trees under a statutory plant health notice (SPHN), you’ll need to continue to comply with the actions on the notice if you plant any new trees.

Controlling regrowth of disease affected species

You should use a clearing saw or spot applications of herbicide to control regrowth. You can also use this method to control colonisation by disease susceptible species except ash on ash dieback sites.

You should only use mechanical swiping where the vast majority of the regrowth has to be removed.

Boom or overall applications of herbicide should not be used on ancient or native woodland sites.

Other regrowth

Other species can be allowed to regenerate, even if these are eventually reduced in number or replaced once the site can be restocked. This can help to keep the site manageable, and will also help protect soils and give better continuity of woodland conditions.

When to plant new trees

Nurseries supply trees either bare-rooted or cell-grown. Nurseries grow bare-grown trees in prepared outdoor beds, and cell-grown trees in a compost plug or cell.

Bare-rooted stock is lifted from nursery beds for delivery between late autumn and early winter.

Plant bare-rooted trees between November and February, depending on weather conditions and location.

Ask your nursery for advice on the best time to plant cell-grown tree stock.

You should:

Monitoring newly planted trees

You must monitor the tree health of all the new trees you plant by checking regularly for signs of disease and report any that need to be notified by law – find out how to make a plan to reduce the risk of tree pests and diseases.

How to report pests and diseases

You must report any notifiable pest or diseases you find on TreeAlert.

How to maintain your restocked trees

Protect all trees from damage until they’re well established.

You can control competing vegetation by spot spraying with herbicide or cutting. Do not spot spray with herbicides next to watercourses.

Maintain all tree protection measures like individual spiral guards, shelters or fencing. Replace any that fail.

Replace any trees that fail within the first 5 years after planting. After 5 years, any replacement trees are more likely to be over-shaded.

Within 15 years of planting you should see:

  • healthy, vigorous growth of all trees
  • trees that form a closed canopy

Find out more about how to maintain newly-planted trees.

Published 31 August 2021
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