Tree Health

At Redwood Tree Services® Ltd we assess a tree holistically. We look at the location of the tree as well as the roots, canopy and trunk, any mechanical defects in the tree structure or fungal bodies present to assess the overall health of a tree.

Oak Processionary Moth (OPM)

This invasive and dangerous caterpillar has spread across the South East of England and is now endemic across much of Surrey. We strongly recommend regular checks of all oak trees in the spring and summer months. The caterpillar of this moth will strip an oak tree of leaves and shed tiny hairs that are harmful to humans and pets. 

Do not allow anyone close to a tree with an OPM infestation and never touch the caterpillars or attempt to remove them yourself, as a defence mechanism the caterpillar’s will discharge their hairs if you go near them.  Even a slight exposure to the caterpillars can cause skin irritation and breathing difficulties.

We have developed the only portable, dual-chamber incinerator in the area designed specifically to deal with Oak Processionary Moth as laid out by Forestry Commission Protocols. We also have full protective clothing and rigorous safety protocols in place to ensure we can remove the caterpillar infestations for you quickly and safely.

Bite Injection

In some cases disease or environmental conditions can cause stress or damage to a tree and action needs to be taken to improve the health of the tree.

An experienced arborist will assess your tree and can offer the following treatments as required.

Bite Injection

This is used to inject nutrients into the main stem of a tree to improve the condition. This can be beneficial to trees that are showing signs of stress, helping to boost nutrients within the tree's system.


This is a very useful, naturally occurring ‘friendly fungus’. We supply and use Trichoderma to fight harmful decay pathogens. It is important to understand that decay pathogens attacking trees cause long term damage over periods of time. If a decay pathogen is treated with Trichoderma it can effectively stop the decay pathogen from spreading and causing further damage. Trichoderma is not a miracle cure and will not repair damage already done, but it is critical to catch the decay pathogen in the early stages of development.

We would always advise a visual tree assessment and either resistograph or picus testing to determine the extent of the decay prior to any treatment occurring to enable us to determine how far the decay has progressed. If the decay pathogen has been caught early and subsequently treated, the tree, being a dynamic structure, should produce reactive growth to strengthen areas that have been decayed.

We also use Trichoderma when planting new trees. This not only helps quick establishment, but also helps to improve resistance to drought stress.

Cable Bracing

A dynamic brace can be installed to reduce crown movement. We will advise when this is necessary for safety reasons. If you are having to cable brace a tree, you're already acknowledging that there is an intrinsic fault with the structure of the tree. Cable bracing is only a temporary expedient to prolong the tree's life by a few years. Regular maintenance of the cable brace is essential otherwise it can go on to damage the tree if not correctly maintained. This check should usually be done yearly by a competent arborist. Cable bracing is a cheap solution to maintaining your tree and mitigating a structural failure.

Air Spading

Ground compaction is a problem for trees in a lot of locations due to vehicles or pedestrians passing across the root plate. We use air spading to inject air into the root plate area and reduce the compaction. This can reduce stress and improve the health of the tree. Air spading can also be used to install cables around the roots of a tree for service companies and construction.

Air Spading is a useful tool to allow small fibrous roots of a tree to be able to penetrate compacted ground, with the addition of mulch this enables water retention which will then provide excellent biological activity in the soil and also improve soil topography for the tree roots to thrive.

Ground Mulching

We can supply and complete mulching around trees to reduce competition from vegetation such as grasses and to improve soil topography. We are investing in the technology to produce our own, specialist tree mulch which we can also supply wholesale as required.