When is the Best Time to Prune an Alder Tree?

Expert insight into the best time to prune an alder tree; why alder tree pruning is important, and how to identify common alder tree diseases.

The alder tree is a deciduous, conical shaped tree that is native to the UK. Of the Latin Alnus glutinosa and also known as the common alder, black alder and European alder, this tree can reach of heights of around 20 metres and will live up to 60 years.

The alder is known for its important symbiotic relationship with Franka alni, a bacterium found in the tree’s root nodules that absorbs nitrogen from the air and makes it available to the tree. In return, the tree feeds the bacterium with sugars via photosynthesis. As a result, the fertility of the soil where the tree grows gets a boost, and the species that follow get to enjoy additional nitrogen.

Why prune an alder tree?      

Because the alder tree can reach quite a height, it only requires minimal pruning once mature to keep it looking its best and of course, in good health.

Young alder trees benefit from formative pruning to retain a good shape. Smaller branches growing off the central leading trunk that fall below the larger branches can be trimmed off. Young shoots sprouting from the trunk, and root suckers, should also be removed as part of this process.

It is also a good idea to thin out any branches that rub against each other or are causing congestion, as this will encourage better air circulation and light penetration, both essential to maintain the good health of the tree.

As with any tree, it is important to remove any dead or diseased branches as soon as they are detected. This will prevent any issues from spreading to the rest of the tree. Be sure not to tear the bark or the wood though, as this can lead to an influx of bugs or even ingress of disease.

When is the best time for alder tree pruning?

Formative alder tree pruning should ideally be carried out during the winter, when the tree is not actively growing. This prevents sap bleeding, which tends to attract bugs, which can bring with them bacteria leading to disease. Suckers can be removed between late autumn and winter.

Any hazardous branches detected should be dealt with immediately, although it is wise to call in a qualified tree surgeon who will know precisely how to deal with their safe removal. They will also be able to investigate whether the remaining part of the tree is healthy.

What to look for when pruning an alder tree

The alder tree is susceptible to aphids and leaf-mining sawflies. Any infestation should be dealt with by careful pruning.

Phytophthora root rot, also referred to as alder dieback, is a known issue in the UK. It is a type of fungus that leads to abnormally small, yellow leaves that fall prematurely in the summer. Look out for dead twigs and dead branches within the crown as well as bleeding from the bark that forms brown, rust spots. You may also see abnormally large quantities of cones, which is a sign of stress. The tree may demise quickly, although sometimes it happens over time. Never hesitate in seeking professional assistance from a qualified and experienced tree surgeon should you spot any of these symptoms present in your alder tree.

Tree Preservation Orders

You should always refrain from proceeding with any tree work until you are absolutely sure that there is no Tree Preservation Order (TPO) in place. If there is, you will need to obtain permission before proceeding, and this can take up to eight weeks to be provided. Furthermore, if the tree is located in a conservation area, permission must be gained before commencing works of any kind.

The importance of alder tree pruning expertise

The alder tree is environmentally important, and it is an attractive tree too. If you want to ensure it is kept healthy and looking its best, the utmost care must be taken over it.

You should never hold back in bringing in the expertise of a qualified tree surgeon if you have any doubts about the best way of caring for your alder tree. Their experience and skill will make all the difference. Just make sure you are diligent in choosing your tree surgeon. They should be able to present official certificates and checkable references. If you can, use a Trading Standards approved tree surgeon for a guarantee of quality and good value.

If you have an alder tree that requires pruning, why not contact T.H. Tree Services? As fully qualified and extensively experienced Trading Standards and local authority approved tree surgeons, we can deliver specialist expertise across all aspects of alder tree pruning. For a free, no-obligation quotation, get in touch with our friendly experts on 01268 642814 or get in touch here.

When Should I Prune my Aspen Tree?

When Should I Prune my Blackthorn Tree?