How do I tell if my tree is stressed by hot/dry weather (or just stressed)

Hot and dry weather can induce stress into trees (and plants).

This is due to either the heat and the lack of moisture (or both).

To start with the leaves can look limp/wilted and/or lose their lustre.

If the situation is not rectified (watering, moving potted plants into shade (and watering), the next phase is the tree thinking, it makes more sense to loose some leaves that keep loosing moisture through them. Some of the leaves (sometimes all), turn their autumn tints and then fall.

If any of the above occur your tree is stressed.  You need to water (taking care you do not over water), frequently, ideally morning and evening, until the weather has passed.  Then continue watering over summer at a reduced rate.

The loss of leaves is a reaction to the conditions, typically the tree keeps the branch alive*, new leaves may be produced this year or next.  If the stress is extreme the tree will dieback in then canopy to a size that it's root system can support**.

Another reaction that the tree could produce to being stressed is basal or epicormic growth. These are new young branches that appear from the base, trunk or bases of branches. These grow fast and straight as they are diverting energy that the tree does not think is worth sending to the canopy.  For  this reason they should never see a Sunday, prune leaving a small collar (to make the surface area smaller and easier to repair).

* You can check if a branch is still alive  by scratching the bark to see if a small green layer just below the bark is present (the cambium). If it is the branch is still alive. If it is not the branch has died back to this point.

** If this occurs, let the tree dieback (whilst watering etc), it will withdraw reserves in its branches as it dies. If you proactively prune back before the branches die back the tree will lose this energy.

Black tubes (and caps) with planted trees

These tube are installed to encourage the formation of deeper roots, by delivering air and water lower down. This is advantageous for the tree, when drought conditions occur.

They are an unintended consequence though:

It is often used as the way to water trees, to the exclusion other methods.  The person watering is of the belief that when the pipe is full, the tree is watered.  WRONG.

When new trees are planted 100% of their roots are within the rootball.  It is these that should be watered, not the soil around and below the roots.  Watering through the pipe waters these areas only, outsides the rootball. Only a tiny percentage helps the tree.

For the first year 80% of the watering should be undertaken slowly over the top of the rootball. The 20% should go down the pipe. The watering should be undertaken to avoid runoff.

As the tree establishes the area around the rootball can be watered to encourage the roots to spread out.  

   

     

 

  

The RHS Chelsea Flower Show

We have nearly completed our stand at the Flower Show.  It is always interesting to see what trees have been planted in the show gardens, as the designers strive to create a winning garden.

I will report on personal highlights, ignoring the media frenzy at the show. What I hope for is more natural looking trees.

If you are visiting please call into our stand we would be delighted to talk trees with  you or catch up with  customers and friends.  We are in the usual place,but with a new stand number AR514, in the top right corner of the showground.    

Water your trees and shrubs!

We have had an incredibly dry March and April, following on from a relatively dry winter.

Please water your trees and shrubs if they have been planted or transplanted in the past five years or if they are showing signs of stress.

This will need to continue until we have a substantial, lengthy period of rain. This is not forecast. Any rain showers etc will have minimal effect.

It is possible that this dry period will extend into the normal  dry mid-late spring and summer, at which time watering of these trees will be needed.     

Sweet Chestnut Blight

This has been found for the first time at two sites in Devon. This will kill Sweet Chestnuts and can kill Oaks  in close proximity.

Unlike Oak Processionary Moth, where it was detected in the UK and the Government  failed to commit sufficient resources to keep the cat in the bag.  It is a great example of Government incompetence.   A larger upfront investment could have stopped a much bigger bill trying to get the horse back in the stable. 

http://www.forestry.gov.uk/chestnutblight

The fungus  Cryphonectria parasitica is spread by wind, rain, birds and insects.  The Government has to be prudent, clever and wise, spend the £ now, to stop this.  

Then a blueprint will exist on how to deal with other such problems.      

 

Trees - Noise Reduction

We get many requests from clients to plant trees to reduce noise. 

To get trees to reduce noise you need to plant a deep belt of trees (15 metres I read in one Austrian study).

The best way to reduce noise is either acoustic fencing ( https://www.jacksons-fencing.co.uk/acoustic-fencing.aspx ) or a soil bund (bank of soil).

Trees  mainly  only work in the mind to reduce noise, by screening;  if you cannot see the source of the noise, it seems to be less of a noise.

It is also important to understand the noise can only really be addressed at two locations, close to the source or close to where you are (as it bounces around).

We often recommend that a  noise consultant is used to provide expert advice, prior to any attempt to solve the problem.    http://www.association-of-noise-consultants.co.uk/  

If you are giving a tree as a present this Christmas

1) Fabulous, what a present, one that should last for generations benefiting people for decades or hundreds of years. It can provide a mix of benefits, ornamental, assist wildlife, screening, commemorative.....  It should last much much much longer than other presents.

2) Please ensure you select  the right tree for the right place, otherwise the tree will become a burden for others.  Seek advice from an Arborist.

3) Ensure that the tree will be planted correctly and cared for until established, (the point at which it can look after itself, as it's root system has grown to that of a natural tree (as opposed to  a nursery grown tree).  Please peruse the following link, which outlines most of the considerations and is applicable to all trees, not just memorial trees. 

https://www.ruskins.co.uk/memorialtrees

Root pruning

If time allows root pruning / root preparation  can provide huge benefits when transplanting trees.  If however specimens are being transplanted with sufficient rootball the benefits are negligible.

Roots are pruned at a diameter just inside the rootball size the specimen will be lifted with. This diameter has to be sufficient for the specimen, not what you can move! 

The reaction of the specimen is to stimulate root growth primarily along the length of the root, increasing the percentage of root mass lifted.

In addition by spreading the severance of roots over 2+ events, makes it less stressful for the plant and less energy is consumed repairing the cuts.

When root pruning, it is vital to provide a clean cut, a jagged or frayed root is much harder for the plant to repair and provides a much bigger potential area for infection. Do not use a minidigger! This can tear the root at any point upto the trunk and will create a frayed break. 

Ideally root pruning should be undertaken during the period November to mid-March.  When planning root pruning the maximum time should be allowed between pruning and transplanting within the above timescale. Root pruning stimulates a reaction, so a minimum of 3 months should be allowed.  If an extended timescale is available, the optimum will be Nov, Jan, Nov and move early Feb.        

Leave leaves please

Leaves are jettisoned by a tree, they fall to the ground and for eons, where composted where they fell and fed the roots /soil, providing energy to help the tree the following spring create leaves.....  

The original closed loop recycling process?

Then man came along and for urban trees, either removed the leaves with a OCD like drive or cut the grass so that it no longer held leaves.

Kew gardens (Tony Kirkham)  were the first in the UK (I believe)  to recognise this and politely told the volunteers who arrived every autumn to rake up the leaves that new thinking was in play.   They now mulch the leaves with mulching mowers (to cut them up into very small pieces) so that they are consumed by worms "overnight".  

This wisdom has now spread to the main central London Parks and they appreciate how the removal of leaves, removes food for the soil and this is compounded by the years of people walking over the root system. They have now set in process aeration and leaving leaves.

So, leave leaves please.   

   

 

 

BS8545;2014 - Why are councils not insisting on landscape scheme to this?

Trees planted as part of planning permissions are intended to be part of the landscape for decades to come.  Most frequently due to inadequate aftercare, poor choice of trees and inadequate planting specification, the landscape promised by the developers and approved by the Local Authority does not come to into effect. Trees are often dead, dying or in  a bad condition.

There is a solution, a British Standard, BS8545:2014 Trees: From Nursery to Independence in the Landscape. It ensures that:

Trees  selected for the planting area are suited to it.

They are planted correctly

The aftercare period is for 5 years, sufficient for the trees to have developed a root system that can support it and have "independence in the landscape"

Why are Local Authorities not stipulating this?  Do they intend for the schemes to fail? If not  why are they not using the best tool to ensure the landscapes are enjoyed by their communities in the long term.       

      

Mulch Mulch Mulch

To understand the importance of mulch one should talk a walk in a woodland.  Whilst trees look wonderful when looking up, for this purpose you should look down.

Trees have the original closed loop recycling going on.  The leaves fall and compost down adding nutrients to the soil.  Adding to this are twigs, branches and fallen trees all add to the composted nutrients. 

This layer of composting material is inches deep and slowly turns to organic rich soil.

Now think of trees planted in streets, parks and gardens, often they have bare soil, sometimes grass and occasionally shrubs. Some are even planted in containers.  Rarely do they have mulch.  

Composting mulch fuels the soil.

Trees should be mulched, in addition to the above, this will retain moisture in the soil, reduce competition from weeds and deters strimmers and mowers (which can damage the bark).

Ideally the mulch should be the by product of processing trees. Bark mulch is not desirable as it takes longer to break down. It is has leaves in it, it is ok, although these will take a bit of nitrogen from the soil as it composts.  The mulch should be composted.  The optimal mulch is ones that have been  processed through a mulcher with hammers. This is quicker to breakdown.

Mulch will increase Mycorrhizal activity by upto x15 that of grass (see previous blogs about this vital (for the majority of trees).  

This should be applied 3" deep as wide as possible.  The area immediately around the trunk should be kept clear.  It is not configured to be below ground. The addition of mulch up the trunk will create the same effect as raising the soil and will rot the trunk.

Mulch will compost down, so it should be replenished every 1-2 years.

         

Trees acting as though it was autumn in summer

A reaction of deciduous trees to stress (lack of water / too much water, too hot / exposed..) is to send a signal to their leaves that they are to be jettisoned. They are removing leaves, that transpire moisture (a cost) so that they can concentrate on their roots (this is simplified).

Prior to their departure from the canopy, these leaves adopt the autumn colours. This is a clear signal that is shown and indicates that an investigation into what is the issue and remedial action could be required.

If the leaves die and are retained on the tree, this is a sign that the stress is so severe that the message to drop has no got through.

Evergreen trees lose their leaves naturally from the inside of their canopy as they are shaded.  It is when this is magnified of the loss is from the entire canopy.

 

The damp and cool weather - why we are not disappointed

The damper and cooler weather is great for trees. The worst kind of weather dry/drought  especially when combined with high temperatures. 

When moisture is scarce trees can get stressed. When the temperatures are hot, trees transpire more in an attempt to cool down, losing more moisture.

The current weather provides plenty of moisture with mild temperatures, it is great for trees!

 

How to get a guideline cost for Screening Trees

We are happy to provide budget costs for potential clients. We would love to speak to you about your requirements and explain how we can assist you.

Whether you call us on 01277 849990, visit us at Great Warley or send an email to [email protected] we will need the following information:

Approximate height of screen (no need to be accurate at this stage, if you have difficulty estimating often just the detail of what we are screening (i.e. 1st floor window) or if you have a fence or wall, visualise putting the fence ontop of the existing fence (i.e. a 6ft fence ontop of itself will be a 12ft screen)).

Approximate length of screen ( again no need to be accurate, we can also translate "the length of a bus",  and " six fence panels").

Your location

Access to the planting location (through house (if this is it a straight line), side gate....)

An image would help of the area needing screening.

If you email, please provide us with your telephone number

Any preferences you have for particular trees or styles of tree.

We would love to provide you with the solution to your screening problem. Normally we can not only create a functional screen to provide you with privacy, that will also enhance your garden. 

It is a delight to see how clients appreciate our screening!  

   

The different canopy shapes of trees

At maturity trees can have a wide range of canopy forms, created naturally as opposed to created by training/pruning.

Canopies can range from upright, almost columnar (fastigiate), flame shaped, oval (upright), rounded,  domed, bell shaped and irregular.  They can occur from the ground or well clear stem themselves as they mature. 

With regard to the variety of clipped/trained canopies, this is making my head spin at present. Will attempt to outline these later.

Forms (shapes) of Trees available for planting

I will explain the forms of canopies in the next blog, this one is concerned with which you can purchase trees.

1) Standard Trees, these have a clear stem of around 1.8-2.2 metres with a canopy above. From this a half standard (1 metre clear stem) and three quarter stem (rarer but 1.75m) are derived.

2) Feathered Trees, these have branches from near the base, so that there is no area of clear stem.

3) Multi-stemmed Trees, these trees have typically between 3-5 trunks.

4) Pleached trees, are trees usually with a clear stem and then a pleached panel (with branches trained laterally). These can also be pleached to the ground (panels). Pleaching is the same as espalier but the latter is for fruit trees.

5) Roof trees, these have a clear stem and then a square flat (horizontal pleached panel) a top.

6) Cubed trees, a standard stem with a hedged cube atop.  

7) Topiary trees, these are trees with clipped canopies (in all kinds of forms) or trained trunks.

8) Hedged - these are feathered trees that have been clipped to form a denser canopy.

Have you planted or transplanted a tree in the past 5 years?

If you have done the above (and are in the northern hemisphere), your tree is still in a period of establishing.  When a tree is established it has the roots system of a 'natural' tree and can look after itself.  

This period of establishment can last for upto 5 years (and where there is competition from adjacent mature trees or the planting location is poor i.e. lack of rooting space, hard landscaping around the tree, surrounding poor soil, the trees could require assistance for longer).

This length of aftercare is recognised by BS8545:2004. It is appalling that no planning authorities are enforcing this (a far as I am aware).

The assistance required is primarily watering to compensate for the reduced root system, but also includes removal of epicormic/basal growth and should include mulching (see previous blogs).

Transplanted and planted trees must have this assistance whilst establishing,  after the investment in trans/planting, this will almost guarantee the success of your trees.  

Compacted Soils & James Bond

If you can recall the scene in Gold Finger where the girl is painted in gold and dies, the cause of her death is the same as what compacted soils do to trees.  Let me explain:

She died because her skin could not breathe.

Roots need to undertake gaseous exchange. When the soil is compacted this is reduced  or stopped.  The result, a decline/death of a tree is a result.

Compaction can be caused just by foot traffic, but more commonly it is the storage of materials or the traversing of vehicles /plant.  When the ground is damp it's effect is worse.

Air spades can relieve decompaction, but prevention is better than cure. Unfortunately compaction is usually caused when there is a lack of understanding/care about trees, soil and roots.