It's unseasonally dry!

If you have a tree (or shrub)  that has been planted or transplanted within the last five years or in a pot, please start watering them.  We have had 3-4 weeks of dry weather, at a time in the year when this should not occur.

Watering is best undertaken so that it penetrates deep into the ground, by slowly watering (drip irrigation is best for this). If your trees have an aeration/irrigation tube, only put around 20% of the water down this pipe.  The majority of the roots in newly planted / transplanted trees are within the rootball (or very close to it). It is therefore imperative to water across the top  of the rootball and immediate surrounding areas.  

Aeration/irrigation tubes are inserted to deliver air and water to lower in the soil to encourage roots and bypass  (although alongside) the rootball.  Whilst this is a beneficial, unless the tree is alive, it is of no use.

Cheap automated valves and drip irrigation systems are available from 

http://www.lbsgardenwarehouse.co.uk/Drip-Irrigation-and-Tools-DPTDRIPIRRI/

We recommend the following automated valve, it is not only the easiest to programme, but the cheapest.  Fit with a "splitter" to enable your tap to be used as normal

http://www.cityirrigation.co.uk/acatalog/Orbit-Buddy-single-outlet-Digital-Tap-Timer-CPORBAT01.html

Please call us if you need advice, although both of the above suppliers provide excellent guidance.

Trees coming into leaf

The bud swelling and leaf burst is not a good indicator of the health of trees. This change is chemically induced in response to longer daylight, stronger sun and increased temperature. The true test is if the tree can support this new growth.

 Leaf burst should be all over the canopy, if areas are devoid of new leaves or sparse, it is an indicator of stress, the tree can no longer support these areas of it's canopy. 

Please do not expect all your trees to come into leaf at the same time. Specimens of the same species may be in colder areas. Trees from warmer climates will be later into leaf.  

Why is mulch so good for trees? An idea

I  my view, it is because it is the closest the tree will get to being surrounded by the woodland floor, where (most of them) came from.

Does anyone have a view on this suggestion?  

BS8545:2014

I was asked on Friday to help a national charity with a large scale, multi location, community tree planting project.  Even though we would not benefit from this, spreading the love of trees is a passion of ours.    

In response to the question from the client of " What do we do to ensure success", at first I envisaged a long list of different factors that needed to be taken into account.  Then I remembered BS8545, it encompasses the selection of trees, where to plant trees, how to plant trees and then critically that they need looking after for 5 years whilst they establish (attain the root system of a "natural tree", when they can support themselves and have "independence in the landscape".  

I urged him just to state the works had to be done to the standard, but then realised that I would have to explain the long list of different factors so that he could assess if the tenders were to the standard.  It was still a pleasure to pass on what it takes to make a successful tree planting.    

Soil Health

Soil should be viewed as a living ecosystem, it's health underpins plant, animal and fungal growth.  It's is commonly understood that:

Soil can be lost through erosion

It takes a long time to create (the quickest estimate is 500 years and the longest tens of thousands of years).

Soils can be poisoned by pollutants or compacted.

An area often overlooked is that soils need to be healthy to function efficiently.

The link below explains the soil ecosystem and it's importance.      

http://www.nrcs.usda.gov/wps/portal/nrcs/detailfull/soils/health/biology/?cid=nrcs142p2_053868  

When considering planting or when investigating plant health issues, the health of the soil should be a prime consideration.

A common problem is caused by the annual removal of  leaves, which if left in situ are a closed loop recycling, providing the tree with vital nutrients, as nature intended.    

Spring Springing

As trees sense spring is starting (by a combination of longer daylight, increased temperature and stronger sun rays (caused by elevation of sun in the sky)), they send signals to buds to begin to swell.  

The buds will enlarge and then leaf burst will occur.

Please note this is a chemically triggered event, it is not an absolute indicator of the health of a tree. The acid test is whether the tree supports the new leaves.  

Just to confuse things late frosts can damage new leaves.  

Aftercare of newly planted trees and stressed trees, should commence as the buds swell to support this process and continue through spring and summer. It is recommended to assist newly planted (and transplanted) trees whilst establishing for upto 5 years. Established is when the tree can support itself.  During later extreme dry and  hot weather, the trees will always thank you for additional help. 

Trendy Trees (the merits of untrendy trees)

There are trees which have fallen out of foul of current trends.  Likewise there are some trees that are so ubiquitous that  they are often specified without taking into account the planting location.  Betula utilis var Jaquemontii (especially multistem), Pyrus calleryana Chanticleer,  Photinia fraserii Red Robin in my view, fall into this category, whilst they all have many plus points, doesn't the frequency of planting reduce this?  

Even where these ubiquitous trees are planted, don't  specifiers have an obligation to plant a wider range of trees? Are they being lazy just recommending the same trees over and over for different sites.

Tree Nurseries are always introducing new trees and new varieties of existing trees.  Whilst I acknowledge that these trees are often suited to; a warming climate,  planting in relatively restricted areas or clones that do not fruit, the nurseries after all that investment will push these trees, without the   knowledge of the specific planting locations possessed by the planter. 

A prime example of a group of trees that have fallen out of favour are Lawson Conifers.  These have a variety of forms and foliage colours. In addition they are relatively slow growing compared to other similar Conifers and mature at smaller sizes.  

We appreciate that if there is not demand from specifiers, growers will be less likely to invest in un-trendy trees,  due to a combination of cost and risk of not selling them, but how do we break this cycle?     Even is there a need to break this cycle?   

Strimmer Damage

It is heart breaking to see damage to the bark of trees caused by strimmers.  After all the hard work that has gone into selecting the right tree,  paying for the tree, planting the tree and then caring for it to ensure it establishes a moments error by a strimmer operator can cause irreparable damage, to a tree.  

If a very bad case or repeated damage, this can kill the tree.

Solutions:

Training operators of strimmers can be on great benefit.

Mulching 3" deep as wide as you can, with the immediate area around the trunk kept clear, can keep the area weed free, negating the need to strim. Mulching also has massive other benefits for the tree. 

Protecting the lower trunk with a strimmer guard will prevent damage.  These are available from suppliers, but you can also use a length of plastic drain pipe but vertically split to allow for future growth. We can put you in touch with suppliers.

Weedkiller can be carefully applied but we would rather not recommend this, it needs to be applied as per manufacturers recommendations and cannot be sprayed on the trunk (as the trunk will absorb it).

You could weed by hand (if a reasonable task) 

Right Tree Right Place

Whilst it is hugely beneficial to plant a tree, when selecting which tree it's future size should be a primary consideration.

The real benefits from a tree come when it is  middle - mature in age., when it is near or at it's maximum size.   Unless it has the space to grow into this size, as a minimum it will need to be pruned on an on-going basis to restrict it's size or it will be felled.   

A competent  arborist will be able to visualise a tree in 100 + years time and assist  by recommending a tree that will be able to mature in it's location.  

Flexing in the wind helps trees

We get many calls from tree owners worried about trees flexing in the wind.  Conversely we get no calls regarding trees that have been planted too rigidly, so they cannot flex.

Flexing sends a message to the roots, that they are required, even to the point of where they are required (i.e. prevailing wind). Without this stimulation roots have less incentive to extend.  

This has the by product when it gets drier, there is less of a root area for the tree to garner moisture.

It is when trees do not return to vertical or if the trees are dead and have no flexibility you should call an arborist.

Being a re-assuring constant

This week, we returned to a large domestic property to plant pleached Hornbeams for a well known Garden Designer.  The resident was very pleased to see us.  We had been the specialist contractor for her previous (well known) Garden Designer.

It was nice that she remembered the name of our foreman, but incredible that this knowledge also stretched to how he like his teas!  

Autumn Leaves - What to do with them

In nature, the leaves that fall, remain either where they fall or close.  

They are then broken down by natural processes to  provide organic matter for the soil organisms, which in turn create the environment or nutrients for the Mycorrhizal fungi and roots. These  feed the tree, enabling the tree to grow a full canopy of leaves, which provide the tree with energy through photosynthesis and then fall in autumn.      

It is a closed loop recycling process. 

IF you can, this autumn leave the leaves where they fall to feed the tree. This can be speeded up by mulching the leaves, this can be down by mowing the leaves, without the  collector off, so the chopped up leaves fall to the ground  But check for hedgehogs first!

Tony Kirkam for Kew uses this process at Kew, he swears the leaves are chopped up so fine, the worms manage to take them into the ground at such a rate, there is nothing left in 24 hours!  

Try this let me know if the worms achieve this.

Grass vs Mulch around Trees

We urge you to have mulch around your trees in preference to grass or just soil. Whilst grass can have deeper roots than trees, effectively out competing them for moisture and nutrients, this is not the main reason for this.

Mulch will increase Mycorrhizal populations by up to 15 times that of grass.  This leads to a much healthier tree.

Mulching is the closest a tree will get to the floor covering of a forest. In a forest the recycling of organic matter, feeds the soil, which provides the roots and their fungi with their nutrients. On a much smaller scale your mulching will also assist.

Epicormic Growth

This growth occurs on the trunk and at the bases of branches. It is straight in nature and grows very quickly; this  is because it is diverting energy from the canopy.   This diversion of energy from the canopy is very detrimental to it and will weaken it, even leading to dieback.  

If it is never allowed to see a Sunday and is removed frequently the energy can be retained within the canopy.

When pruning, leave a collar on the cut, do not pare it back to the bark. This leaves a smaller surface area for the tree to repair.   

Trees in containers

There are some circumstances when this cannot be avoided, but please realise how alien this is to a tree.  It will require watering  more frequently, when it exhausts the soil (preferably before), it will require  feeding and top dressing. Once you have conquered these elements, you will be faced in time with the tree becoming pot bound. 

We had one lady who brought a Swedish Birch over to London when she came to live here twenty plus years ago, (in her hand luggage) when it reached a  decent size, she planted it in a plastic dustbin.  Whenever it split the dustbin,  the  dustbin was cut away, a bit of the root and soil removed and it was replanted in another plastic dustbin.  This created a large bonsai Swedish Birch in wonderful health.

For those of  you with trees already in containers,  you could lift the tree out and place it in a larger pot, but at some stage this will become a bit of a problem,  the tree could be lifted out and root pruned (like a bonsai).  We suggest however  it can be re-planted in a tree (root) friendly container.      

Call us to find out how.

BS8545:2014

 This new British Standard explains how to select trees, plant them and care for them.  The most important part as we view it is the emphasis on 5 years post planting aftercare.  If only this was to become the standard to which main clients and Local Government applied to tree planting, it would ensure that when a landscape scheme is agreed, it will come to fruition and as a high quality scheme.   Not only would this transform the local environment, but it will also contribute to a wider improvement in the general environment. 

Nearly (RHS) Chelsea Time

Got a busy week ahead setting up for the Chelsea Flower Show.  The delayed spring will allow us to use different flowering shrubs and trees. I hope the garden designers and their show gardens, have some flexibility in their plant choices (think the RHS will not allow this). Going to spot the flowers not in bloom and leaves not out.

Might have an office sweep stake on it!

Optimum Time to Plant /Transplant

The optimum time to plant or transplant is from late September, then by incremental changes, less favourable until next summer.

The earlier trees, hedge and shrubs are transplanted during this  period the longer they have in their new locations, to begin to establish prior to it becoming hot and dry. This enables them to start to create a root system to support themselves.  This reduces planting/transplanting stress, the level of aftercare required and increases the quality of transplant.

Deciduous trees/hedges/shrubs transplanted in autumn, before leaf drop, in our experience only enter autumn (leaf fall) phase early.

The benefit of planting/transplanting early in this cycle is only marginally eroded as the calender progresses.

Later in this period the planting/Transplanting process does not need to be amended until it gets into Spring and Summer. We amend the process with larger rootball if transplanting / root preparation  and always increased aftercare.  Also we cut down the time between delivery and planting of trees and shrubs.

A late spring now for a cool wet summer

As arborists we are very sensitive to how the  weather impacts on trees.

The late spring has been very benefical for trees, especially newly planted or transplanted trees.

Whilst we like nothing more that sunny weekends so that we can go out and about with our families and enjoy our gardens, but we really prefer cool, wet summers.

Trees get stressed by hot temperatures, especially when combined with dry winds and prevailing dry weather.    This can be multiplied when planted around hard surfaces / buildings (reflected heat) or when there is insufficent rooting area (unable to access moisture in the ground).

Newly planted / transplanted trees have to rely on humans to water them, whilst they establish (extend their root system to that of a normal tree). Often the will, resources and competence  are not available to these trees.

This lack of watering can have devasting results to these 'new' trees. When there are drought conditions, especially when the water table drops, even established trees can suffer.

Mulching of both newly planted/transplanted trees  can greatly assist trees, by retaining moisture within the soil, reducing competition from weeds and grass (which often have  root systems that can extend down as far as trees), slowly adding organic matter to the soil but most importantly increasing Mycorrhizal  activity by upto 15 times over grass.

Chelsea Flower Show

It should be an interesting Show this year, spring is around 5 weeks late, many of the trees and shrubs will not be doing what their designers hoped.

With the long winded design approval process, I wonder what the judges will make of it.

It will be a pleasure to meet any visitors to the show, we are in the top right hand corner of the showground (with your back to the Thames). Our stand number is MR1.

There are two exits to the showground, the Bullring to the south (Thames) and the one in the north east which takes you to Sloane Square Tube.  If you leave by this last one, you will walk past us.  If you enter from the north, turn left as you enter and we are 50 yds on the right.