Archive for the ‘ Technical Advice ’ Category

Site supervision

Posted Thursday, 11 July, 2013 at 12:41 pm

One of the services I offer is to monitor the progress of the site during the construction works.  This service is shown as a stand alone cost for the client to decide if they wish to use this service.  Why do I show it as a stand alone cost?  The answer is simple.  It means I am there to represent the clients best interest not the contractor.  Some designers employ contractors who load their quotation with a hidden fee (back hander for the designer), I don’t.  This is a practice that should not be followed, but it is always worth asking your designer if there is such an agreement with any of the contractors nominated by the designer.  As a member of the Society of Garden Designers I follow a strict code of conduit which prohibits such activities.  I would rather show the client the cost and be honest, upfront and transparent.

By showing my figures up front I do risk clients not utilising this service.  By employing the designer as a monitor they obtain my services enabling the contractor to call me throughout the contract, discuss and respond to their questions and those of the client quickly and if needed visit the site to clarify and advise on site any issues.  This saves down time for the contractor and ensures that the right response to the situation is taken rather than the easiest for the contractor, who may not realise the implications of moving a path or changing the level of paving.  Knowledge of best practice is vital and I often visit sites where old and incorrect methods of laying slabs are still be used.  This is often not seen as a problem by th client until a few years later when the terrace fails and slabs start to rock and move.  By that time the contractor is long gone and the client faced with a project that needs repeating.

Using my service provides the client with over 25 years worth of construction knowledge gained within a design and build landscape practice in suffolk, Norfolk and the West Midlands.  This knowledge of construction is often missing from some designers who have the impression that if it is drawn as a plan view it can be built.  Not so. I have many times whilst working on others plans found major constructional flaws.

Generally I charge £100 per visit which includes my travelling allowing an hour on site.  With a project I will generally aim to visit once a week to review progress and inspect work and materials ensuring that the work is being undertaken in accordance with the specification.  The relevance is important for if you have obtained detail costs from three contractors and the contractor you commission does not adhere to the specification you are not getting value for money and the other two contractors will not have been costing on a like for like basis.

As a professional I can only advise my clients but in submitting this blog I hope they can see the value in paying for this as a way of ensuring they get the garden they deserve.


Seen sites hat have been carried out without such supervision I am often presented with a project that has been completed but some element have been skipped upon.

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Why use a specification?

Posted Tuesday, 14 February, 2012 at 1:21 pm

Why use a specification?

The purpose of a specification.

The main purpose of a specification is to provide sufficient descriptive information about the project including the quality of materials and workmanship.  This information together with the completed drawings provide the necessary information for a contractor to realistically price the work and subsequently build the project to the standard required.

For the client:

  • The information enables them to obtain like for like quotations ensuring all tendering parties are quoting for the work described rather than based upon their interpretation of the drawing.
  • Ensures the client will get best value of the job.
  • Conveys best practice ensuring the site will be kept tidy, that the storage areas will be placed where they cause minimal disturbance.
  • Protects clients from added extras that were missed out from the costs because the scope of works was not clearly defined.
  • Should there be a disagreement over the building of the garden the methodology can be tested against the specification and if the contractor or designer are at fault there is course for address.


For the designer:

  • The specification provides the opportunity to convey information that could not be shown within the drawings alone.
  • Ensures the contractor and client have all the information to make and receive accurate costs for the project.
  • Ensures the project will be built in an approved manner following best practice.


For the Contractor

  • Accurate costs for the project can be determined as the information is available supporting the drawings.
  • Provides a fair quotation framework ensuring the prices can be compared.
  • Prevents competitors undercutting their quote by using inferior materials or omitting elements to secure the work.
  • Protects the contractor by detailing all elements and materials required.


From whatever side of the fence you site be it as the designer, contractor or client a specification is a must for most projects.  External Designs has recently invested in a detailed specification model and will be urging clients to consider the fee as an essential part of their projects costs.

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Maintaining your Ornamental Grasses

If like me you will enjoy the benefits ornamental grasses can add to a planting scheme.  Their height and movement add vertical elements into a flower planting scheme that  few other plants can.  Their presence can serve as either an accent in a planting scheme or as a dramatic mass planting.  Added to this movement you have a wide range of habits, forms and colours which if used carefully can provide tremendous value to the winter garden.  With a range of seed heads that can be extremely fine such as those of Deschampsia or more dramatic such as the large and well know feathers of the Cortaderia

Maintaining ornamental grasses is straight forward and easiely managed by even the novice gardener making this an ideal plant for those new to gardening or those wishing to have an easy plant within their garden. Observation is the key to a successful gardener and visiting the garden at regular intervals will often provide clues as to how to treat the grasses.

To begin with you need to identify whether your grass is a deciduous grass or an evergreen.  The term deciduous within the grasses refers to the fact the grass turns a golden yellow/brown colour in autumn rather than maintaining its foliage colour.  Grasses such as Stipa, Miscanthus, Deschampsia and Calamagrostis are all deciduous whereas Festuca and Carex would be considered evergreen grasses.

Grasses within my garden such as Stipa tenussima, Calamagrostis ‘Overdam’ and Deschampsia ‘Goldtau’ are all cut back to about 100 mm above the ground in early spring (early March) the new growth then emerges providing new stems and leaves aplenty.  I am more careful with my Miscanthus varieties and tend to leave the stems until the end of March allowing for the early signs of growth to show.  Then using my faithful pair of Felco’s I cut the culms (old stems) away. I usually cut my Miscanthus down in stages firstly cutting the stems back to about 300 mm above ground level allowing me a better view of the emerging new growth.  Then carefully reducing the stems to about 150 mm.  Once completed tidy up the crown removing any dead leaves and weeds.  Appling a general-purpose fertilizer to the surrounding area once completed will encourage new lush growth in the spring.

Evergreen grasses such as Carex require a different approach.  They are not cut back hard instead the objective is to tidy the plant up removing spent flower stems and dead leaves.  This is a slow task but worth undertaking.  Event drawing your hand through the leaves will dislodge spent stems making the grass look more attractive.  Once this task has been completed you can tidy up the surrounding area and feed the grass in the same manner as the deciduous grass.

There comes a time when grasses become too large for the space or have become old and tired and would benefit from a new start.  Dividing achieves these two objectives and will produce multiple new grasses that can be given to friends and family or simply utilized in your own garden to create a more dramatic group of plants.

Understanding the type of grass again is important and like the previous section you need to know whether your grass is either a grass from a cool or warm climate.

A quick guide:

Grasses from cool climates will include Carex, Molinia Calamagrostis, Festuca, Chasmanthium, Deschampsia, Hakonechloa, Helictotrichon, and Stipa.

Grasses from warmer climates will include Miscanthus, Phalaris, Cortaderia, Imperata, , Panicum and Pennisetum.

Cool Climate grasses require frequent division, perhaps every three years, to prevent root congestion and loss of vigour.  They are best divided as they come into growth in late winter to early spring and within a season will have started to make a mark within your border.

Warm climate grasses will only gradually increase in size and will require infrequent division to manage this slow spread. As these grasses don’t come into growth until late spring, they are best not divided until late spring.

To divide the grasses you need to initially lift them out of the ground to then allow you to split them with either a pair of garden forks or by chopping them with a spade.  Some grasses such as Miscanthus have a very tough root and I tend to uses an old but sharp knife to cut my way through the roots.  When dealing with smaller grasses such as the Festuca it is possible to use your hands to split the clump. Some Miscanthus and Cortaderia can be tough on your hand producing deep ‘paper cuts’ that sting disproportionately to there size.  To protect your hands when dividing it is therefore advisable to use a good pair of gardeners gloves.  Eye protection is advisable as it is easy to become so focused on the root and ignore the stems, which can stab into the eye causing permanent damage.  Try to keep your grass divisions as large as possible.  If the divisions are going back into the garden immediately you will find they establish faster if they have not been reduced too greatly.  Small divisions can be potted up in a John Innes No.2 compost before planting in the garden once the root system has established-lift the pot to see if roots are showing through the drainage holes.

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Damage caused by dog urine to lawns

Posted Sunday, 29 January, 2012 at 11:35 pm

As an owner of a dog I am all to aware of the damage my dog makes of my lawn.  This fortunately is mainly due to his physical movement tearing the lawn up which becomes more of a problem during the winter.  However as a male dog he does not cause the burning of my lawn as like most male dogs they tend to use urine as a scent marking and will pass small quantities for such a purpose.  Bitches tend to pass a greater volume of nitrogen rich urine. Whilst nitrogen can produce a fertilising effect that promotes growth, large amounts will result in the burnt bare patches that appear within a lawn.

The most effective solution is to simply spray the affected area with copious amounts of water as soon as possible, to dilute the urine and reduce the impact of such a high nitrogen content within a localised area. You could also try adding horticultural lime or powdered gypsum to the water, as this will neutralise the acid. Finally, try to prevent the problem by encouraging your dog to urinate in a designated area of the garden. Some products on the market include a ‘pee post’ which is a pheromone treated garden stake used to attract and encourage your dog to urinate in a particular spot.
It is difficult and vigilance is needed if you are after that green lawn without those annoying brown patches.
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Remembering a visit from the a sustainable community I came across this article extolling the virtues of saving your urine and using to promote your compost.  Having read it I thought it would be good to share:

original article written by:

Dorienne Robinson


Ever felt the urge to skip the toilet and just pee in the bush, behind the tree, in the flowerbed? Have you ever wondered why we have been so conditioned to hold on to a screaming bladder while we search for the nearest toilet, which could be many minutes away, meanwhile putting certain internal organs through extreme stress?

There are public decency laws to respect, and for women there are obvious added complications surrounding the degree of derobing that may be necessary, but we shouldn’t be wasting this ultimate homemade fertiliser. Most of us may have a deeply ingrained belief that urine is a noxious substance that must be disposed of in a urinal, but this is a myth that needs busting.

Urine for a pleasant surprise

Human urine is one of the fastest-acting, most excellent sources of nitrogen, phosphorous, potassium and trace elements for plants, delivered in a form that’s perfect for assimilation. Not only that, we all have a constant, year-round supply of it – and it’s free!

Fresh human urine is sterile and so free from bacteria. In fact it is so sterile that it can be drunk when fresh; it’s only when it is older than 24 hours that the urea turns into ammonia, which is what causes the ‘wee’ smell. At this stage it will be too strong for use on plants, but poured neat on to the compost heap it makes a fabulous compost accelerator/activator, with the extra benefit of adding more nutrients.

Dilute one part urine to 10-15 parts water for application on plants in the growth stage. Dilute in 30-50 parts water for use on pot plants, which are much more sensitive to fertilisers of any kind. Trees, shrubs and lawns are fine with undiluted urine, but for obvious reasons apply it underneath fruiting bushes, as opposed to directly on to foliage and fruit. Some fertilisers, such as seaweed, are specifically used as foliar feeds [applied direct to leaves], but urine is always best applied directly to a plant’s root system.

Antibiotics, vitamin supplements and other medications will end up in your urine, but in such minute quantities as to be negligible, especially when diluted in water.

What is wee?

Urine is 95 per cent water, 2.5 per cent of which is urea, and a further 2.5 per cent of which is a mixture of minerals, salts, hormones and enzymes. It is a blood byproduct but despite containing some bodily waste is non-toxic.

In 1975, Dr A. H. Free published his book Urinalysis in Clinical Laboratory Practice, presenting a few of the critical nutrients found in urine, including urea nitrogen, urea, creatinin nitrogen, creatinin, uric acid nitrogen, ammonia nitrogen, amino nitrogen, sodium, potassium, calcium, magnesium, chloride, inorganic sulphate and inorganic phosphate.

During a pee, a healthy adult will release 11g nitrogen/urea, 1g phosphorus/super-phosphate and 2.5g potassium. Patrick Makhosi, a soil scientist with Uganda’s Kawanda Agricultural Research Organisation, confirms the efficacy of human urine as a fertiliser. He says that applying urine to growing vegetables once every week for at least two months will more than double the yield.

Flushed with embarrassment

Many toilets use between 50 and 100 litres of water a day to flush approximately 1.5 litres of pee. The average person has five wees a day and the average flush uses eight litres of water – that’s 40 litres. Given that the population of the UK is an estimated 62 million, we may be contaminating and then flushing away somewhere in the region of 2,500 million litres of clean drinking water every day. (Returning our waste water to a drinkable condition also involves a complicated process of chemical separation and cleaning.) If this were an action by a commercial company, serious questions would be asked about its practices. Diluting urine to use as a fertiliser would use a fraction of this amount of water while producing a valuable plant food.

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How to choose a Professional Arborist

Posted Wednesday, 30 November, 2011 at 4:45 pm

Why choose a professional arborist?

Tree work is a dangerous and highly skilled operation. Choosing an arborist is something that must be done with great care. Picking the wrong arborist could lead to:

  • Injury to people,
  • Damage to property,
  • Irrevocable damage to your trees that have taken many years to grow…

Tree work operations (arboriculture) require a high degree of technical competence, supported by training and experience. For these reasons tree work should only be undertaken by well trained, competent arborists who hold adequate insurance.

Genuine or not?

Anyone can call themselves a tree surgeon (arborist) and place an advert in Yellow Pages and offer a service. An advert alone does not guarantee quality of work or that it will be carried out safely.

Competent arborists will have certificates which show that they have been trained and assessed. They will often have other academic qualifications in arboriculture and will use safety equipment to protect you, your property and themselves.

Reputable tree care companies will be pleased to furnish copies of their insurance, qualifications and professional memberships and will work to nationally recognised standards.

Detailed questions on how to choose the right Arborist is available from the Arboricultural Associations web site as a downloadable PDF file.  It provides questions that will assist in finding the right tree surgeon.

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Does your drive need planning permission?

Posted Tuesday, 29 November, 2011 at 9:53 am

Does your drive need planning permission?

From 1st October 2008 the permitted development rights that allow householders to pave their front gardens for hard standings without planning permission has changed. Planning permission is now required to lay traditional impermeable driveways that allow uncontrolled runoff of rainwater from the front gardens onto the road because this can contribute to flooding and pollution of watercourses.

If a new driveway or parking area is constructed using permeable surfaces such as permeable block paving, porous asphalt or gravel or if the water is able to soak into the ground via soil borders or a soak away you will not require planning permission.

These new planning rules also apply to where existing hard standing are being replaced and apply to hard surfaces exceeding 5 square metres in area.

Applying for planning permission will require you to fill in an application form, draw plans which have to be to scale and pay a fee of £150. Planning applications for this type of development should normally be decided within 8 weeks after submission

Why this is required?

Hard surfaces lead to accelerated run-off of surface water, which can overload sewerage systems in more urban areas. One of the main factors that contribute to such run off surges was the increasing number of hard surfaces over front gardens to provide off-road parking. This problem is likely to intensify as climate change produces more torrential downpours.

The Governments response was to require that paving installed using permitted development rights does not make this problem worse.  In future paving in front gardens will not be granted permitted development rights unless the surface allows the water to drain away naturally.

This can be achieved in a number of ways – most simply by ensuring that water runs off to an unpaved area such as a garden border providing the falls are sufficient and that running water into to this area will not cause problems for your neighbours.

SUDS – Sustainable Urban Drainage Systems

When considering dealing with rainfall is a serious consideration and needs to be considered carefully. During a typical storm, high volumes of water can fall onto the large area of a car park or driveway, and this has to go somewhere.

Often there is no one correct drainage solution for a site. In most cases, a combination of techniques may be required.   A professional designer will be able to discuss the various options with you to ensure the water management has been considered.


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About Tree Preservation Orders (TPOs)

Tree Preservation orders or TPOs were introduced to enable Local Planning authorities to protect important trees.

TPOs can be placed on any tree that has amenity value. Trees that are exempt from TPOs are those that are dead, dying, diseased or dangerous and fruit trees grown for the commercial production of fruit.

TPOs prohibits the cutting down, uprooting, topping, lopping, wilful damage or wilful destruction of trees without our consent.

The maximum penalty for carrying out works to TPO trees without consent is £20,000.

Our policy is only to protect trees that are under a direct threat.

For a guide to the law and best practise on Tree Preservation Orders please see Tree Preservation Orders: a guide to the law and good practice on the Communities and Local Government web site.

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