Brick wall thickness

The convention for describing the thickness of a wall is relative to the length of a brick so goes like this. It may seem counterintuitive but as its long established deviating from it will lead to confusion.

A ½ brick wall which was sometimes called a 4 inch wall is:

A half brick thick brick wallA half brick thick brick wall

A 1 brick wall which was sometimes called a 9 inch wall:

 A one brick thick brick wallA one brick thick brick wall

A 1½ brick wall which was sometimes called a 14 inch wall:

 A one and half brick thick brick wallA one and half brick thick brick wall

And so on, so the next is a 2 brick wall (18 inch wall) and then a 2½ brick wall (22 inch wall).


This is anything constructed from bricks which are normally fired clay, yes we are really still building from mud! The small size of the individual bricks makes brickwork and incredibly flexible building material to make garden structures out of.

A few points to note:

  • The thickness of a brick wall is described relative to the bricks length so the wide of a wall goes up in half brick steps starting with a ½ brick.
  • The mortar between the bricks is there to keep the bricks apart and stop them wobbling, it DOES NOT STICK the bricks together! In fact to an engineer brickwork has no tensile strength, that is to say it has little or no strength when being pulled apart.
  • Most bricks have little resistance to frost when wet so unless engineering bricks are being used things like retaining walls will need to have the brickwork protected from moisture.


This is a pattern that tied individual components together both structurally and visually and comes in a variety of styles including stretcher, Flemish, English, English Garden Wall, Herringbone and Random.

To sow or turf

Once we have decided to create a lawn one important question has to be tackled – are you going to do it by sowing grass seed or by turfing and each has its pros and cons.



  • Cheaper
  • More tolerant of drying out
  • Needs better preparation
  • Can only be done when frost is not a danger
  • The mixture of grasses shown can be tailored according to the use
  • Once the ground is prepared the seed will be fine in the bag for months if the weather makes sowing undesirable
  • Borders have to be cut out after the lawn is established (there is away round this I will come back to)



  • More expensive
  • Must not be allowed to dry out until it is established
  • Quicker result
  • Water supply aside it can be done anytime of year
  • Physically harder work
  • Less choice regarding the grasses chosen
  • Must be used as soon as it is delivered
  • Borders can be formed as the turf is laid


In short turfing will allow you to create a lawn any time of the year so long as you can work the soil but it must not be allowed to dry out until it is properly established and each roll of turf weights about 15 to 20 kg so a small lawn will involve humping about several tonnes of turfs. Seeding is cheaper and you have more control over the types of grasses to end up with –something else I will have to come back to – but needs longer to make an established lawn.

Buying for the garden

One of biggest problems that retailers selling to gardeners have is names. Plant names, chemical names, compost names, what ever they try to sell to gardeners there always seems to be some impenetrable name between the product and the customer. How the shop handles this divides the good from the rest. For it is not an insurmountable problem but it does call for a real investment in their staff, not just in monetary terms, the culture within a workforce is what makes the biggest difference irrespective of if it one small shop or a national chain. A happy motivated worker is going to make the effort to understand the things he is selling and a good employer is going to make sure they have the support to make sure they have the time and the opportunities to keep that knowledge up to date. This is because the thing that makes a good garden supplier stand out is product knowledge and if you walk into the shop and is greeted with an absence of clear and well informed advice turn round and walk out. The good ones, and there are plenty out there, need your support if we are to keep them.

The great grass seed swindle!

In about the last 40 years grass seed has undergone a revolution, when I was an undergraduate perennial rye grass was the tufty grass you tried to avoid in anything but the areas of long grass due to its course nature and inability to tolerate close mowing. Suffice to say things have changed a lot with the discovery that you can selectively breed grasses and so dramatically alter their nature, particularly the case with rye grass. Now very few commercial grass seed mixtures contain no perennial rye grass cultivars in their make up. This is because modern perennial rye grass cultivars still have the good wear resistance of their wild type but the nature and tolerance to close mowing of the traditional finer grasses. This has lead to a proliferation of hundreds of different grass cultivars each with their own characteristics, strengths and weaknesses. Every year the STRI (Sport Turf Research Institute) and the BSPB (British Society of Plant Breeders) publish a buyer guide to the available grass seed varieties and the 2012 edition runs to 32 pages! With all this variety how are you going to the right choice? Lucky this is done by the seed merchants and all grass seed is now sold in mixtures. Now comes the problem, because how good these mixtures are can be very variable.

Can we trust the packaging

Mixtures from the big seed houses are very good as they are supplying the professional market and have a wealth of specialist knowledge to back up their choices. You only have to look at recordings of a late season football match from the 1970’s and compare the pitch to a late season match now. Unfortunately you are unlikely to see these on the shelves of the local supermarket or DIY shed, and even if you did you the name would nothing to you as they sell to people like golf and football clubs, and landscapers who buy grass seed in multiples of 25 Kg sacks. The people at the STRI began to wonder if all the advances made in turf culture over the years had filtered down to the domestic market so in 2009 they started to investigate the quality and performance of the grass seed mixtures which were aimed at the home gardener. This wasn’t greeted with enthusiasm by some of the retailers, claiming as the seed mixtures changed from year to year by the time the trials would be completed the mixtures would have changed so the results would be out of date. Fortunately the STRI pressed on sighting the argument that trail would show if the mixtures matched the description on the packet they came in. Unfortunately for the consumer STRI are not Which, consumer protection is not what they do, it was fortunate for the retailers since they would not want the trial results given the kind of press coverage Which would have given them. They were not good.

Does it do what it says on the box?

By their own admission the trials are in an early stage but in their April 2010 Bulletin they had already come to the conclusion that the quality of the mixtures was VERY variable and the price on the box was no indicator of the quality of the content. The mixture appeared to be made to price not purpose so the consumer had no way of knowing if the mixture was really suitable for them. In any walk of life this would have coursed a public outcry and the retailers would have had their PR people running round like scolded cats. The STRI is a professional research organisation for the horticultural industry so sadly no one noticed the damming report they produced, and I’ve read a few research bulletins but none I can think of which were this bad!

The mixtures ranged from reasonable to ones which were only really suitable for a farmer’s field, I know self sufficiency is coming back into fashion but keeping a house cow might be a step to far.

So what to do?

From the report and the deafening silence that has followed it I think it fair to say buying your grass seed from a supermarket, DIY shed or most large garden centres is going to be at best the horticultural equivalent Russian roulette. So what would I do? Well head to an independent garden centre or similar place and have a wander about. Look to see if the grass seed is in nice shiny little boxes on the shelves. If it is I’m afraid your best bet is to keep looking. On the other hand if the grass seed is being dolled out of large paper sacks in the floor and the sacks are rather plain you are in a much better position. Have a look at the brand name, ask the staff about it, google the name and see if a big specialist grass seed company, do a bit of research, you are going to be living with this mixture for many years to come. That way you should get a grass seed mixture which reflects the quality out there and not left with the stock room floor sweepings. Clearly a case for “Caveat emptor”!


This is a layer of crushed stone used under paving to form, in effect, a stable foundation for it and is found between the bedding course and the subgrade. It is made of stone which has been crushed and sieved stone to end up with a mixture of sizes from  normally about 40 mm down to dust. The proportions of the different sizes should be such that the smaller stones bind the larger ones together to stop them moving and these are bound together by the smaller onesl. The source of the stone varies widely according to what is the cheapest local supply and includes limestone, dolomite, and waste concrete and waste tarmac. It goes by various names; dolly, dolomite, crusher run, type 1, MOT type 1, road plannings, 40mm down  and many others. Ministry of transport type 1 is a type of subbase produced to stringent standards which while making it perfectly suitable for garden use it is a degree of over engineering. There is also type 2 and when I asked a technician at a quarry the difference compared to type 1 he just said “very little”!

 Dolomite has the disadvantage that it becomes saturated with water when you attempt to compact it there is a tendency for it to turn to something resembling plasticine in texture, although it hardens on drying out and road planning tend to become greasy when wet. Only hard stone should be used as even the hardest sandstone, for example, will rapidly breakdown to sand in use. Once spread subbase should be compacted with either a vibrating roller or plate BUT do not attempt to compact more than a 150mm deep layer at any one time.

Is Chelsea 2012 Still About Gardening?

Chelsea is over for another year and this year it was blessed with excellent weather. I haven’t been this year but I’ve watched the coverage on the television and while you miss some of the atmosphere the camera crews get far better access to the gardens than joe public. There is an element of garden snobbery that you HAVE TO GO TO CHELSEA! The reality is though it’s a very well orchestrated publicity show for gardening. Now that isn’t entirely a criticism; the RHS manages to get a great deal of publicity for gardening through this show with hours of T.V. coverage and acres of print which is all for the good of horticulture, but it is make believe. The days have gone when wealthy patrons bought a display garden and had it recreated in their own gardens. These days the gardens tend to be about promoting the sponsor and/or a theme. Some of these themes are very laudable but to what extend is promoting say caravanning connected to gardening? The truth is an awarding winning garden in the country’s premium garden show is guaranteed a lot of media coverage and not just in the UK.

This means that Chelsea gardens are now dominated by “Theme” gardens, created at great expense for corporate sponsors, which will all be vying for the judges’ and journalists’ eye. The cost of individual gardens is a closely guarded secret but it reckoned £250,000 is probably about average and some end up a £million plus. That’s very nice for the contractor and designers who make these gardens magically appear in the grounds of The Chelsea Hospital every year but just how relevant are these gardens to the average gardener.

I’m not saying don’t go, I believe everyone interested in gardening should go at least once, but not every year and don’t panic if you haven’t the time (or the money to spare). There will always be next year. And when you do get there expect to be in a big crowd with queues to see the display gardens and when you get to the front of them the view will be limited, but you can always watch them on T.V. when you get home! Once you’ve had your fill of them have a wander through the trade stands, there are a lot of them, but they have an important part to play in the financing of the show, and head for the marquees. This is where plants and nurseryman still hold sway and real horticulture is on show. This is the real heart of Chelsea Flower Show where stand after stand of nurseries of ALL sizes can exhibit. And if a plant catches your eye someone from the nursery, who knows the plant, will be on hand to explain it nature to you and provide you with a catalogue so you can purchase it and grow your own bit of Chelsea at home.

Bees need sound arguments not sound bites

A lot of publicity was given to the Friends of the Earth’s demonstration outside of Chelsea Flower Show this week highlighting the recent report commissioned by them on bees. The message of the demonstration was to get pesticides banned and they maintained their report supported this. Now peaceful demonstration is a fundamental right of everyone in this country, and quiet rightly, but are things as simple as banning pesticides going to aid bee populations recover? If you actually read the report, which credit to them, they have made available as a free download from their website things are far from that simple. There is a very complex interaction between food production and wildlife.  Now let’s get things clear, each generation has a moral as well as practical obligation to leave the world in as least as good a state as we inherited it – it is our children and grandchildren who will have to live on it after we have gone. The problem is that the environment is a very complex thing – I mean REALLY complicated! You think the instructions for the flat pack wardrobe are bad, that’s nothing! Thus the environment has this nasty habit of not reacting to our help as we expect it to. Not because it is just being difficult but because we really don’t understand it all that well. So say we ban pesticides, now what?

Of course we don’t actually know and that’s in part because the effects aren’t going to be just environmental. For one thing it’s going to have economic implications and economics is another very complex area we just don’t understand very well, just ask a European Central Banker! Whilst removing pesticides would mean the end of shelves of unblemished produce; people could be educated to accept that, the supermarkets managed to brainwash us all into believing the odd blemish was something dreadful. But we rely in a large part on pesticides to allow modern agriculture to provide us with the abundant supply of cheap food we find in our shops. The organic food we find in our shops, which is produced without pesticides, comes at a hefty additional cost which is at least in part the result of not using pesticides. Set this against the background of what has been described as an obesity time bomb caused by the bad diet of the developed world and we have a conflict. On the one hand the government what’s everyone eating more fruit and vegetables because of the cost to the NHS of our bad diet and the other we need to ensure the ecosystem and therefore ourselves survive long term.

Surely what is needed is a balanced measured approach which relies on known facts. The environmental lobby, as do all lobbies, has a habit of over simplifying things and relying on reducing things to sound bits. But the danger of this is you end up leaving people with the idea that there are simple solutions to very complex problems. Of cause what happens next is people try to implement the simple solutions and find all they end up with is an even more complex problem. So say you do just ban pesticides, what will happen next is the food industry, the environment, the retails and the consumers are all going to react to this and all these reactions are going to interact with one another. Whatever the outcome, and its not really possible to any more than guess what that will be, there is no guarantee the bees will come out the winners!

Hard Landscaping

This tends to be used, principally in professional horticulture, to refer to the none plant parts of a garden. So landscaping an area would be divided into either hard or soft landscaping. Generally this doesn’t include the soil and compost but where there is a lot of earth moving that could be included in hard landscaping and then the preparation of the ground for planting would be soft landscaping.