Garden Path Design and Planning
Paths in the garden
The actual layout of a path should take into consideration the time and amount of money which is available. The garden may be a new one, where paths are to be laid down for the first time, or an existing garden which is to be redesigned. If an old-world, or cottage garden effect is required, it is unlikely that a formal pattern will be suitable.
If the site is very undulating it maybe necessary to match paths with steps and terraces. In the smaller gardens the boldness of a length of path can be reduced or avoided if stepping stones are used, or if the monotony of the path is broken up by means of patterns or by the use of different materials.
Before any planning is contemplated, it is as well to have a good idea what is available in the way of materials.
The most popular material is concrete. Many gardeners mix this themselves by purchasing the basic ingredients, which are bags of cement, a load of sand and shingle or a load of mixed ballast. Some firms supply bags which contain all the necessary ingredients ready mixed and all you need to do is to tip the contents out, add water carefully and mix thoroughly. This is an expensive way of using concrete for large amounts of work, but ideal for small jobs and for patching.
Another popular paving material is crazy paving. This is available as York stone or broken paving stone. The best type of stone to use for its hard-wearing qualities is the former.
There are two thicknesses which are generally available, 3cm (11in) and
5cm (2in). The irregular outline of crazy paving breaks up the monotony of a plain surface to a path, and it is particularly suitable for the old-world or cottage type of garden.
Paths can be made from precast slabs which are available in a
wide range of sizes and colors. This enables you to plan and lay paths of outstanding design and appearance. You do not need a great deal of skill to produce these effects, provided you make quite sure that the foundations are secure. So versatile are these slabs that they can be used for any situation.
Mixtures of materials
By mixing materials it is possible to provide endless variations of path design. Old bricks can be used very effectively, especially if they are laid in herringbone fashion or in other unusual patterns. Cobble stones are available as a path-making material and are ideal for mixing with other materials. For example, a square of these pebbles can be framed by old bricks or paving slabs. With a little ingenuity and some artistic skill it is possible to use more than two materials. Various sizes of slab can be patterned or interset with pebbles or old bricks. It is important in this type of design to work it out carefully beforehand, either on paper or on the actual site itself by marking out the pattern with a pointed stick. Careful measurements must be made to make sure that all the designs fit accurately together for a completely professional look.
Cold asphalt compound
This provides yet another method of making paths in the garden. The process is extremely simple and as a long-term investment, compares very favorably in price with other ways of path making. The special material is available in 50kg sacks, together with special granite chippings which are used on the surface for decorative purposes. Two colors of compound are available, black and brown and a bag covers approximately 6m (20ft) square.
Paths can be made from granite chippings but the big drawback with these is that they pick up badly on the feet. They are also liable to drift towards the lower parts of the path if it is on a slope. This type of material is best used for a path or sweep under a bay window, for example, where little treading will be necessary.
Laying the pathway
Once the type of material has been decided upon, the preparations for laying should be carried out carefully and thoroughly. The route the path is to take must be marked out with pegs and line. If a curved or winding path is required, make sure that the curves are not acute or that the path weaves unduly. It is best to aim for gentle curves.
The amount of foundation preparation necessary will depend on several factors. The first is the type of soil in the garden. Light sandy ones need much more consolidation than the heavy clay types. Where there is any doubt about the firmness of the soil, plenty of small rubble must be rammed well into the foundation. Usually a depth of at least 15-25cm (6-9in) should be taken out and the bottom 13-20cm (5-8in) filled with rubble and rammed in well. Allowance must be made for the thickness of the paving material itself, also any bedding cement or mortar which may be required. In all calculations the finished level of the paving material should be just above soil level. This will do much to keep the path dry and will prevent the splash back of dirt or soil during periods of very heavy rain.
The width of a path should be considered and should not be under 60cm (2ft) for comfortable walking. It is as well to consider the wheelbase of trucks and wheelbarrows so that sufficient path width is allowed for them. Wider paths should be allocated for main routes to the busy parts of the garden where the wheelbarrow will be required a great deal. Areas around the greenhouse and frames are good examples.
There are several ways in which the paving materials can be laid. One is to place them on a 3cm (1in) layer of sifted soil, sand or ashes. Make sure that the bedding material is as level as possible and as each slab or brick is placed in position it should be tapped firm. It will be necessary to add or take away the bedding material to provide as level a surface as possible. Slight gaps can be left between slabs and filled in with the same material afterwards.
A slightly more secure way of bedding is to lay paving on the soil, sand or ashes and add under the center of each a trowel full of mortar which is made up of 1 part of cement to 5 parts of sand. It is a good idea to apply a little more mortar for the larger slabs of paving and this can be done by adding extra amounts of mortar to the four corners.
The best method is to apply about 2cm (1in) of mortar evenly over the soil, sand or ashes, spreading the mortar over the area one slab will occupy. Work should proceed in this way slab by slab until the site has been completely prepared. Afterwards, a drier mortar mix should be brushed into the joints, taking great care that any excess is removed from the surface of slabs to prevent discoloration.
Particular care is necessary when smaller paving material is laid, such as old bricks or pebbles. The latter can be set in the mortar mix so that approximately 1/4 of the base of each pebble is inserted and held in the concrete. The pebbles should be graded for size so that an even pattern is produced. It is advisable to have a ‘dummy run’ beforehand so that the pebbles can be arranged neatly and to size.
All paving set in mortar should be allowed to set thoroughly for 2 to 3 days before it is used. Work should not be carried out in very cold or frosty weather, but protection can be afforded from wet weather after work has been completed if large sheets of plastic material are placed over the paving.
The use of cold asphalt has revolutionised the art of path making for the garden. All that is required is the provision of a solid level foundation over which the preparation is raked to an even depth of about 1cm (1/4in). A light rolling is given and then the granite chippings which are usually provided, are scattered carefully over the surface and lightly rolled in. The path is ready for immediate use and becomes firmer the more it is walked on. For the first few days after laying it is wise to avoid the use of heavily laden wheelbarrows as their wheels tend to make a slight impression until the path has been made firmer by walking on it.
It is most useful, if not essential, to know how far materials will go when trying to estimate for layouts. The tables in this article provide a guide to the approximate quantities of most of the popular paving materials for given areas or lengths of path. Most materials can be obtained from local horticultural sundries shops, garden centers or builder’s merchants. A big advantage with the garden center is that many materials are on view and in some cases actually laid. This enables you to see the paths as they would be when completed. For making a path 3m (10ft) long see the table ‘Making a Path’.
As far as concrete paths are concerned, for the best possible results a suitable mixture of materials would be 1 part of cement, 2 parts of sand, 3 parts of shingle. If mixed ballast is preferred, the proportions should be 1 part of cement, 4 parts of mixed ballast. The aggregate size of the ballast should be graded from 18mm (3/4in) to 5mm (3/16-in). The dry materials should be mixed together thoroughly on a clean, smooth, hard surface before water is added. Water should be added in small amounts as mixing proceeds until the final mix has the consistency of thick, smooth porridge.
It is necessary to be able to calculate material quantities with reasonable accuracy for paths of various lengths, widths, thicknesses and for difficult mixes.
The appearance of a plain concrete path can be enhanced considerably if the surface is provided with a design while the material is still ‘green’ or wet. One simple method is to trace or score the surface lightly with a pointed stick or point of the trowel. The outline or false joins of paving slabs can be represented in this way, or crazy paving can be reproduced. Circles of different sizes can be lightly scored if round, empty tins or lids are pressed into the moist surface. A very pleasing rough cast finish can be provided if a stiff brush, such as an engineer’s wire brush or stiff yard broom, is carefully used on the concrete when it is practically dry. A little sharp sand lightly scattered on the surface and worked in with the brush will produce the same effect.
Coloring can play an important part in path construction and special coloring powders can be added to the cement as it is mixed. The only difficulty with this method is where several mixes of cement have to be made up during the work. It is difficult to ensure that every batch is of the same shade. Very thorough mixing is also required so that an even coloring is produced.
Once the concrete work has been completed it should be covered with damp sacking, hessian or plastic sheeting if it has been undertaken during hot weather. This will permit the concrete to dry or mature slowly and set thoroughly hard. Concrete should not be laid during very cold or frosty weather but in late autumn or spring the work can be carried out safely, provided some protection in the way of covering, is handy should there be light frosts.
All paths in a garden must be made at a gradient which is comfortable and convenient not only for walking unencumbered, but for pushing a wheelbarrow or transporting a mower from one part of the garden to another. Where the garden is on a slope it may be necessary to make steps to change the levels.
There are very few gardens where the operation of levelling is not required in some form or other. Perhaps most of the work is required in new gardens, especially where the ground is very uneven. Old-established ones often require some reorganization in places. There is a limit to the amount of levelling which should be carried out and before any work is started, it is most important that the site is carefully examined. This will enable you to plan your work so that the minimum amount of soil has to be moved during levelling operations.
If the garden has considerable differences in level, you would be wiser to work with the contours. This might involve the construction of sunken gardens, terraces, walling, pools, waterfalls and streams. It is surprising how very effective this type of design looks when incorporated in a difficult site. The most dramatic type of feature would be the construction of a series of waterfalls which finally empty into a pool at the lowest part of the garden.
The actual method of levelling is quite simple and there are several ways in which it can be undertaken. Sites which will need particular attention to levelling are those which are intended for the lawn and patio. To reduce work to the minimum, a place should be selected on the site for the required level which will not entail too much soil removal or addition to bring up the rest of the site level to this mark.
Once this has been decided upon, a peg should be driven in. From this master level peg, others are then inserted in the site and spaced apart according to the length of the level-board which is being used. This board should be a straight piece of plank, about 2.5cm (1in) thick and 2-3m (6-8ft) long. The level of these other pegs must be the same as that of the master one and this is checked at the start as each is inserted by placing one end of the board on the master peg and the other end on the peg which is being inserted. If a spirit-level is placed at the center and on the edge of the board, the peg can be driven into the ground until a perfect level is registered on the spirit-level.
Work proceeds by placing one end of the board on this newly inserted peg and a third peg is levelled in the same way. The whole site is dealt with in this fashion peg by peg. The work is completed by either adding to or excavating the soil on the site until the soil is
brought to the top of the pegs. In some cases it may be necessary to add a few barrow-loads of soil. A rake should be used to provide a good level finish.
Another method of levelling is by the use of boning rods. These are usually made of wood, 1M (3ft) in length, with a cross piece 38cm (15in) long at one end forming a ‘T’. There are three to a set. Boning rods are used in the following manner: insert a peg 3x3x25cm (1x1x9in) into the ground, leaving about 5cm (2in) protruding. This is the master peg, and should be driven in on the high or average high point of the plot. A second peg is knocked in, not more than 60cm (2ft) away, in the general direction to be sighted along. Check the level of these pegs by placing a spirit-level on the top bridging the two. A straight-edge board will be required if a short spirit-level is the only one available.
Using the two pegs, place a rod upright on each, and sight across the tops of these to the third one into the distance, held by a second person. By this means you are able to see by how much the third peg requires to be adjusted. Other sight lines may be set out from the master peg, by inserting another peg not more than 60cm (2ft) away, and in the direction of a third in the distance. This method can be used for most levelling purposes, but it is invaluable where the site is very rough and undulating, because sightings can be made over heaps of soil and debris, whereas some difficulty can be experienced using a straight-edge board and spirit level. After all pegs have been inserted it is time to review the whole levelling operation, for 2.5 (1in) taken off the general level all round at this stage will save money in material, soils etc, and of course labor. Whether the pegs are knocked further into the ground or marked with brightly colored paint, matters not, provided they are firm in the ground.
This type of levelling should be used where the site is very undulating, and will provide a rough first levelling of the soil. To produce a more accurate or even level, it will be necessary to use pegs, level-board and spirit-level as described i n the first part of this section.
No matter what type of levelling is used, it is very important that the good top soil should be kept to the top of the site. It is too easy a matter to bury good soil and finish up with a newly levelled site filled with infertile soil. Where necessary therefore, quantities of the good top soil must be carefully removed as deeply as is necessary and placed in convenient positions around the site for re-use later on. Where it is necessary to fill in with quantities of new soil this should be consolidated every 16cm (6in) in depth, by treading, or time should be allowed for it to settle down or consolidate before the site is made use of. Lighter types of soil can be trodden or given a light rolling for this purpose but only when they are in a dry, friable condition.