Rock Garden Ideas – Planning and Building a Rockery Garden

building a rockery garden

Planning and Building a Rockery Garden

Rock Garden Ideas for Laying Out

Once the possible site has been decided upon, mark it out as a rectangle slightly larger than required. Use rope or thick string to give the informal shape within the rectangle and try to imagine the third dimension, height. This will enable you to maintain a sense of proportion with the rest of the garden, if the rock garden is only one component in a larger plan.

Proportion is essentially the balance between length, depth and height, so that, when planted, the garden does not look like a mountain  or a molehill. Instead, the aim is to create a replica of a very small corner of any mountain with its plants. Any alterations to improve the growing conditions for alpines should be carried out now before the construction is started, not after. Make sure that you will have no difficulties getting to the site, both with construction materials now, and for future maintenance. The way to the site will need to be both clear and wide enough to receive the necessary stone and soil.

The speed of progress will vary considerably according to the accessibility of the site, the type of soil in the garden already, and the amount of help available. You will certainly need help, the amount depending on the size of stones to be handled. Teamwork is essential when dealing with the largest stones. Construction work is heavy and exhausting, and is best done in winter when conditions are cooler.

The Raw Materials

Once the planning decisions have been made it is time to order the stone, the soil, the first batch of alpine plants to grow between the stones, the tools and equipment necessary for the project, and to solicit the help of a few friends. It is advisable to order the stone well in advance of requirement, as delivery may take some time. When ordering direct from a quarry or through an agency, specify the approximate sizes required and seek their advice as to the quantity needed for your site. Ordering too many rather than too few pieces gives a much greater choice during construction. As stones vary considerably in their size/ weight ratio I will refrain from giving advice here as it could be misleading.

Soil usefully comes in bags or can be delivered by weight. Arrange for the soil to be delivered before the stone. If the soil is covered by empty plastic bags, an old tarpaulin or similar material, the stone can be unloaded onto the soil when it arrives. It is easier to tip a small load onto soft surfaces, rather than lift it  down onto hard ones. For larger loads, hire a tipper lorry to dump the stone straight onto the soil (if space allows). Otherwise order smaller loads which, though more expensive will be easier to deal with. Tipping causes very little or no damage, provided the first stones fall on a soft surface.

Construction Rock Garden Ideas

Reginald Farrer, an early alpine enthusiast, wrote in 1909 of the various disasters which have been given the title of a rock garden. He gave them descriptive names such as ‘Almond Pudding’ or ‘Devil’s Lapful’. These collections of stone fashioned together to form a mockery of mounds are fit only for weeds or plants so tolerant of extremes of wet and dry that they defy description! A successful rock garden should be a compromise between the wildness of a natural rocky habitat and the ordered human geometry imposed on some formal gardens; a showcase for some of the thousands of alpine plants available.

Rock Garden Ideas for the Stones

The structure of a brick wall with its regular layers gives a very good picture of how many of our rocks, particularly sandstones, were formed. A rock garden is laid in a similar way, except that the regular shaped bricks are replaced by the irregular-shaped stones, giving a series of single layered terraces of informal design, laid like those found in nature, with plants on the terraces and in between the stones.

For any shape of construction try to use large stones. They are more stable than a lot of small ones and look. much better. Choose stone which will suit the area and the pocket. Transport is very costly, so buy stone near home. Try to avoid rounded stones; they are difficult to bed in the ground and do not fit together well. There are exceptions though, for example, Westmorland limestone, which has no strata or line of formation and can be laid in any direction you choose, although fitting the pieces together will be rather like doing a jigsaw. It is a very heavy stone.

Sandstones, on the other hand, have definite strata, which may be hard to see at first but practice makes them easier to recognise. Always ask to be shown the direction of the strata when you buy the stone and lay it with the strata leaning gently back from horizontal, towards the centre of the site, (see figure 1). By laying a stone in the plane in which it was originally formed you can prevent frost action from splitting it and thus ruining an otherwise well-laid site. It will also make the presentation look more natural.

Some planting can be made between the stones during construction but never try to thrust plants in between stones after the construction is complete as this can damage the roots. Replacement might be very difficult so you should take all possible care to select good plants and treat them accordingly. Plant on the thinnest joints, see figure 16, so that the roots grow into the soil leaving the branches on the outside.

Equipment for Building a Rock Garden

You will not require many tools for laying stones but some are large. The number and sizes of obvious ones – spades, forks and shovels, depend on the size of the site. Do not be tempted to use a spade for a shovel, it takes too long! Gumboots are a must; consider safety gumboots with steel toecaps – there is no VAT on them! Many tools needed may be hired on a daily or weekly basis.

It is a good idea to use a sack truck, which, handled by three people, will carry up to 90 kg (4 cwt) quite easily. It should preferably have pneumatic tyres rather than solid ones. Make sure there is sufficient planking to run the truck over soft ground. The most readily available are scaffold planks, which you should make into a single line for each wheel supporting up to 45 kg (2 cwt). By doubling the thickness of the planks, up to 90 kg (4 cwt) can easily be supported by the pneumatic-tyred trucks. Stone over 90 kg will require four people and single planks 7.5 x 23cm (3 x 9in). You will also need crowbars which can be hired and rollers.

Moving the Stones to the Site

Arrange the planks and rollers as shown in figure 10. The rollers are made of solid metal rods, I metre (39 in) long by 20mm (3/4 in) thick. To prevent the planks moving when you are loading or unloading, cut four wooden wedges thicker than the rollers, and place two at each end, between the upper and lower planks.

rock gardens fig 10

To raise a stone you require two crowbars, pointed at one end and flat at the other, and some baulks of wood to act as fulcrums and blocks, see figure 11. Railway sleepers, cut to reduce their width by half, are ideal  for this purpose. The size of the crowbar depends on the size of the stone being moved: 35mm (1.5 in) by 1.5 metre (5 ft) long works well on loads of up to 90 kg (4 cwt); over that weight use heavier crowbars (about 9kg (40 lbs)).

rock gardens fig 11

To raise the stone onto a sack truck, see figure 12. Use the same technique to lift heavy stones to higher levels on the rock garden, and also onto planks and rollers. The rolling movement involved in this operation makes it ideal for moving stones short distances without a sack truck but I would suggest that on soft ground planks are used to stop the surrounding site becoming a quagmire and also to prevent the stone being accidentally buried.

Reverse the process for unloading, or turn the stone end-over-end over the handles of the truck as they rest on the ground, or on the first layer of stone laid, to give an immediate gain in height.

Another method of moving stone is by using paired rope slings. This  system requires four people to work it. The slings are made of nylon rope 1.5cm (1/2 in) thick, each one approximately 2 metres (6ft) long, spliced to themselves to form a ring. The slings can be used in two ways.

Firstly, to lift stone weighing up to 65kg by cradling it in the rings doubled up, two people lift the stone, while another two place timber under it in turn, until lifted to the required height. You still need one crowbar to get the slings under in the first place but this method saves time.

Secondly, the slings can be used to give a better grip when pulling stones along on rollers, see figure 13. Once the stone is lifted onto the planks, gently pull the planks along, lining up the rollers to enable the planks to be pulled round corners and carrying the rear planks and rollers to the front each time. Be careful not to topple the stone; use the crowbars to steady it, and to turn the top planks.

fig. 12 fig. 13 & fig. 14

Laying the Stones on the Site

When the stone is on the site ready for laying, try to disturb the ground as little as possible and do not hurry the operation at any stage; accidents can happen. Place the stones in their final position, using the same technique as before. To move a stone forward, see figure 14 (a) and (b).

Repeat the move making new holes for the crowbar so as not to disturb the ground too much. As each layer of stone is laid fill in the soil behind it by ramming in a barrow load, until the level is just below the top of the stone laid. This will hide the bases of the next layer of stones, without having to dig very much, if any, soil out. When a layer is completed, raise the soil level by 30mm (1 in) for every 30cm (1 ft) in length from one level to the next, so that the resulting hump allows for sinkage which, despite all the ramming, will occur.

The soil should cover the rear of all stones, so that none are exposed to show their size. This will give the impression of the stone running back into the ground as it does in nature. As each stone is laid stand at different points m the garden to see the effect. It is surprising how it can look well from one point and not from another.

Read more rock garden ideas.

17. October 2010 by Dave Pinkney
Categories: Gardening Ideas, Rockery Garden | Tags: , , , | Comments Off on Rock Garden Ideas – Planning and Building a Rockery Garden


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