Alpine or Rock Garden Design

by Duncan McAlpine

So, you want to build a rock or an alpine garden but you don't know what type of rock to get? Practically any kind of rock will do for the construction. If you can find it, weathered limestone is considered one of the best, while the round field boulders or river gravel is the least desirable. The Beginner's commonest faults in constructing a rock garden is the tendency to place stones on the end in a way that it will never seem natural or they align them formally at regular intervals which is equally unnatural. Spend a little time understanding the how natural outcropping looks before construction. Go visit a mountain a get a breath of fresh air and see how a natural outcropping might look. If your lazy, read a rock garden book and observe the pictures.

When a site is selected and its boundaries are marked off, the area should be dug out to a depth of at least a foot or more especially in low ground. One condition that alpine plants almost invariably require is good drainage. The exvation should be filled a little more than half full with broken stone, shattered bricks or terra-cotta or a coarse gravel; this material may be piled a little higher in the spots where the final constructions will be high. Next add a layer of sand, gravel or finer gravel which has been washed with water. Remembers drainage is a requirement.

Now that the drainage has been provided, throw a layer of soil over the gravel and wash it with water. The soil will filter its way through to the bottom. This is important thought out the construction as it prevents any possibility of air pockets which roots might stray and in addition it reduces to a minimum future settling which will change the outlook of the garden. Next lay an irregular rim of rock around the edge of the area, some stones being almost flush with the ground and others rising well above it. Fill this enclosure with the soil mixture and wash it again.

Now lets form another layer in the same way sinking all large rocks firmly so that they do not move when stepped on. Remember that irregularity in the width and height of the levels is essentials and that the grain of the rock should tend to run inwards. The leveling process may be continued until the desired height and shape is reached.

Once the constructions has been completed, the soil should be plentifully scattered over with limestone or other stone chips. Gravel will serve the same purpose which is to slow down the evaporation of moisture and keeping the foliage off the ground.

Now you have built your first rock garden, you need to select the correct plants to thrive in this type of environment. The nursery and plant links are good places to start. Now that you have finished a rock garden, it is time to build a "Scree or Moraine garden".

Are you ready to become a big time rock gardener? Have you joined any Rock Garden Societies? Now its time to learn how to make a Scree garden.

A Scree in nature is a mass of rocks, stones, gravel and a small about of silt which is deposited at a base of a rocky hillside or reminisce of a glacier which is a Moraine. The proportion of soil in this debris is negligible but certain plants do survive here. A moraine is usually on a sunny slope that is watered from underneath as well as the manner of its deposit is what distinguishes the moraine from the scree, which is the mass of broken rock at the base of a cliff, formed by the accumulation of fragments torn loose from above by frosts and rock slides. In other words, the scree is a dry moraine as far as the rock garden is concerned .

Many gardeners prefer to have a sloping concrete basin a foot or so below the surface as a foundation for the moraine, but this is not really necessary unless the ground below is very sandy and likely to drain off the supply of moisture too rapidly. Other wise the foundation of drainage is the same as addrssed for the rock garden. Instead of building up with the regular soil mixture, use one part of that to four or more parts of gravel, sand and broken stone. The moraine feature should be a gentle slope in a valley of the rock garden with cliffs on each side and higher construction at the top.

The underground watering is supplied in various ways. If the concrete foundation is used, a trickle of water in at the top is sufficient. Otherwise, one of the best methods is to run a perforated pipe up the middle of the valley a few inches below the surface. This pipe should be fitted with a valve so that only a very little water will flow, other wise the moraine will turn into a swamp. The water may be turned off entirely in wet weather and of course in the winter.


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