A well constructed rockery is an asset to any garden. It introduces height and shape in a natural way providing the ideal site for growing a whole range of miniature plants in the proper setting. Positioning a rock area can be difficult. If it can lean against a wall it will appear natural with the soil and rocks sloping to ground level. A free standing, conical mound of rock encrusted soil will appear contrived and artificial.
Avoid the walls of buildings as dampness will penetrate through to the inside. A stone built retaining or boundary wall is ideal. Choose your materials with care. The soil has to be weed free .If it is contaminated with perennial weed roots they will always end up under the largest rock, safe from attack. The rocks should be as large as possible. Decide on a local stone. Cotswold stone will look out of place where the local stone is basalt.
If alpine plants are to survive, the rockery must be free draining. Where soil is being mounded a layer of rubble below the soil will help. Mix sharp sand into the soil and cover the surface with coarse grit. Form a well drained scree bed by spreading crushed gravel on a slope of soil with rocks growing out of the surface.
A well constructed rockery should resemble a mountain scene in miniature. Most of the surface needs to be rock with the occasional pocket of soil for planting. Rocks with lines of strata, such as sandstone should be placed with the lines lying in the same direction. Tilt each rock so that its upper surface slopes back allowing water to run to the rear, off the rock to water the soil pocket it butts onto. Set each rock on a well compacted soil base to prevent it shifting if children clamber about the rockery.
If the pockets of soil are spaced there will be room for each plant to grow without crowding its neighbour. Cracks between rocks may be filled with soil and planted with small rooted cuttings of plants such as dianthus (pinks), helianthemum (rock rose) and thymus (thyme) which require little by way of moisture or nutrients.
When it comes to buying plants take care not to buy any which are rampant growing. There are many which appear to be dwarf but in the fullness of time prove you wrong by overpowering everything in their vicinity.
Clumps of dwarf bulbs including tulips,iris,and crocus provide colour in the winter months. Beware unsolicited gifts of unnamed plants from friends. They will almost certainly be quick spreading, ground cover plants which have smothered everything in their parh and are ready to perform in the same uncaring way for you. Who knows you may even get snow to cap it all. This line is simply to allow the ether to gobble up the last few words without causing grief!
