Moraine Or Scree Gardens

For most alpine plants they are best grown in a deep, rich, well drained soil; and while perfect drainage is required they also like plenty of moisture. There is a fine balance to getting this right. So it is important to provide growing medium that is gritty and well drained. A perfectly good garden can be constructed on a flat site as long as the drainage is good and that water doesn’t lie stagnant underneath. The aspect is also important and a garden that is facing south is most favorable and will allow you to grow a greater variety of plants but if this is not possible then one facing east or west is ok. Also using carefully placed rocks to shade plants will help and can be used in the main construction of the garden.

When constructing a garden for alpine plants the base should consist of a free draining rubbly material such as 40-65mm crushed (AP40 or AP65) stone at a depth of about 15cm.

Over that should be a layer of 10-12mm chip. The purpose of this layer is to bind the coarse material and prevent the finer particles of the scree mixture filtering down and blocking drainage.

Next comes the first layer of scree mixture which should be about 15-20cm deep and made from a mixture as follows: 1.5 part 10-12mm stone chip, 1.5 part peat or leaf mould

Next comes a layer of a coarser scree mixture which should be about 10-15cm deep and made from a mixture as follows: 1 part course river sand, 1 part quarry mix*, 1.5 part 10-12mm stone chip, 1 part peat or leaf mould.

* quarry mix is crushed aggregate containing a mixture of stones 15-30mm in size.

Once planted a stone chip can be used as a final layer.

This cross-section shows the construction of a scree garden suitable for alpine plants. The use of rocks placed in the scree will provide structure for the garden and shade for plants that need it.