Rock Gardening and Peat Beds
Rock gardening is a specialised pursuit. Gardening on a peat bed is even more specialised, for it provides acidconditions suitable for only certain plants. Traditionally, peat beds were formed using large chunks of peat rather than rocks to build and outcrops. Today, however, it is rather difficult, and not really ecologically friendly, to obtain sizeable pieces of peat, so gardeners have turned to wooden alternatives. Railway sleepers are highly prized for making the retaining walls of a peat bed, but logs, stripped of bark and treated with suitable preservatives, are also widely used.
The rules for making a peat bed are different from the standard rock garden practice. First off, you should site the bed in a shady place since many peat-loving plants are woodland natives. They also like a moist soil, sodoes not have to be perfect. Finally, and most critically, peat-loving plants cannot abide a chalky soil, so even though you will be establishing an island of acidity, if the soil in your garden is naturally chalky, with high alkalinity, I’m afraid your peat bed will be doomed to failure. As you water the garden, the moisture will pass through the peat bed and into the foundation, only to be reabsorbed by the peat. The water will have become alkaline and, in time, the build-up will adversely affect the growing conditions. If your soil is neutral or only slightly alkaline, there should be no problem. Also, it is much better to water with rain water, rather than tap water.
To construct a peat bed, clear the site of any perennial weeds and fork it over. Lay the peat blocks just as you would stones for a rock garden. If you are using sleepers or wooden logs, you will need to attach them to upright supports. Fill the bed with a compost mix of moss peat, humus or well-rotted compost and acid-free grit in a ratio of 2:1:1. After planting, cover the bed with a wood-bark mulch.