How to plant a dry garden
To prepare a dry garden bed, we recommend planting on top of the existing soil level. We use recycled construction material (broken bricks, tiles, and concrete) to raise the planting foundation as high as possible (see illustration below). On top of this, we prefer to add bull rock (2"-4" in diameter) or pea gravel works almost as well.
When planted high and dry, most desert plants can thrive in areas of high rainfall and low temperatures-even as far north as Boston. We plant in a soil mixture that consists of two parts ground pine bark, one part coarse concrete sand, and one part pea gravel.
To the soil mix we often add a well balanced organic fertilizer. Follow label directions for application rates. If the native soil is extremely acid the addition of a horticultural lime can also be of great benefit. Top-dressing the surface around each plant with pea gravel or crushed granite helps to prevent weeds, shades the roots in summer, and collects heat during winter.