How to Build Rock Gardens

Here's a closer look at the plants I selected -- and why:

• Scotch moss (Sagina subulata 'Aurea') gives me a short plant with a touch of yellow.
• Daffodil (Narcissus) offers more yellow. This particular daffodil is a miniature, suitable for rock gardens.
• Wood spurge (Euphorbia amygdaloides 'Purpurea') provides yellow (its blooms) and red (its stems). It's a taller plant than the rest, giving the composition some depth.
• Offering more red is the foliage of low-growing hens and chicks (Sempervivum tectorum).
• Low-growing snow-in-summer (Cerastium tomentosum) gives me silver (its foliage) and, later, white (its blooms).
• The taller lamb's ear (Stachys byzantina) offers more silver foliage.
• My most striking white at present is provided by the flowers of candytuft (Iberis sempervirens 'Purity').

I focus on foliage in my rock garden design. Flowers come and go; but foliage serves as a backbone for a composition. Even so, this rock garden will look nicer in spring and early summer, when the plants are in bloom, than it will in late summer. That's a compromise I made. If I insist on colorful blooms throughout the summer, I can easily add the annual, portulaca, to the mix.

I made another compromise: with the Scotch moss, which is not drought-tolerant (one generally selects drought-tolerant specimens for rock gardens). This was a case where I sacrificed longevity for temporary "good looks."

The only plant in my rock garden grown more for its flower than its foliage is the daffodil. The relatively coarse textures of the lamb's ear, wood spurge and hens and chicks contrast well with the other plants, all of which have a more delicate foliage.

In Step 7 we begin planting....