Shallow flowerbed
Our house is built on a rocky base with only about four inches of soil before you hit rock. Are there any plants that will grow in shallow soil - preferably something perennial? This area is also in shade and tends to be dry most of the time.
Submitted by BHGPhotoContest

You are right to ask about the proper perennials for your conditions, but you have several problems to address before you plant a flourishing rock garden.



1.    Four inches of soil is too shallow for perennials to thrive. You need more soil, making berms or mini-beds where you can.

2.    If you need to bring in more rocks to make boundaries so that you can heap up more soil for small planting spots, make sure you bury them part of the way to keep them secure.

3.    Rock garden plants need perfect drainage. Mix in perlite with the planting soil.

4.    Your dry shade conditions limit the number of flowering perennials you can use. So be sure to mix in some annuals, like impatiens and coleus, but water them regularly and monitor them for droop so they don’t dry out.



That said, here is a short list of perennials for your Zone 8 rock garden:

Ceratostigma plumbaginoides (Dwarf plumbago)

Geranium sanguineum (Cranesbill)

Aquilegia (Columbine)

Phlox subulata

Myosotis scorpioides (Forget-me-not)

Dicentra eximia (Fringed Bleeding heart)

Heuchera x brizoides (Hybrid coral bells)

Asarum spp. (Wild ginger)

Answered by BHGgardenEditors