Hard-working shade plants

Gardeners can have it made in a wide swath of their shade by selecting plants that spread on their own and need little maintenance.

Beds typically look their best when layered with plants of varying heights, color and structure, but one large tree can cast a big enough shadow to intimidate any gardener who might be deterred by the expense of trying to dress up such an area.

If you're patient, you can save money and let the plants do the work.

Before we get to the plants, though, you'll need to do some surveying. If your shady area is under an established tree and you've been covering the area with mulch instead of trying to grow grass, you may be ready to advance directly to Go. Typically, you can begin planting perennials by mid-May, but keep an eye on the 10-day forecast.

If you've got a hardpan surface interrupted by lots of surface tree roots, you're facing a longer-term project to improve your soil. Simply adding several inches of a garden-ready mix to the area may seem to be an easy solution, but that can compromise your tree's health by smothering its surface roots.

Opt, instead, for spreading 2 to 3 inches of organic matter — mulch or compost, or both — as the weather starts to warm. To accelerate the process, top-dress the area again later in the season. Then let nature do its thing.

Depending on your native soil, you might be able to start planting in Year 2, picking several plants of the same type and starting them in groupings. As you keep adding organic matter each year, the soil will become more and more hospitable, allowing these spreaders eventually to cover more space on their own.

While you're waiting for the worms and microorganisms to convert your mulch into garden goodness, consider enhancing the shady area with a focal point — lay a pathway to a bench surrounded by containers with shade annuals. Similar elements include yard art, decorative lights, bird feeders or a water feature.

Now let's talk plants. As mentioned, these will naturalize over time while typically not overwhelming their neighbors. All are hardy to at least Zone 4, some to Zone 3.

These are personal favorites because they just grow, with not a lot of attention:

Brunnera macrophylla (Siberian bugloss): Over the years, hybridizers have developed several eye-candy cultivars, but the straight species Brunnera is a standout nonetheless, a plant I've populated in multiple beds. It brings a spray of forget-me-not-style blue flowers in early spring. As their seeds drop, several new plants will develop from year to year. The distinctive crinkled foliage holds up well.

Chelone lyonii or Chelone obliqua (pink turtlehead): This upright 3-footer has attractive dark green foliage and spreads by rhizomes. In August and September, its pink flowers resemble a turtle's head.

Stylophorum diphyllum (Celandine poppy): This wildflower has a bright yellow flower in early spring and will rebloom into June. It handles heavy shade and wet conditions and can go dormant in dry conditions, although one plant I have growing in afternoon sun actually holds up well.

Polygonatum odoratum 'Variegatum' (Solomon's seal): The Perennial Plant Association's 2013 Perennial Plant of the Year, its unbranched stems have an arched shape with distinctive variegated foliage and tiny bell-shaped flowers in May. Spreads by rhizomes. Excels in both wet and drought conditions, and the foliage turns a pale yellow in the fall.

Pachysandra terminalis: This shrubby evergreen ground cover spreads slowly by rhizomes into a dark green carpet. Though it's best in organically rich soil, it also holds up well in less-than-optimal conditions.

Others plants to consider: anemone, columbine, cranesbill geranium, ajuga and Cardinal flower lobelia.

A word about water and nutrients: Keep in mind that a tree sucks up a lot of both, so be thinking of your shallow-rooted perennials come the dog days of July and August. Setting up a network of soaker hoses is a timesaver and is the preferred irrigation method over less efficient yard sprinklers.