Under-Planting a Large Tree
Mature trees bring beauty and
a sense of history to our outdoor spaces.
All too often though, the dense canopies and aggressive root systems of these trees create daunting patches of dry, deep shade that defy even expert gardeners. But don’t despair! With a bit of research and
extra compost these barren areas can be transformed into another lush corner of the garden.
Sword Fern, Polystichum munitum — Commonly seen in redwood forests, this evergreen fern will reach 2-4 feet tall and wide at maturity. It’s leathery dark green leaves provide a sense of height and structure.
Epimedium — A shallow rooted ground cover that looks delicate but is tough as nails and highly adaptable. Heart shaped leaves are suspended by dark wiry stems.
Black Mondo Grass, Ophiopogon japonica “Nigra” — A low growing (6-8 inches tall) evergreen ground cover with striking black grass-like foliage. It’s a slow spreader but it dramatic color makes it a perfect partner for just about any plant.
Mature trees are water and nutrient hogs and the soil below them is often dry, depleted and chock-full of roots. These roots are often found in the first foot of soil, making it difficult for new plants to establish themselves. Heavily needled evergreen trees create an additional problem because their dense foliage blocks much needed winter moisture from reaching the ground directly below them. To contend with these trying conditions, look for plants that are shallow rooted and tolerant of drought and shade conditions. Believe it or not, there are plenty of beautiful plants that fit the bill!
Substitutes also exist, including Native Bleeding Heart (Dicentra formosa), Helleborus, Lenten Rose (Helleborus orientalis), Lilyturf (Liriope spicata), Lamium, Ajuga, Saxifraga stolonifera, Pachysandra terminalis, Salal (Gaultheria shallon), Wood Sorrel (Oxalis oregana) and Spring bulbs.
Image credits to Xera Plants
New growth on Epimedium may take on a mottled pink color in spring, which will turn to a lush green in summer and some varieties take on a lovely bronze hue in the fall. Fragile pale yellow, pink or red flowers emerge in April-May to hover above the foliage. Some species are evergreen, but even the deciduous species will hold their leaves late into the fall. Most varieties grow between 6-12 inches tall and spread slow-to-moderately fast.