It can be a real challenge to establish plants under the canopy of large trees with shade and lack of moisture being real problems. Whether your tree is deciduous or evergreen will make a difference as will the height of the canopy, the higher the better so you may wish to raise it with some gentle pruning. However there are a number of plants and bulbs that will tolerate such conditions and thrive.
First of the year would have to be the Hellebores (Christmas rose) with their elegant and almost unexpected flowers in late winter and early spring.
Whatever you choose it’s important not to disturb or damage the roots of the tree so plant carefully. Probe the ground to identify pockets of soil and use small young plants that will establish quickly.
If the tree canopy is quite high, then plants that are perfect for spring include bluebells, bergenia (elephant’s ears), lily of the valley, Brunnera and hardy cyclamen which will all establish and put on a good show even quite close to the trunk. Tall spires of Foxgloves are another great choice as they thrive in dappled shade and often self-seed as will varieties of Viola odorata, the Sweet Violet.
Ground covering plants like the many different flowering Epimediums tolerate dry shade as do the evergreen Vincas (periwinkle) which spread quickly and can be relied upon to give a good show all year round including soft blue flowers in late spring.
Perennials like the charming Alchemilla Mollis (lady’s mantle) with its frothy lime green flowers in summer and bright green leaves which catch droplets of water that look like quicksilver. Also the cranesbill geraniums, hay scented Sweet Woodruff or the excellent Solomon’s seal with its pretty bell shape flowers in spring.
Small shrubs such as Rose of Sharon (Hypericum calycinum), Sarcococca hookeriana and Viburnum Davidii have both flowers and then berries so offer year round interest
Some ferns and grasses will tolerate dry shade as will climbers like the Chocolate vine (Akebia quintata), Clematis montana or Hydraenga seemanii.
Perfect in the autumn are Japanese Anemones with their beautiful pink or white flowers, Cyclamen hederifolium and some of the Sedums which will tolerate shade.
This is just a small selection of suitable plants so actually it’s not such a challenge to have a year round display of colour under a tree with these and so many more to choose from!