Plants for Dry Shade
Ryarsh Village Hall was full to capacity and a sea of eager, expectant faces greeted Kevin Hughes as he stepped forward. Somewhat sheepishly he said that he must start with a confession. We held our breath. Had he perhaps brought the wrong lecture? Worse still, no lecture? No, but the plant list, copies of which we now clutched like holy texts, had been printed from an uncorrected proof mistakenly sent to the printer, so was full of spelling mistakes. Furthermore, he was having considerable trouble getting his website up and running, so that wasnt currently operational either.
We relaxed visibly, and then we were off, trying to keep up with him on a voyage of discovery that contained many surprises and shattered not a few cherished illusions.
Firstly, dry shade should be regarded as an opportunity, rather than a disadvantage! There are, of course, various causes of dry shade: the soil itself could be very free draining, such as sand or gravel; it could be full of the roots of large trees; there could be buildings or other plants creating a dry, shady area. And it is a myth that digging in organic matter will improve moisture retention as, especially on acid soil, any moisture will quickly be taken up by large plant roots and whats left will become water repellent and actually deflect rain, thus compounding the problem. Even worse is mulching the surface with organic matter since this layer will merely absorb the moisture, or form a cap, and prevent it penetrating to where it is needed. A layer of leaf litter, on the other hand, is an excellent addition, as it will allow any moisture to pass through, it wont form a cap, it will suppress weeds and will rot down gradually to improve the soil.
Many plants we think of as drought tolerant, such as Mediterranean plants, only become so once established, so if youre prepared to nurture and water things for the first couple of years, they will often thrive in this most unlikely environment, especially spring-flowering plants, which will be getting the rain early in the season when they need it and will be dormant during the summer, when the tree canopy is creating shade and drought. Plants may not grow as big, but they may do surprisingly well. Helleborus argutifolius, for example, is much more resistant to black spot, while H. cyclophyllus and H. vesicarius always rotted, until Kevin tried planting them in heavy clay amongst the roots of oak trees, where they are now naturalising.
Cyclamen coum, which always tend to be planted more or less on the surface of the soil, in fact do much better if planted at a depth of at least two inches, and they should never be planted too close to C. hederifolium, which will quickly take over and smother them. Sarcococcas are ideal, being shade-tolerant anyway, but do need nurturing at first and feeding with tomato fertilizer. Try the Roy Lancaster introduction, Sarcococca orientalis. At Spinners, Kevin grew camellias in dry, gravelly shade, and hes even found a drought-tolerant willow, Salix hookeriana, from the US, which has the advantages of being good for wildlife and not seeding around prolifically. The list of suitable spring-flowering favourites seemed endless, as long as they received lots of TLC in the first couple of years. Even Erythroniums, which Id thought of as 'difficult' and requiring rich, moisture-retentive soil, will thrive in gravelly, rooty soils, so long as they can get established and are planted sufficiently deeply, about six inches for optimum flowering. Erythronium 'White Beauty'? Easy-peasy, says Kevin. But avoid the Chinese species of epimedium (except E. franchetii 'Brimstone Butterfly') as they are weakened by being defoliated, and brunnera, unless the soil is fairly fertile and watch out for slugs! Lilium pyrenaicum, which rots in moist, fertile soil, does well in the rooty gravel bank, as does L. monadelphum.
For a climber, try the May-flowering, mildew-resistant Lonicera sempervirens. For a small tree or shrub, the evergreen Magnolia laevifolia, floriferous, lemon-scented, then graced with a profusion of red berries. Or Daphniphyllum, a large, graceful shrub with red new growth and black berries in autumn. For acid soils, there are various rhododendrons, particularly those from the Eastern United States, such as R. prunifolium, in flower from May to August. For brilliant autumn colour, the fothergillas, especially F. gardenii 'Blue Mist' and F. x intermedia 'Blue Shadow', are hard to beat and, once established, they are truly drought resistant. Kevin had even found a hydrangea that will perform in dry, though not the driest, shade and was also frost-resistant: Hydrangea paniculata, 'Limelight' the recommended variety.
For autumn there are the sasanqua camellias, perfumed and of graceful habit, hollies, particularly Japanese hollies, the spindleberry, hardy bromeliads, Viola canadensis, colchicums, not our floppy native but those from Greece and Turkey, nerines and Cyclamen hederifolium. And Kevins favourite shrub, Salix bockii. Very attractive, growing only to about five feet, it flowers from August until the first frosts and is the Brad Pitt of the willow world because of its pulling power for bees and other insects! I was one of many, Im sure, who left the meeting feeling much more positive about the possibilities of the dry, shady area in the lee of my boundary hedge and determined to see it as an advantage, rather than a bane.
First published in the Kent Group Newsletter Winter 2008
and subsequently in Cornucopia Issue 25.
© Copyright for this article: Val Garrett
This article was taken from a copy of Cornucopia that was published in 2010. You could be reading these articles as they are published to a national audience, by subscribing to Cornucopia.