Shadowy characters
You can’t rely on the weather for a perfect patch so invest in shade-tolerant plants...
Despite having our fair share of rain through the summer months, this sort of rain doesn’t always dampen the soil.
In places where there is an overhead umbrella or canopy of leaves, moisture is spread too far from the roots of under-planting. I’ve got a ribbon of birch trees in my front garden, specimens I had used at a Chelsea Flower Show exhibit many years ago. The conditions below these trees, despite the downpours, could be described as a dust bowl.
No amount of rain seems to penetrate the ground and the normal species chosen for places of shade don’t thrive.
So if you’ve got some of these extreme conditions, which plants will do well during the summer months with a lack of moisture?
While many plants will grow happily in moist shade, the combination of poor light and dry soil is a real challenge.
This could be at the base of conifers, at the bottom of an old wall facing north or under the full canopy of deciduous or evergreen trees in the height of summer.
First of all, you can try to improve the soil by adding compost, soil conditioner or well-rotted manure. This will help its structure and retain any available moisture.
If you’re trying to plant beneath trees, you need to be aware of their shallow roots. Don’t panic if you sever one as it will probably regenerate, but do try to avoid doing so. The best way to do this is to use small plants you can tuck into the gaps between roots. As juvenile plants establish themselves, they will find their way around the root system.
Choose plants that are potted in a soil-based compost as peat compost dries out very quickly. Wait until early autumn before you plant so that new ones get a chance to settle in while there is some available moisture. Water in well and spread mulch between the plants.
You will also need to keep an eye on them in summer, and water if you think they are suffering. For best results, install some simple irrigation, such as laying down a seep hose which will leak water into the surrounding soil.
So what can you plant? You want to choose plants that can tolerate shade and drought, and that will colonise and form a moisture-retaining mat.
Epimediums are a good place to start – they have attractive foliage and in spring bear pretty delicate flowers. ‘Sulphureum’ has beautiful yellow flowers. Cut back dead foliage in spring, taking care not to snip off budding flowers.
Vincas or periwinkles are great at forming mats in dry conditions and have an abundance of white or mauve flowers in spring.
Ferns go beautifully with trees to form woodland-like gardens but you do need to be careful in your choice as many ferns require moisture.
However, some of our native evergreen ferns will do very well in dry shade, such as hart’s tongue fern, Asplenium scolopendrium, Polystichum setiferum, the soft shield fern and the common polypody Polypode vulgare.
You will still need to water them in until they get established, but they are very drought-tolerant once you get them established.
You sometimes see them growing out of walls as well so they’re not fussy about soil requirements.
Bulbs pair well with ferns, and I’ve found the dwarf daffodil ‘Tete a Tete’ and English bluebells very resilient in the dry soil under my birch trees. You could also try Cyclamen hederifolium here – not just for the bright flowers but also the attractive foliage – and some Anemone nemorosa bulbs this autumn (give them a soak before planting so they don’t go into the ground bone dry). I’d also recommend hardy geraniums, such as Geranium phaeum ‘Album’ which rapidly forms gentle mounds covered in white flowers to brighten up the shadiest spot.