Go-To-Perennials & GroundCover

This month I want to share a few of my favourite ‘go-to-plants’ that I frequently use as a garden designer in planting schemes. 

Every site and client is unique and as such calls for a bespoke, customised response to meet a site’s challenges and restraints such as climate, maintenance, aspect, budget as well as the client’s individual tastes. But admittedly there are certain botanical characters which I return to time and again, and I enjoy using either because they perform well, providing interest over a long period, are robust enough to cope with Exmoor’s cold, wet winters or simply bring me joy because of their floriferous nature.

Arguably one of the most important groups are  ground cover plants forming a dense, interesting tapestry of foliage, providing texture and pattern in the garden, essentially covering the soil to reduce weeds and soil erosion. In some ways this group is the most useful, forming a base layer of plants from which others emerge to add vertical height and interest across the seasons.

 Many ground cover plants by their innate nature are easy to propagate by division or rhizomes (underground stems that root easily) . So once they start to romp away and fill their allotted space,  maybe a bit  too successfully then it’s time to divide them. Ideally in spring or autumn (or a persistently wet summer) when the soil has both warmth and moisture, is the time to take a spade or trowel to these more boisterous botanical characters. Be bold. Identify bare, empty patches of ground, or new parts of the garden that might need cultivating even if they need clearing of less desirable plants first. Use these spaces to re-home your ‘offcuts’ or transplanted perennials. This window of the year provides us with a welcome opportunity to transform corners of the garden, overgrown beds and empty ones alike and it's always interesting to watch these new settlers colonising their new home. It’s also, importantly, a great way to save money and get plants for free. I’ve included a few favourite ground cover plants I below, all very good ‘doers’ and will certainly ‘earn their place’ in the garden ( an RHS Rosemoor garden manager term!)

Ground Cover for Foliage:

Brunnera macrophylla produces the most sumptuous silvery leaves that keep on giving, sometimes intially prone to slug damage but once they get going they offer the most beautiful heart shaped voluminous leaves. They are deciduous so will die back in winter to reappear in early spring. Their generous leaves provide good ground cover especially for cooler shadier sites, they bear blue or white forget-me-not like flowers in early spring ( but are much better behaved and more elegant). Once they have formed a substantial clump they can easily be lifted and split cleanly with a spade. 

Saxifraga x urbium or London Pride forms neat evergreen leafy rosettes bearing masses of airy cream flowers in late spring. It's name makes reference to the way this little succulent colonised bombed sites following the London Blitz and is symbolic of London's resilience. It is super as an edging plant in shade or sunshine, tolerant of most soils, it is  useful for underplanting and path edges, it will naturalise and colonise an area but is easy to control. 

Tiarella cordifolia is a wonderful ground cover for damp woodland or part shade. It has lobed palmate leaves with splashes of dark red and in all but the hardest winters behaves like a semi evergreen. This woodlander hails from damper regions of eastern North America, so prefers a moist soil. It’s common name foam flower refers to the plumes of starry delicate flowers borne from spring through summer that are very joyful. The name of the genus, Tiarella, derives from the Greek for ‘crown’ and ella which means small and refers to the fruit. It spreads readily by throwing out stolons, and can be divided in spring. Combines well with other woodlanders such as Hosta, Hellebore and ferns.

Euphorbia amygdaloides purpurea

Euphorbias or spurge are hardy evergreen perennials with whorls of leaves on upright sturdy stems, ranging in colour from glaucous green, to dark red depending on the species and cultivar. Many suit the middle of the border with their upright stems giving rise to zingy lime green flowers from spring onwards. Their flowers are made up of colourful showy bracts adding a strong architectural and textural quality to the border. They tolerate a wide range of soils and aspects, but their milky sap can be irritant; it was used as a purgative and is the source of the common name ‘spurge’. Adding height, texture and colour to any border they are so versatile and robust and diverse. I count on them as a go-to stalwart in the garden.

Geranium Anne Thompson

Hardy Geraniums: There must be a hardy Geranium for every occasion! They are vivacious and truly have a lust for life, rambling happily through the herbaceous border, hardy geraniums own their space, adding splashes of vivid colour across the growing season. Many will be equally as happy in the shade as the sunshine such as G. phaeum, a little taller and more stout than most. A new favourite to me this  year is one called Anne Thompson (right), very similar to Anne Folkard, the brightest of pinks with a dark eye in the centre of the flower, she will scramble happily through  the border.

Whilst Geranium pratense ‘Midnight Reiter’ has gorgeously dark divided leaves that contrast against blue purple flowers.

G. nodosum, similar to G. Wargrave pink has delicate pale pink flowers that light up a shady space. 

For the school garden I have been propagating G. macrorrhizum in attempt to cover the ground quickly. G. macrorrhizum is not the most aesthetically interesting but it is certainly a spreader and useful  if you want to fill a space, particularly woodland or difficult sites quite quickly, it can be useful as a sort of pioneer plant.

 Hardy geraniums are particularly easy to propagate with rhizomes that can be easily (and stealthily if it’s someone else's garden) plucked from the base of the plant to repot or plant and they will get away in no time. 

Nepeta: I use Nepeta quite a lot especially as an edging plant. It is a great if a little bit boisterous but the bees adore it and if you chop it back after its first flush of flowers in early-mid summer then it will produce a second bloom towards the end of summer. It’s foliage is wonderfully aromatic, similar to salvias, it does need space or you can select one of the more compact varieties such as N. racemosa ‘Little Titch’ or N x faassenii ‘Kit Cat’. But Nepeta responds well to being sheared back after flowering as soon as it starts to look a bit ropey. Looks super next to the zingy yellow mass of Alchemilla mollis flowers as they are both equally ferocious and abundant in their flowering. I often propagate Nepeta just by pulling or cutting a stem away from the base of the mother plant and potting this on or planting it straight away if the ground is moist. A great doer. Unstoppable. 

Astrantia with Nepeta flowers

Astrantia also known as Masterworts or Hattie’s Pincushion are fairly versatile, suiting either sunny or partly shadier woodland spots. Their happy profusion of starry pincushion flowers are enhanced by a ruff of bracts surrounding each flower. As clump formers they provide good groundcover especially when planted as a group and will split quite happily after a few years, or propagate from fresh seed at the end of summer. Deadhead regularly to encourage flowering into the early autumn, I think they look especially fabulous jostling next to Nepeta (catmint). Their flowers come in deep maroon burgundy red such as ‘Hadspen Blood, ‘Gill Richardson’ or ‘Claret’. But they range through soft pink including A. major ‘Roma’ to the white green flowers of A. major ‘Alba’ or A. ‘Star of Billion’.

Helenium ‘Sahin’s Early Flowerer’

Helenium autumnale: I am not pretending this is a ground cover plant - I am sneaking in and leaving you with my favourite flower of the season. I love Heleniums, I think it is their frilly petals combined with shuttlecock shape flowers and their hot burnt orange colours such as ‘ Sahin’s Early Flowerer’ and ‘Moerheim Beauty’. They range in colour through oranges to brilliant yellow such as H. ‘Butterpat’ and H. ‘Wyndley’ the latter being one of the shorter cultivars. They are great in a hot summer colour scheme especially planted in bold drifts and contrast handsomely against darker leaves such as those of Sambucus nigra or Physocarpus or dark leaved cannas. The genus hails from North America, Canada and Argentina and Chile. They do need staking, especially when grown on a heavier soil or in more exposed conditions but alternatively you could give them the Chelsea chop in May, which involves cutting all the growth back to ground level to create a bushier later flowering plant.

Named after the Greek goddess, Helen of Troy, daughter of Zeus who was reputed to be the most beautiful woman in the world. Their common name  sneezeweed derives from their former use as snuff, made from the dried leaves to stimulate sneezing believed to rid the body of evil spirits. Attractive to bees and pollinators they are relatively pest free although some moth and butterfly larvae feed off them. They prefer well drained soil and certainly want to be in the sun.