Sharon Farnham at Headford Garden Design, Taunton, Somerset; expert in garden design and landscaping
Sharon Farnham at Headford Garden Design, Taunton, Somerset; expert in garden design and landscaping

Sharon Farnham at Headford Garden Design, Taunton, Somerset; expert in garden design and landscaping

Headford Garden Design, Taunton, Somerset; consultation, garden designs, project management, landscaping.

The nicest thing about the rain is that it always stops. Eventually. - Eeyore

Using 'black' plants in the border

January 2019
The Webmaster (he who makes all this IT wizardry possible), has politely requested an exposé on black and very dark plants, because the last blog was 'rather pinky, where are the Man Plants?'. So here we are with a piece on dark plants, for there is no such thing as a truly black flower. What we are really talking about is very dark purple, with a handful approaching a pretty convincing black.

Iris chrysographes

Dark flowers

For those of you wanting to include dark flowers in the garden, you can begin your search amongst the following genera: Tulipa, Clematis, Iris, Geranium, Penstemon and Salvia.
Plantaholics will spend many a happy hour searching online for all the gorgeous possibilities, and it would be impossible for me to list them all, but I have included a few lovelies for you to consider at the end of the article. I am going to confine this discussion to flowers, with a promise to cover foliage and stems in another piece.

Perhaps the bigger question is 'how on earth do we use very dark flowers in the garden?'. Let's face it, they can appear rather gloomy, and in low light they disappear altogether. In my opinion there are broadly three possible options.

Three options

Combine your 'blacks' with pale primrose yellows, to lift them out of the dark and provide a soft contrast. This is easy to achieve in spring, when sultry Tulips can be pitched amongst a carpet of common Primula vulgaris or the more desirable oxlip, Primula elatior.
The latter delightfully holds its clusters of pale yellow flowers on long stalks above the rosette of leaves. It was trendy at one time to create 'black and white' borders. Deep purple and white might be impressive at garden shows, but for me it is too harsh.

The second option is to indulge your Gothic tendencies and wallow in the atmospheric gloom by blending deep purple hues with a range of blues. The whole effect of this can be rather cool and recessive but this may be just the effect you are craving, and no doubt will appeal to The Webmaster, who is very occasionally known to expound the philosophies of Eeyore.
A cool, dark border can make a space appear bigger than it really is, and boundaries seem more distant, which can be useful in a small garden. Plant clumps of the tall bearded Iris 'Superstition' amongst a swathe of Geranium phaeum 'Blue Shadow', finished off with an edging of Ajuga reptans Atropurpurea.

Iris 'Superstition' Geranium phaeum

Finally, for a lively sparkling effect, deep purple will really pop against bright yellowy-oranges. Try these together in a well drained sunny border:

  • Penstemon 'Midnight'
  • Penstemon 'Raven'
  • Salvia nemorosa 'Caradonna'
  • Salvia nemorosa 'Lubecca'
  • Helenium 'Sahin's Early Flowerer'
  • Echinacea 'Tomato Soup'

Penstemon 'Midnight' Salvia nemerosa 'Caradonna' Echinacea 'Tom Soup'

You could add an orange Crocosmia, but I never actually recommend it, as it can take over. All of these plants flower over a long period.

Plant profiles

Penstemon 'Midnight'

A semi-evergreen perennial, with tubular to bell-shaped deep purple-blue flowers flushed violet with a white throat produced throughout summer. This hard-working plant has the added appeal of dark purple stems to 70cm high, forming an upright clump.

Iris 'Superstition'

A bearded iris with sultry, purple-black flowers from April to May and greyish green, sword-like leaves. It looks stunning planted in drifts in a well-drained, sunny border, to harmonise with other blue and purple flowers, or to provide a dramatic accent among paler flowers.
Bearded Irises must be planted shallowly with the upper part of the rhizome showing on the surface of the soil. After planting, trim back the top third of the leaves to prevent wind-rock. In exposed areas stake with bamboo canes in early spring. Remove the stems after flowering from the base as this will concentrate the plant's energy into producing new rhizomes. Divide and replant rhizomes about every three years.

Iris chrysographes

This a serious Man Plant - dramatic, indigo-violet, almost black flowers appear in May and June above strap-like grey-green leaves. A clump-forming, beardless iris, related to the moisture-loving Siberian iris, makes a striking feature in a sunny, moist area of the garden, or beside water.

Salvia nemorosa 'Caradonna'

Many of the darkest flowered Salvias, like 'Amistad', are a little on the tender side, so I haven't recommended them as reliable garden plants. 'Caradonna' is a perennial cultivar with upright racemes of violet- purple flowers through the summer above narrow, rough, grey-green leaves. Not really a very dark flower, but it helps to lift the summer border to another level when mixed with the darker plants listed above.

Geranium phaeum

The species G. phaeum is an erect, clump-forming perennial with lobed leaves often with brownish markings, and flat, outward-facing delicate dusky purple flowers in late spring and early summer. A gentle plant for shaded areas. There are some good cultivars worth finding - 'Lily Lovell' has larger flowers, and 'Samobor' has lobed leaves bearing a striking deep brownish-purple zone, and slightly nodding maroon flowers.

Clematis 'Romantika' (clematis group 3)

How about a climber to complete the set. This has very deep purple flowers with contrasting pale yellow stamens. The blooms are produced from July to September and it looks particularly attractive when planted against a light background or growing through shrubs with light green foliage.
Prune back in early spring to a pair of strong buds about 20cm above ground level. Position in full sun or partial shade, in fertile, well-drained, neutral soil.