With autumn comes dull, misty days and grey skies, and with the change of season a change of flower colour is warranted. Although strong, saturated colours look good in summer sun, they can appear jarring and drab under autumn’s diffuse light. A better approach is to use soft pastel shades: pink, blue, purple and white flowers, and combine them with misty blue-grey and silver foliage. Such gentle colours come into their own in the watery light of late September.
Suitable autumn-flowering perennials include many Sedums, Asters, Japanese anemones, Nerines and autumn Crocus. While these are good on their own, pair them with silver foliage plants, and you will create a misty-grey scheme that positively glows on even the dullest day.
For silver foliage, the mugworts are especially effective. I like Artemisia schmidtiana ‘nana’ (featured above) which forms small clouds of grey at the front of the border or between taller plants. The other silver plant, above, is Snow in Summer (Cerastium tomentosum) which flowered earlier in the year. Once finished, I cut back the spent flower stems to encourage lots of new, silver foliage that shows off the autumn sedums.
In other parts of my garden, silver-grey mounds of rock rose (helianthemum ‘Wisely pink’) serve the same role, as do Curry plant (Helichrysum italicum) and Lambs ear (Stachys byzantina). Late-flowering perennials such as Lavender and Russian sage can do double duty, providing pastel flowers above silver-grey foliage.
Some sedums provide good leaf colour: glaucous green or deep plum purple, depending on the variety. The latter contrast nicely with adjacent silver-grey foliage. Many modern shrub roses continue to flower well into autumn, so can be used to good effect as backing plants.
Below are some of the plants that are flowering in my garden in late September this year. Hopefully, you can find something here to inspire you…
- Hidcote Lavender
While many lavenders finish flowering earlier in the year, Lavandula ‘Hidcote’ will continue right up to October, attracting bees and pollinators throughout. Silver-grey foliage adds to the misty theme.
- Garlic Chives
Allium tuberosum flowers from July until late September. This clump-forming onion holds its 2in flower heads in white balls on 2ft stems. Another bee magnet. Cut off spent flowers to prevent unwanted seeding.
- Allium senescens glaucum
Another late-flowering onion which produces soft pink flowers held 12 inches high from August to September. The leaves are interesting too: flattened, grey-green, twisting and curling in neat clumps.
- Japanese anemone ‘Honorine Jobert’
A magnificent perennial, holding its pure white flowers three to four feet high. One of the best late-season flowers. Pink and mauve, single and double varieties are available. Take care: they can spread rapidly in good soil.
- Society Garlic
Flowering continuously since spring, Tulbaghia violacia just doesn’t know when to stop. Loosely spherical heads of mauve-pink flowers held 2ft high. Cautiously hardy if grown in free-drained soil (mine are in gritty raised beds).
- Russian Sage
The smokey grey-white stems of Perovskia ‘Little spire’ rise to 3ft carrying wafty stems of hazy blue flower throughout September. Pollinators love it. Can flop, so site it where it gets some support.
There are many silver-foliage plants that work well in an autumn pastel planting: Lambs ears, Snow in summer, Curry plant and many Artemisias too. Artemisia alba canescens is a favourite, growing to 3ft with fine curly leaves and silver flower bobbles. Stems find their way between other plants.
- Hosta flowers
Although Hostas are primarily grown for their leaves, they also produce flowers. The flowers of Hosta ‘Purple heart’ are a soft mauve above green leaves, enhanced by deep purple leaf ribs and flower stems. Good in part shade.
- White flag lily
Hesperanthera coccina ‘Alba’ (previously Schizostylis) comes into flower towards the end of September. The stems are 18 inches long, tending to be rather lax, but the flowers are exquisite. Pink and red forms are also available.
- Michaelmas daisies
There are hundreds of Asters to choose from, all of which flower in the autumn. Aster x frikartii ‘Mönch’ is one of the most rewarding as it comes into flower so much earlier than most (June/July). Another pollinator magnet.
- Lily turf
One for part-shade. Lily turf forms grassy evergreen clumps, from which rise curious dense flower spikes which (depending on the variety) can be blue, violet, mauve or even white.