Create a spectacular seasonal glow as your garden embraces the autumn months
Early autumn is the final hurrah for summer’s temporary stars, the tender plants whose show will be abruptly ended by the arrival of the first frosts.
For a brief moment the combination of mild days, recent rain and low, warm light can add up to golden scenes like this one, made all the more precious by its very impermanence. Dahlias and zinnias offer unrivalled early autumn firepower while pennisetum and the crinkly purple foliage of perilla bring texture, movement and a backcloth against which the last flowers can shine.
3 easy steps
STEP 1 - DESIGN YOUR BORDER
STEP 2 - CHOOSE THE RIGHT PLANTS
DAHLIA ‘SYLVIA’
Perfect balls of tightly rolled soft orange petals. Flowering July to the frosts, their strong stems make excellent cut flowers for your home. H: 90cm, S: 60cm.
PERILLA FRUTESCENS CRISPA
Purple shiso is a half-hardy annual herb grown for its fragrant, crinkled, purple leaves that looks great in ornamental schemes. H: 60cm, S: 45cm.
PENNISETUM ‘KARLEY ROSE’
Narrow arching leaves and from mid-summer swaying feathery panicles of pink-brown plumes. Not reliably hardy, treat as an annual. H&S: 90cm.
PENNISETUM ADVENA ‘RUBRUM’
Dramatic tender grass with burgundy-red foliage and purple panicles ageing to brown. Intolerant of cold and wet. H: 1.2m, S: 60cm.
ZINNIA PROFUSION SERIES
Bushy zinnia with single daisy-like flowers bred for disease resistance and no deadheading. Try ‘Profusion Apricot’ and ‘Profusion Orange’. H: 45cm, S: 60cm.
ZINNIA ELEGANS ‘BENARY’S GIANT ORANGE’
Fully double, glowing orange flowers on tall, sturdy stems. Half-hardy annual, brilliant flowers for cutting. H: 1.2m, S: 60cm.
STEP 3 - GET PLANTING
To get such a luxuriant display in a few short months, you require a sunny site and a fertile, moist but well-drained soil to help power the rapid growth for this modern bedding scheme. This autumn, break up compacted ground and clear the site of perennial weeds before working in lashings of well-rotted, weed-free organic matter. After planting, add a mulch to help keep down annual weeds, retain moisture and gradually improve soil structure.
1 Order the dahlias
Order dahlias now and you’ll be able to source whatever cultivar tickles your fancy. Specialist suppliers dispatch tubers from late winter onwards. If you have a frost-free greenhouse or sunny windowsill, it’s worth potting up tubers in March. The first shoots can be used to take basal cuttings that root quickly and flower in their first year.
Plant out after all risk of frost, working in further compost to the planting hole. Beware slug and snail damage to young shoots and add a short strong stake to loop around supporting string as the dahlias grow. In dry spells give them an occasional deep soak and deadhead every couple of days to keep the display going. A liquid fertiliser can help if you think the soil is on the poor side. After they’ve been blackened by frosts, either dig them up to store in old potting compost in the shed or leave them in the ground with the added protection of a dry mulch. The latter works well in all but the worst winters; just watch out for new shoots being eaten in spring.
2 Sow the perilla
Pick up perilla seed from veg or herb catalogues. Sow this half-hardy annual in trays under cover in April, barely covering the seed with compost and keep just moist until germination. Prick out and pot on before planting out 30cm apart after all risk of frost. Pinch out young plants to ensure a bushy display. Popular in Japanese cooking, the leaves have a flavour between cinnamon and mint and are most tender when young. Even the flowers are edible.
3 Sow the zinnias
Zinnias worship sunshine and warmth, so don’t sow them the second the sun comes out. Whether you’re sowing large ‘Benary’s Giant’ cultivars, or one of the small Profusion Series hybrids, leave sowing until mid-May under glass so that they can grow quickly without any check before going out into warm summer soil. They dislike root disturbance so use modules and plant out before they have the chance to become pot bound. Pinch back young plants and don’t crowd them – stressed plants are more prone to disease and damping off. If you don’t have propagation space, look out for young plug plants online or pot plants at your local nursery. Deadhead ‘Benary’s Giant’ types regularly but the smaller ‘Profusion Series’ produce a succession of flowers and don’t need deadheading.
4 Plant the pennisetum
These two pennisetums share the same intolerance to cold, wet conditions. Plant container-grown specimens from early June when the ground is warm and there’s no risk of frost, adding extra grit as well as compost. ‘Karley Rose’ is all grace with its wiry arching leaves and feathery cream plumes. It’s the hardier of the two and it’s worth leaving plants at the end of the season with top growth untouched and a dry protective mulch to see if they survive the winter. Don’t be too quick to give up on plants in spring as they’re slow into growth. ‘Hameln’ is a more robust cultivar. P. advena ‘Rubrum’ has broader leaves and a more sultry tropical appearance. Sadly, it isn’t hardy in the UK so treat as a centrepiece bedding plant, or lift plants and overwinter in a frost-free greenhouse or conservatory before they’re hit by the first frosts. Keep on the dry side then split and pot up into fresh compost once growth begins in spring.
MAKE THE DISPLAY LAST
WINTER: MISCANTHUS SINENSIS ‘KLEINE FONTÄNE’
Upright fountains of foliage and pink feathery flowers that bleach into winter, giving strong structural presence. H&S: 1.5m.
SPRING: EUPHORBIA EPITHYMOIDES ‘MAJOR’
Mound-forming perennial with lime-green flowers April to July, earning it the nickname of cushion spurge. H&S: 60cm.
SUMMER: CANNA ‘DURBAN’
Impressive paddle-shaped leaves striped in pink, orange and purple and striking, tall, orange flowers. H: 1.5m, S: 60cm.
AUTUMN: RICINUS COMMUNIS ‘IMPALA’
Large palmate purple-red foliage and red seedpods on fast-growing tender shrub, treated as an annual. Highly toxic. H&S: 1.5m.
