Autumn flowers are the plants that are in bloom from September to November, when most summer flowers have given up. The differences between them are large. Heather and Michaelmas daisies cope with 20 degrees below zero, while dahlias and zinnias are wiped out by the first frosty night. Here we go through which species flower when, how much frost each one tolerates, and what you need to sow or plant as early as spring to have flowers in October.
Buying plants or sowing your own
We sell seeds, bulbs and tubers, not ready-grown plants, so it is only honest to start there. Cushion chrysanthemums, heather, Erica and cyclamen are almost always bought as ready-grown plants in August or September. Michaelmas daisies, showy stonecrop and Japanese anemones are sold as potted perennials and flower from their first autumn.
What gives you autumn flowers from a seed packet the same year is flowers that start in July and carry on until the frost takes them: zinnia, China aster, cosmos and Caucasian scabious. China asters, also sold as summer asters, flower from August to October and are sown indoors in March or April under 0.5 cm of compost, see the article on growing summer asters. Dahlias grown from tubers belong here too. They flower from mid-July until the first frosty night blackens the leaves.
Flowering time and frost tolerance by species
The figures apply to established plants in a border. In a pot the cold reaches in from all sides, so expect a smaller margin there.
| Plant | Flowers | Tolerates roughly | Sow or buy |
|---|---|---|---|
| Heather (Calluna vulgaris) | August to October, late varieties into November | Below -20 degrees, evergreen | Plant |
| Michaelmas daisy (Symphyotrichum) | September to October | Down to -20 degrees | Plant |
| Showy stonecrop (Hylotelephium spectabile) | August until the frost, the flower heads stay standing | -15 degrees once established | Plant |
| Japanese anemone (Anemone hupehensis) | August to October | Hardy in most of the UK and northern Europe | Plant |
| Caucasian scabious (Scabiosa caucasica) | June to October | Perennial, flowers until the frost | Seed, sown February to April |
| Cushion chrysanthemum (Chrysanthemum x morifolium) | September to November | About -5 degrees, rarely overwinters outdoors | Plant |
| China aster (Callistephus chinensis) | August to October | Annual, only a light night frost | Seed, sown March to April |
| Zinnia (Zinnia elegans) | July to September, into October if the frost holds off | No frost | Seed, sown late April to May |
| Dahlia | July until the first frosty night | No frost, the leaves turn black | Tuber, planted in May |
| Graceful heath (Erica gracilis) | September until the frost takes it | No frost | Plant |
| Cyclamen (Cyclamen persicum) | In the shops from August, flowers autumn and winter | No frost, bring indoors below 0 degrees | Plant |
Autumn flowers out in the border
The perennials do the work in the border. Michaelmas daisies grow 20 cm to 2 m depending on the variety, Japanese anemones 50-100 cm and showy stonecrop about 45 cm, so the three cover both the back and the front. Plant them in spring or early autumn, Japanese anemones no later than September. Keep 40-50 cm between Japanese anemones and 20-30 cm between heather plants. Winter wet damages Michaelmas daisies more than the cold does, so choose a spot where the water drains away.
In front of the perennials, let the summer flowers stand. Zinnias and cosmos sown in spring flower into October if the frost holds off, and Caucasian scabious Fama White gives white flowers on 50 cm stems from June right through to October. Fountain grass (Pennisetum) and other ornamental grasses send up plumes from late summer that stay standing through the winter.
Autumn flowers in pots
The pot is the place for the bought plants: cushion chrysanthemums, heather, Erica and cyclamen. The compost in a pot gets colder than the soil in a border because the cold reaches in from all sides. Stand the pot on two bricks so that the drainage hole stays open.
Cushion chrysanthemum: buy plants with more buds than open flowers, so you get the whole display at home. Plant it at the same depth as in the nursery pot and water when the compost is dry a few centimetres down. More in the article on growing cushion chrysanthemums.
Heather: wants acid soil, so mix in ericaceous compost. It dries out quickly in a pot, so feel the compost every other day and water until the ground freezes.
Erica and cyclamen: the most colourful of all, but neither tolerates frost. Bring cyclamen indoors when the nights drop below 0 degrees and expect the Erica to be replaced after the first frosty nights.
Spring bulbs underneath: plant tulips, daffodils and crocuses in the same pot between September and December, and it flowers again from February. How the layers go in is explained in the article on autumn planting in pots.
Autumn flowers that tolerate frost
Rank the plants by how much cold they cope with and the choice becomes simple. Heather and Michaelmas daisies sit at the top with 20 degrees below zero. Showy stonecrop copes with 15 once established. Cushion chrysanthemums cope with a light night frost down to about 5 degrees below zero but rarely overwinter outdoors, so bring the pot in when flowering is over and keep it at 5-10 degrees. Dahlias, zinnias, Erica and cyclamen tolerate no frost at all.
The rule we use: choose by frost tolerance first and colour second. If the pot by the door is to look good until December, choose heather. If you want the most colour in September and October, choose a cushion chrysanthemum and replace it when it has finished flowering.
Year plan for autumn flowering
Most of what flowers in October is decided between February and June.
February to April: sow Caucasian scabious indoors. The seeds are sown shallowly and germinate in 10-20 days. China asters are sown in March or April under 0.5 cm of compost.
March to April: start dahlia tubers in pots, 10 cm below the surface, in a light and cool place. Water sparingly until the shoots show.
Late April to May: sow zinnias. They tolerate no cold, so do not sow any earlier.
Late May to early June: plant out dahlias, zinnias and asters once the risk of frost has passed. Cover with fleece on cold nights.
August to September: plant Michaelmas daisies, showy stonecrop and Japanese anemones. Buy cushion chrysanthemums and heather in bud.
September to December: plant bulbs for tulips, daffodils and crocuses in borders and pots for flowers from February to June.
October to November: autumn-sow pot marigolds, cornflowers and poppies once the soil has cooled, in October in colder areas and November in milder ones. The varieties that can take it are among our seeds for autumn sowing. Lift the dahlia tubers after the first frosty night and store them at about 5 degrees.
How we do it at Florea
We sow zinnias and China asters in two batches, one in April and one in mid-May. The late batch starts flowering in August and is at its best in September and October, when the early batch already looks tired. We let the dahlias stand until the first frosty night has blackened the leaves, then we lift the tubers within a week, cut the stems 10 cm above the tuber and put them in the dark at 5 degrees. We do not cut the flower heads of showy stonecrop at all in autumn. They stay standing until spring and give the border shape when everything else has collapsed.
Common mistakes
Cyclamen taken for hardy: the cyclamen in the shops is Cyclamen persicum and tolerates no frost. The hardy species Cyclamen hederifolium, the ivy-leaved cyclamen, is a different plant that flowers in early autumn in the border.
Dahlias and zinnias planted out in early May: a single frosty night takes them. Wait until late May or early June, once the risk of frost has passed.
Perennials planted in October: a Japanese anemone planted late has no time to root and rots in winter wet. Plant by September at the latest or wait until spring.
The saucer left under the pot: the water stands and the compost freezes into a lump. Take the saucer away in November.
Heather no longer watered in October: heather dries out more easily than it freezes. Water until the ground is frozen, and give it a splash on mild days in winter.
Author: Emma Vogiatzi
Fact-checked by Erik Hoekstra
Last updated 2026-10-20