What Seeds to Sow in September in Northern Europe (Cool Summer Climates)
September is firmly an autumn-sowing month in northern Europe and other cool-summer climates. Flower sowing now is mainly about hardy annuals and selected perennials for next year's garden, while more tender young plants are best started under cover. In the vegetable garden, concentrate on fast, cold-tolerant salads and leafy crops such as spinach, rocket, radish, lettuce and pak choi.
Shop Seeds for September Sowing in Northern Europe
Hardy Flowers to Sow in September for Next Year
September flower sowing in northern Europe is mainly about next year's display. Hardy annuals can be sown into prepared, free-draining soil while conditions are still suitable for germination. The earlier in September you sow, the more time young seedlings have to establish before winter.
Calendula
Calendula is one of the most dependable hardy annuals for autumn sowing. Choose Fiesta Gitana Mix, Ivory Princess, Funky Stuff or Bull's Eye.
Browse calendula seeds →Cornflowers
Cornflowers are excellent hardy annuals for autumn sowing. Young plants can establish before winter and often flower earlier the following year. Choose Blue Boy, Black Ball or Cornflower Mix.
Browse cornflower seeds →Nigella
Nigella is an easy hardy annual for cottage gardens, pollinators, cut flowers and decorative seed pods. Sow Miss Jekyll Skyblue, Miss Jekyll Rose or Nigella Sativa directly into a weed-free seedbed.
Browse nigella seeds →Annual Poppies
Hardy annual poppies are well suited to autumn sowing. Sow directly where they are to flower because their roots dislike disturbance. Recommended choices include Frosted Salmon Peony, Amazing Grey, Lauren's Grape, Dawn Chorus, Purple Peony and Black Peony.
Browse poppy seeds →Daucus Dara
Daucus carota Dara produces airy flower heads in burgundy, blush and cream. Autumn sowing can give plants a useful head start for flowering the following year.
Orlaya White Lace Flower
Orlaya Grandiflora White Lace Flower is a hardy annual for borders and cut-flower gardens. Sow into free-draining soil for an earlier display next season.
Linum Grandiflorum Mix
Linum Grandiflorum Mix can be autumn-sown in a sunny, sheltered and free-draining position. It is best suited to gardens where winter wet is not excessive.
Browse linum seeds →Cerinthe Pride of Gibraltar
Cerinthe Pride of Gibraltar can be autumn-sown in mild, sheltered gardens. In colder or exposed northern locations, starting under protection is more reliable.
Browse cerinthe seeds →Night-Scented Stock
Night-Scented Stock Starlight may be autumn-sown in sheltered, free-draining gardens. In very cold areas, save the seed for spring rather than relying on outdoor winter survival.
Browse stock seeds →Sow Early Where Winters Arrive Quickly
Autumn sowing becomes less reliable as latitude, exposure and winter severity increase. Sow during the first half of September where possible. In very cold, wet or exposed gardens, spring sowing may be safer for less winter-hardy annuals.
Flowers to Start Under Cover
A cold frame, unheated greenhouse or other bright, sheltered position greatly increases the range of flowers that can be started in September. Keep young plants cool rather than warm, and give them as much light as possible.
Sweet Peas
Autumn-sown sweet peas can develop strong root systems for earlier flowering next year. Sow in deep pots and overwinter in a cold frame or unheated greenhouse. Choose Cupid Pink or King Size Coronation Mix.
Browse sweet pea seeds →Snapdragons
Start snapdragons in trays or modules and overwinter the young plants in a bright, protected position. Choose Twinny Peach, Night and Day, Grandiflorum Mix or Snapshot Coral Bicolor.
Browse snapdragon seeds →Pansies & Violas
Start pansies and violas in trays and keep young plants cool, bright and protected. Choose Frizzle Sizzle Raspberry, Back to Black, Swiss Giants Mix, Inspire Plus Marina or Inspire Plus White.
Browse pansy seeds →Scabiosa
Scabiosa can be started under protection for stronger plants and earlier flowers next year. Choose Salmon Queen, Black Knight, Oxford Blue, Fire King, Fata Morgana, Summer Fruits, Paper Moon or Scabiosa Mix.
Browse scabiosa seeds →Bunny Tails
Bunny Tails (Lagurus ovatus) can be started in trays or pots in autumn. Overwinter young plants in a cold frame or unheated greenhouse rather than relying on exposed outdoor seedlings in very cold areas.
Cool, Bright and Protected
Autumn-sown flowers do not need a warm indoor room after germination. Cool temperatures and good light encourage sturdy growth. Protect young plants from severe frost, prolonged winter wet and slugs.
Perennials & Longer-Term Flowers to Start Now
These flowers are not intended to bloom this autumn. September sowing is about beginning germination or establishing young plants for a future season. Protect small seedlings during their first winter where necessary.
Delphiniums
Delphiniums can be started in trays during the cooler autumn period. Protect seedlings from slugs and severe winter weather. Choose Delphinium Mix or Delphinium Blue Cloud.
Browse delphinium seeds →Eryngium Blue Hobbit
Eryngium Blue Hobbit is a compact perennial sea holly. Autumn sowing allows seed to experience naturally cooler conditions before growth resumes.
Browse eryngium seeds →Icelandic Poppy
Icelandic poppies are naturally suited to cool conditions and can be started in autumn for flowering in a future season. Sow in trays and protect small seedlings during severe winter weather.
Browse poppy seeds →Oriental Poppy Brilliant
Oriental Poppy Brilliant is a perennial poppy with vivid scarlet-red flowers. Start in autumn for plants intended to develop and flower in a future season.
Browse poppy seeds →Hollyhocks — Early September
September is becoming late for hollyhock sowing in cool northern climates, but early sowings can still be tried in trays where young plants can be protected through winter. Choose Chater's Double Mix, Chater's Maroon, Chater's White or Hollyhock Nigra.
Browse hollyhock seeds →Lunaria — Early September
Lunaria is best started promptly in cool northern climates. Sow Lunaria Violet or Lunaria White in modules and protect young plants if severe winter weather is expected.
Browse lunaria seeds →Wildflower Mixes to Sow in September
Suitable wildflower mixtures can be autumn-sown into prepared, weed-free ground. Autumn sowing allows hardy species to establish before winter and can lead to earlier flowering the following year.
Organic Flowers: Meadow Mix
A meadow-style mixture for informal beds, larger garden areas and biodiversity-friendly planting.
Browse wildflower seed mixes →Organic Flowers: Wildflower Mixture
A colourful mixture of flowering species that can be autumn-sown for an earlier display the following year.
Browse wildflower seed mixes →Organic Flowers: Bee & Butterfly Mixture
A pollinator-friendly flower mixture for bees, butterflies and other beneficial insects. Autumn sowing is most successful in prepared, well-drained ground.
Browse wildflower seed mixes →Very Cold Areas
Autumn sowing is less predictable where winters are severe or the ground remains frozen or waterlogged for long periods. In these areas, spring sowing may be more reliable for some species.
Quick Vegetables to Sow in September
The September vegetable window is short in northern Europe. Concentrate on fast crops that tolerate cool weather and can be harvested as young leaves or small roots. Sow promptly and use a greenhouse, cold frame, cloche or fleece as autumn temperatures fall.
Organic Spinach Renegade
Spinach Renegade is one of the strongest September vegetable choices. Sow for autumn baby leaves or overwinter plants under protection for later harvests.
View spinach seeds →Organic Rocket Esmee
Rocket Esmee grows quickly in cool conditions. Sow small batches and harvest leaves young before growth slows significantly.
View rocket seeds →Organic Radish Cherry Belle
Radish Cherry Belle is one of the quickest root crops available for early-autumn sowing. Sow promptly and harvest while roots are small and crisp.
View radish seeds →Organic Lettuce Oakleaf Salad Bowl
Lettuce Salad Bowl is useful for repeated young-leaf harvests. Sow early in September or raise later sowings under protection.
View lettuce seeds →Organic Pak Choi Taisai
Pak Choi Taisai suits cooler conditions and can be harvested as baby leaves if the remaining season is too short for full-sized plants.
View pak choi seeds →Organic Welsh Onion Ishikura
Welsh Onion Ishikura Long White can be sown in early autumn and grown on for later use. Protection is useful where severe winter weather arrives early.
View Welsh onion seeds →What About Chard & Kale?
In mild or protected northern gardens, early-September sowings of Chard Fireworks, Kale Nero Di Toscana or Curly Kale Westland Winter may be useful for very young leaves. For established winter plants, however, these crops are more reliably started earlier.
Herbs to Sow in September
Herb sowing is limited by September in cool northern climates. Concentrate on coriander and parsley, and use containers or protected growing where temperatures fall quickly.
Coriander benefits from cooler conditions and is less likely to bolt rapidly. Sow small batches and protect later crops as winter approaches.
Parsley Italian Giant can be started early in September. Germination can be slow, so keep the compost moist and protect young plants through colder weather.
Easy to Grow & Small-Space Friendly
Containers are particularly useful in autumn because they can be moved into a sheltered position as temperatures fall. Choose quick salads, compact crops and hardy flowers rather than plants requiring a long, warm growing season.
Best Autumn Salad Pots
Spinach Renegade, Rocket Esmee, Lettuce Salad Bowl and Radish Cherry Belle.
Best Leafy Crops for Containers
Best Flowers for Pots
Calendula Fiesta Gitana Mix, Pansy Frizzle Sizzle Raspberry, Pansy Back to Black and Snapdragon Twinny Peach.
Best Herbs for Small Spaces
Organic Coriander and Organic Parsley Italian Giant are practical autumn herbs for pots close to the kitchen.
Easiest Beginner Vegetables
Radish Cherry Belle, Rocket Esmee, Spinach Renegade and Lettuce Salad Bowl.
Easiest Beginner Flowers
Calendula, cornflowers, nigella and hardy annual poppies.
Seeds Usually Too Late to Sow Outdoors in September
September conditions vary considerably across northern Europe, but many summer crops no longer have enough warmth, daylight or frost-free growing time to develop successfully from a new outdoor sowing.
Summer Flowers
Zinnias, cosmos, sunflowers, marigolds, nasturtiums, dahlias, gomphrena and other warm-season annuals should generally be saved for spring.
Tender Summer Vegetables
Courgettes, cucumbers, aubergines, pumpkins, squash, sweet corn and other warm-season vegetables are too late to start outdoors.
French Beans
Beans need warm soil and a longer frost-free period than a September northern European sowing can normally provide.
Peas
September is generally not the most useful sowing window for the pea varieties in this range. In many northern regions, wait for the appropriate spring sowing period instead.
Maincrop Root Vegetables
Carrots, beetroot, parsnips and similar root crops generally need more growing time than remains in the northern outdoor season.
Long-Season Brassicas
Broccoli, cauliflower, romanesco, Brussels sprouts and large winter cabbages should normally already be established rather than started from seed in September.
September Gardening Tips
September success depends on acting promptly, choosing cold-tolerant varieties and protecting young seedlings before winter conditions arrive.
The farther north you garden, the more important the first half of September becomes.
Most flowers sown now are intended to establish before winter and bloom next season.
Cold frames, unheated greenhouses, cloches and fleece extend the useful autumn sowing season.
Baby leaves and small roots are more realistic than large mature crops as daylight decreases.
Good drainage is particularly important for autumn-sown flowers and overwintering seedlings.
Shop Seeds for September Gardening
Hardy annual flowers, cool-season salads, protected autumn sowings and plants for next year's garden are the strongest choices for September in northern and cool-summer climates.