September is a busy month in the garden. Summer may be coming to an end, but there is still plenty to sow, plant and harvest before the colder months arrive.
It is also the perfect time to start preparing your garden for autumn and winter. From planting spring-flowering bulbs and sowing winter salads to collecting seeds, looking after your lawn and bringing tender plants under cover, there are plenty of September gardening jobs to get stuck into.
Whether you’re gardening at home, growing in containers or tending to an allotment, here’s everything you need to know about what to grow and do in the garden in September
What can you grow in September?
September is a great month for growing cool season crops, planting for spring and making the most of the final weeks of the summer growing season.
You can still sow vegetables and salads, plant hardy perennials and trees and start getting spring bulbs into the ground ready for a colourful display next year.
What to sow in September
There are still plenty of seeds that can be sown in September. As temperatures begin to cool. Focus on crops that can cope with shorter days and cooler conditions.
Vegetables to Sow in September
Spinach
September is a good time to sow spinach for autumn and winter harvests. Choose a sunny or partially shaded position and keep the soil moist while seeds establish.
Winter salads
Sow winter salad leaves in September for fresh leaves through the cooler months. Hardy varieties can be grown outdoors, while more tender crops will benefit from a greenhouse, cold frame or sheltered position.
Rocket
Rocket is quick to grow and can still be sown during September for a final crop before winter. Sow little and often for a continued supply of leaves.
Radish
Fast growing radishes can be sown in early September for a final crop before winter. Choose a sunny position and sow small batches for succession.
Spring onions
Hardy varieties of spring onions can be sown in September and will establish during autumn and overwinter for an early crop.
Mustard greens
Mustard greens are another quick growing crop that can provide fresh leaves during autumn. Sow in container beds or undercover depending on the variety.
September sowing tip: As the weather becomes cooler, check seed packets for recommended autumn sowing times and choose hardy varieties where possible
Flowers to sow in September
September can also be a useful month for sowing certain flowers.
Sweet peas
Hardy sweet peas can be sown in early autumn. Starting them now gives plants plenty of time to establish strong roots before winter.
Never grown sweet peas before? Check out our sweet pea growing guide!
Hardy annuals
Some hardy annuals can be sown in September so they can establish before winter and flower earlier the following year.
Wildflower seeds
September can be a good time to sow wildflower mixes, particularly where the soil is warm and there is moisture available.
What to plant in September
September is an excellent month for planting. The soil is often still warm for summer, while cooler air temperatures and increased rainfall can help new plants establish.
Plant spring bulbs
If you want your garden filled with colour next spring, September is the time to start planting spring-flowering bulbs.
Daffodils, crocuses, hyacinths, alliums and many other spring bulbs can be planted in autumn. Tulips are usually best planted a little later in autumn.
Plant bulbs in borders, containers, lawns or naturalised areas for a welcome display after winter.
Looking for more advice? See our complete guide to planting spring bulbs.
Plant trees and shrubs
September is a good time to start planting trees and shrubs. The warmer soil gives roots time to establish before winter.
Make sure newly planted trees and shrubs are watered thoroughly, particularly if conditions remain dry.
Plant perennials
Hardy perennials can be planted in September while the soil is still warm. Planting now gives them time to settle in before winter and get established ahead of next spring.
It’s also a good opportunity to refresh borders, fill gaps and add new colour to your garden.
Plant fruit trees and soft fruit
As summer comes to an end, it’s a good time to start planning your fruit garde
Apple, pear, plum and cherry trees, along with fruit crops such as raspberries or gooseberries, can be planted during autumn.
See our guide to planting fruit trees for more advice.
What to harvest in September
There is still plenty to harvest in September as the summer growing season comes to an end.
Depending on what you have grown, look out for:
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Apples
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Pears
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Plums
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Runner beans
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French beans
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Courgettes
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Tomatoes
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Sweetcorn
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Carrots
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Beetroot
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Potatoes
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Autumn raspberries
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Blackberries
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Chillies
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Cucumbers
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Pumpkins and squash
Keep harvesting regularly to encourage plants to continue producing. September is also a good time to bring in crops that could be damaged by increasingly cool or wet weather.
September gardening jobs: what to do in the garden
September is all about preparing for the season ahead. Rather than waiting for autumn to arrive, use this month to get ahead with planting, sowing and garden maintenance.
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Collect and save seeds
September is an excellent time to collect seeds from flowers and vegetables that have finished flowering or producing.
Choose healthy plants and allow seed heads to dry before collecting. Store seeds somewhere cool and dry in clearly labelled containers so you know what you’ve saved for the next year.
See our complete guide on collecting seeds for more information.
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Plant spring bulbs
Get ahead for spring by planting early spring flowering bulbs.
Daffodils, crocuses and other bulbs can be planted during September, with more varieties becoming available as autumn progresses.
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Repair and prepare your lawn
September is one of the best times of year to give your lawn some attention.
Repair bare patches, overseed thin areas and consider scarifying where moss and thatch have built up. The soil is still warm, giving new grass seed a good opportunity to establish before winter.
Keep mowing as needed, but avoid curing the grass too short.
See our autumn lawn care guide for more tips on how to care for your lawn in autumn
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Divide overcrowded perennials
September can be a good time to divide established herbaceous perennials that have become overcrowded.
Carefully lift plants and divide them into smaller sections, making sure each division has healthy roots and shoots. Replant them promptly and water thoroughly.
Dividing perennials can help rejuvenate older plants while giving you new plants to fill other areas of the garden.
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Clear spent summer crops
As summer crops begin to finish, begin clearing away plants that have stopped producing.
Remove finished tomatoes, courgettes, beans and other spent crops to make space for autumn planting. Add healthy plant material to your compost heap where appropriate.
Clearing beds now also makes is easier to prepare the soil for new crops
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Sow winter crops
Make use of empty space by sowing crops that can grow through autumn and winter.
Winter salads, spinach, spring onions and other hardy crops can help keep your vegetables garden productive as the seasons change.
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Plant trees, shrubs and perennials
Take advantage of warm soil and cooler temperatures to establish new plants.
September is a great time to add trees, shrubs and hardy perennials to your garden, giving roots time to establish before winter.
Remember to water new planting thoroughly while the weather remains dry.
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Start preparing tender plants
You don't need to fully winter proof the garden yet, but September is a good time to start preparing.
Check greenhouses and sheltered spaces, clean pots and containers and work out which tender plants will need protection as temperatures drop.
Having everything ready means you’re less likely to be caught out by an early cold snap.
September allotment jobs
September is a productive month on the allotment, with plenty of harvesting and preparation to do.
Clear spent crops
Remove crops that have finished producing and clear away any diseased or damaged plant material.
Sow winter crops
Make use of available space by sowing winter salads, spinach, spring onions and other suitable overwintering crops
Plant spring bulbs
Plant suitable spring flowering bulbs around the allotment for an early burst of colour next year.
Plant perennials, trees and shrubs
September is a good time to start planting hardy plants while the soil remains warm.
Collect seeds
Save seeds from healthy plants that have performed well during the growing season. Dry them thoroughly before storing in labeled containers.
Keep harvesting
Continue harvesting crops regularly. Courgettes, beans, tomatoes, potatoes, apples and many other crops can all be ready during September.
Prepare empty beds
Once a crop has finished, clear the bed and improve the soil with compost por well rotted organic matter ready for future planting.
Clear weeds
Stay on top of weeds while the soil is still workable. Removing perennial weeds now can save time when the garden becomes active again in spring.
Clean and organise tools
Give your tools a clean and check that everything is in good working order before the busier autumn gardening season gets underway.
September gardening checklist
Save this checklist and tick off your September gardening jobs as you go.
Sow
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Spinach
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Winter salads
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Rocket
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Radish
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Spring onions
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Mustard greens
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Sweet peas
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Wildflower seeds
Plant
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Spring bulbs
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Tree and shrubs
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Perennials
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Fruit trees
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Soft fruit
Garden jobs
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Collect and save seeds
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Plant spring bulbs
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Repair and prepare the lawn
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Divide herbaceous perennials
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Clear spent summer crops
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Sow winter crops
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Plant trees, shrubs and perennials
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Start preparing tender plants
September gardening FAQs
What vegetables can I sow in September?
Vegetables and salads that can be sown in September include spinach, winter salads, rocket, radish, spring onions and mustard greens. Choose varieties that are suitable for autumn sowing.
What flowers can I plant in September?
September is a good month to plant hardy perennials and start planting spring-flowering bulbs. Some hardy annuals, sweet peas and wildflower seeds can also be sown during autumn.
Is September too early to plant spring bulbs?
No. September is a good time to start planting many spring flowering bulbs, particularly early flowering varieties such as daffodils and crocuses. Tulips are generally planted in later autumn.
What bulbs should I plant in September?
Daffodils, crocuses, hyacinths and alliums can be planted from early autumn. Always check the instructions on individual varieties for their recommended planting time and depth.
What should I do to my lawn in September?
September is an excellent month for lawn repair and preparation, removing moss and thatch where necessary, repairing bare patches and overseeding thin areas while the soil is still warm.
What should I do with seeds in September?
Collect seeds from healthy plants once they have fully matured and dried. Store them somewhere cool and dry in labeled containers ready for sowing next year.
September is all about making the most of the end of summer while getting ahead for autumn and winter.
From collecting seeds and harvesting the last of your summer crops to planting spring bulbs, repairing your lawn and sowing winter salads, there is plenty to do in the garden this month.