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Hello, fellow flower lovers! Isn't it just beautiful to see the seasons change, bringing along a new wave of life and vibrancy?
As September arrives and we start to feel the crisp breeze of autumn, it's the perfect time to start thinking about next year and sow seeds in your gardens.
The best seeds to sow in September are hardy annuals, but you can also add to this with spring bulbs and planting perennials and shrubs while the ground is still warm.
Let’s take a deeper look at what seeds to sow in September and what we can do now to get our flower garden ready for next year.
The September seed sowing deadline
September is a magical month for gardeners. It's a time where we get the best of both worlds, we have all of the late summer flowers still in bloom, and we have the joy of thinking ahead and deciding how we want to shape our garden for the coming year. Many of you may have started your hardy annuals in August. I chatted about this in a post about the seeds to sow in August. But don't worry if you missed it, the list of seeds you can sow hasn't changed a bit.

Now, if you're anything like me, planting seeds in August can sometimes slip to the bottom of the to-do list. After all, we're still relishing in our late summer flower harvest, the peak time for dahlia, so it’s worth enjoying their spectacle. But, before we know it, poof! Time's up to grow those seedlings for planting.
So if you are just starting to sow seeds in September it is not a problem at all! It just means you've made a solid choice to keep your seeds cozy over winter in the greenhouse. This is simply because there's just not enough time to grow them big enough to plant before the autumn equinox around September 22nd (ish).
Don’t be put off, there is an upside of sowing in autumn – your seedlings will be raring to go come next spring! You can even get them planted into the ground before the last frost date, which is a bit earlier than if you sow them in spring. This means you'll have more room for those tender annuals when the time comes, which is always a bonus.

What else can you plant in September
If you're all caught up with your seed sowing, why not turn your attention to spring bulbs?
Just to name a few – Narcissus, crocus, fritillaria, muscari – are all bulbs that you can happily plant from mid-September. They'll kickstart your flower season with a splash of colour next March or April – long before your seeds have even thought about blooming.
Make sure you hold off until October/November for the tulips, they like to be planted when it is colder.
Best seeds to sow in September
If you want to buy the best seed for hardy annual cut flowers, I sell them in my seed shop.
Here are a few hardy annuals that you can try out this September:
- Agrostemma (corncockle)
- Ammi majus
- Antirrhinum (snapdragon)
- Bells of Ireland
- Cornflowers
- Cerinthe major
- Daucus
- Dill
- Grasses
- Larkspur
- Marigolds
- Nigella
- Poppies
- Scabiosa
- Sweet peas
As we sow our seeds this September, we're partaking in a ritual as old as time. We're connecting with nature, nurturing the earth, and creating a space of beauty and serenity.
As the famous naturalist photographer said:
“Autumn is a time for harvesting, of gathering, it is a time of sowing, of scattering abroad” Edwin Way Teale
So, what are you waiting for? Don your gardening gloves, grab your seeds, and join us in making this September a fantastic spring!