How to Save Dahlia Seeds: A Step-by-Step Guide for UK Gardeners
- untamedallotment
- Oct 3
- 2 min read
Discover how to collect, dry, and store dahlia seeds for a sustainable, surprise-filled garden.
Why Save Dahlia Seeds?
Most gardeners grow dahlias from tubers, but saving seeds is a magical way to grow something new. Unlike tubers, dahlia seeds won’t produce exact copies of the parent plant. Instead, each seed is a surprise — a brand-new flower, colour, or form unique to your garden.
Saving your own seeds is sustainable, thrifty, and a lovely way to keep your garden evolving year after year.
How to Identify Dahlia Seed Heads
Seed heads look different from flower buds:
Buds are round and usually face downwards.
Seed heads are pointed and tend to face upwards.
As the flower fades, the centre swells and firms instead of staying soft and petal-filled. That’s your seed head beginning to form.
Helping Seeds Mature (Especially in UK Autumns)
In damp climates, dahlia seed heads need a bit of help to ripen. Here’s what we do in our Surrey garden:
Remove any wet or rotting petals clinging to the bloom as it begins forming seeds.
Gently squeeze out excess moisture from seed heads after rain to reduce rot.
Cut heads and bring them indoors to finish maturing, since seeds in the middle are pollinated later and need an extra few days (or a week).
This protects against rot in wet UK autumns and allows the plant to direct its energy into ripening more seeds.
When Are Dahlia Seeds Ready?
A ripe seed head should feel solid when squeezed. To check, peel back the outer layers:
Seeds should be dark black, hard, and teardrop-shaped.
Pale or soft seeds need more time to mature.
You can even place the whole head in water for a short time to allow seeds to continue ripening.
Harvesting and Drying Dahlia Seeds
Once seed heads are brown and papery-dry, crumble them open.
Pick out the seeds.
Discard any that bend instead of holding their shape under pressure.
If seeds feel damp, spread them on kitchen roll and allow them to dry completely before storing.
Storing Dahlia Seeds for Next Year
Place your fully dried seeds in a paper envelope or bag, clearly labelled with the variety and year. Store in a cool, dry place such as:
A drawer or cupboard (away from bathrooms and kitchens).
A seed storage tin.
A paper envelope kept inside a cardboard box.
Avoid windowsills, greenhouses, or anywhere damp.
The Joy of Dahlia Seeds
By saving dahlia seeds, you’re not just preserving plants — you’re creating something new. Each seedling is a little experiment that could reveal an entirely new dahlia bloom. It’s the perfect blend of sustainability, curiosity, and garden magic.
✨ Will you be saving your dahlia seeds this year, or do you prefer sticking with tubers? Share your thoughts below — we’d love to hear!
