5 flowers to sow indoors in January for an early flush of blooms – get a head start on the growing season!
Sweet peas, snapdragons and more
It might be cold (freezing) outside, but garden preparations for 2026 start now – and there are actually several flowers you can sow indoors in January.
The list of things you can sow in January is longer than you’d expect, and if you’ve got a propagator (or even a heated propagator), the world’s your oyster.
‘It’s the perfect moment to get a head start on flowers, especially if you haven't sown in autumn,’ says Jane Westoby, creative director at The Hampshire Seed Company. ‘A warm propagator, bright light, and a little restraint with the watering can are the keys to success.’
1. Snapdragons
Snapdragons are one of my favourite flowers – I was blown away by the sea of blooms beside the statice at Bloom & Wild’s organic flower farm last year – and according to Jane, it’s one of the best for long-flowering displays. You can start sowing the seeds indoors this month (bonus points if you have a propagator).
‘Surface sow, and do not cover the seeds as they need light to germinate,’ Jane advises. ‘Keep them inside a propagator at 18–21°C, and as soon as the seedlings appear, remove them from the heat and give them plenty of light.’
Pinching out the growing tip once the plants have eight to 10 sets of leaves will encourage bushier growth, and Jane says you can even use the pinched piece of plant like a cutting to grow new snapdragons.
‘They root easily in water or vermiculite to double your plants,’ Jane adds. Westland Gro-Sure Vermiculite, £10.99 at Amazon, retains both soil moisture and nutrients.
Where to buy snapdragon seeds:
- Crocus: Antirrhinum majus 'Madame Butterfly Cherry Bronze' seeds produce flowers with a warm cherry-bronze hue.
- Thompson & Morgan: For soft pink and white shades, sow Antirrhinum majus 'Potomac Apple Blossom' F1 seeds.
2. Sweet peas
Another popular favourite! You can start growing sweet peas from seed indoors now, too. They’re one of the best flowers you can sow indoors in January, and you don’t even need a propagator to get them started.
‘Sow in deep pots or rootrainers, cover the seeds well and water thoroughly,’ says Jane. ‘Keep them at around 18°C and after germination, grow on somewhere cool and bright.’
A cold frame or unheated greenhouse is the ideal spot for sweet pea seedlings. Jane says that cool and slow-grown sweet peas actually produce stronger roots and plants when it comes to planting your sweet peas out, so don’t leave them inside the house once seedlings emerge.
I left mine to grow on my windowsill a few years ago, and they turned out to be some of the leggiest seedlings I’ve ever grown!
Where to buy sweet pea seeds:
- Thompson & Morgan: Sweet Pea 'Turquoise Lagoon' flowers mature to blue shades as they mature.
- Dobies: Sweet Pea 'Erewhon' is on my list. Look at those bicolour blooms!
3. Begonias
We often think of begonias as tuberous flowers, and while that’s true of many cultivars, fibrous-rooted Begonia semperflorens can be grown from seed as annuals – and they’re one of the best flowers to sow indoors in January.
‘Summer bedding plants that are slow to germinate and establish, like begonias, can be sown now to give them a head start,’ says Annelise Brilli, Thompson & Morgan’s horticultural writer.
Like snapdragon seeds, begonia seeds should be sown on the surface of the soil and handled gently. Maintaining a consistent temperature of anything from 21–25°C will give the seeds the best possible start, so it’s worth investing in a heated propagator. The Garland Super7 Electric Heated Windowsill Propagator is a number-one bestseller at Amazon, with seven mini propagators on one long tray.
‘Seedlings need the brightest position possible to prevent them from becoming leggy – ideally a sunny greenhouse,’ says Annelise. ‘Heat mats can also be useful to provide consistent warmth while seedlings are establishing.’
You can buy a heat mat for plants for £14.99 at Amazon, and even invest in some grow lights to compensate for January's shorter daylight hours, like these wolezek Grow Lights from Amazon.
Where to buy begonia seeds:
- Thompson & Morgan: Begonia semperflorens 'Options Mixed' produces a variety of colours.
- Dobies: Sow Begonia semperflorens 'Fairyland Mix' for semi-double rose-bud flowers.
4. Icelandic poppies
Towards the end of January, you can sow Icelandic poppies. The delicate, papery blooms open in spring, often lasting into early summer. Jane says these flowers don't need heat to germinate, and cool growing conditions after germination will actually encourage stronger stems.
'The seeds are very small and can easily get washed away, so water the compost before sowing, then surface sow without covering,' Jane advises.
Icelandic poppies actually rely on light more than warmth to germinate, so pop your seed tray on a bright windowsill once you've sown them. It's also wise to bottom water, Jane says, so that you don't wash the seeds out of place. A seed tray with holes, like this Garland seed tray from Amazon, is ideal.
'Icelandic poppies dislike heat and root disturbance, so pot on gently and don’t rush them,' Jane adds.
Where to buy Icelandic poppy seeds:
- Thompson & Morgan: Pollinators love Poppy 'Iceland Mixed'.
- Crocus: Sow flame-coloured Icelandic poppies.
5. Violas
Violas are one of the best bedding plants to add to your garden in April, but if you're keen to start them off from seed, they're also a flower you can sow indoors in January.
'Lightly cover the seeds,' says Jane. 'They prefer darkness to germinate. Keep them at around 15–18°, and once germinated, move the seedlings into bright, cooler conditions. Too much warmth leads to soft growth.'
Closely-related pansies can also be sown indoors towards the end of January.
Where to buy viola and pansy seeds:
- Thompson & Morgan: The stunning blooms of Viola hybrida 'Rose Shades' carry a sweet fragrance.
- Suttons: Pansy 'Chianti Shades' F1 produces ruffled, antique-looking flowers.
Indoor sowing kit for January
I've sown countless seeds in this unheated propagator. It's lasted me years, and the vents on the lid are brilliant for controlling air flow and humidity.
Or, invest in a heated propagator like this Amazon bestseller. It's the perfect size for a windowsill, with seven compartments.
These handy grow lights produce full spectrum white light, which mimics the sunlight at noon for optimal germination and growth.
So, there are plenty of flowers you can sow indoors in January for earlier blooms. Add them to your list of January garden jobs, and you'll be off to a flying start!
