January may feel like the quietest month in the garden, but for those in the know, it’s when the growing year truly begins. While frost still grips the ground outside, the simple act of starting your seeds indoors allows you to get ahead. Whether you’re completely new to gardening or simply looking to make better use of winter downtime, we wanted to create the ultimate seed starting guide to help walk you through what to sow indoors this January, and how to do it successfully, even if you’ve never planted a seed before.
Why Start Seeds Indoors in January?
In the UK climate, January is far too cold for most outdoor sowing. However, many plants benefit from a long growing season, and starting them indoors gives them exactly that.
By sowing seeds now, you:
- Extend the growing season
- Grow stronger, healthier plants
- Enjoy earlier harvests and blooms
What Seeds to Sow Indoors in January
Not all seeds are suitable for January sowing, but several popular vegetables, herbs, and flowers thrive when given an early indoor start.
Vegetables to Start Indoors
These are some ideal choices for beginners:
- Chillies and sweet peppers
Slow-growing and heat-loving, these benefit hugely from an early start.
- Aubergines
Another warmth lover that needs time to mature in the UK climate.
- Tomatoes
Particularly larger varieties, which appreciate extra growing time.
- Onions (from seed)
An excellent option if you’re aiming for a good summer harvest.
Herbs Worth Starting Now
- Basil
A windowsill favourite that germinates quickly indoors.
- Parsley
Slow to germinate but reliable once established.
- Chives
Easy to grow and perfect for containers.
Flowers for Early Colour
- Sweet peas
January-sown sweet peas often produce stronger plants and earlier flowers.
- Geraniums
Ideal for patios and balconies later in the year.
- Begonias
Particularly suitable for indoor or sheltered growing.
What You’ll Need to Get Started
You don’t need a greenhouse or any specialist tools. Keep it simple:
- Seed compost (light and free-draining)
- Small pots, trays, or recycled containers
- Labels (you will forget what you’ve planted)
- A warm windowsill or propagato
Sow seeds according to the packet instructions, water gently, and cover lightly if required. Most importantly, keep them warm and consistently moist but not wet.
Light, Warmth and Care
To sow indoors this January you will be best placing seedlings on the brightest windowsill available, ideally south-facing, as light levels can be quite low. The shortest day has already past so the days will be getting brighter at least but low sun and overcast weather can make it a bit tricky. Rotate pots every few days to prevent seedlings leaning towards the light.
Avoid overwatering – this is one of the most common beginner mistakes! Compost should feel damp, not soggy.
As seedlings grow in their pots you will want to thin them out into more pots so each plant has the space to develop properly.
A Thoughtful Start to the Gardening Year
When January can feel tough or slow or like there’s nothing much to look forward to, setting your seeds indoors is a really nice, intentional job to give yourself. With just a few seeds and a warm windowsill, you can start a new hobby and routine whilst setting yourself up the rest of the growing and flowering year. If this is your first time trying early growing from seeds, don’t beat yourself up if things don’t go exactly to plan. Some may thrive whilst others don’t take at all or progress may be slow and you might find impatience setting in. Everyone has to start somewhere and taking an interest in growing your own is a positive step, perfect or not. You are allowing yourself time to observe, learn, and refine, the hallmarks of good design, whether in the garden or the home.
Start Your Seeds
Seed starting indoors doesn’t require experience or perfection. It simply requires curiosity and a willingness to begin. By following The Ultimate Seed Starting Guide: What to Sow Indoors This January, you’ll be laying the foundations for a garden that feels both personal and rewarding.
And when the days begin to lengthen, you’ll already be ahead.
If you’re ready to start your new garden journey, click here to book your consultation.