What to plant in January

You will need:

It’s exciting to be able to start sowing a variety of different seeds at this time of year, and to give them the best chance you might find that it's worth investing in additional kit, which we've suggested below.

• Heated propagator: available in a range of shapes and sizes, we’ve suggested the best heated propagators, which provide the perfect growing conditions for seedlings.
• Grow light: grow lights are invaluable for increasing light levels early in the year, when conditions are often cloudy and day length is short.
• Cold frame: if you’re prepared to add a bit of extra insulation, a cold frame offers protection against wintry weather and can help hardy seeds get off to a flying start too – check out our pick of the best garden cold frames.
• Greenhouse: for those of you who have been toying with the idea of a greenhouse, we’ve got handy guides packed with information about how to choose the best greenhouse, as well as 12 of the most useful greenhouse accessories. No outside space? No problem – our round-up of the best indoor greenhouses is just for you.
• Tools, pots and supports: once your seedlings are ready to plant out later in the year, you'll find that a hand trowel is a great tool for the job. Our expert testers have put a range of styles through their paces to find the best garden hand trowels, so you can buy in confidence. If you're looking to create eye-catching containers with your homegrown plants, we've also selected the best eco friendly plant pots, while our pick of decorative garden obelisks and plant supports will help keep your sweet peas looking in tip top condition.

Vegetables to grow in January

Chillies

When to harvest: July to October.

How to grow: sow 2-3 seeds thinly per small individual pot using peat-free seed compost. Cover seeds to their own depth with vermiculite and keep in a heated propagator (if you can control its heat setting, set it to 21°C). Once seedlings have germinated, remove the lid of the propagator and – if you can – turn the heat down to 16-18ºC. Consider using a grow light to stop the seedlings from becoming leggy.

When seedlings are 2–3cm tall, take them off the propagator and pot them on into individual pots of peat-free, multi-purpose compost, moving them somewhere warm – chillies do best with a night-time temperature no lower than 15ºC, so room temperature is fine. Bear in mind that windowsill temperatures may drop below 15ºC at night.

If light levels are still low, continue using the grow light until day length increases. Pot on into a slightly larger pot when roots begin to show through the drainage holes. They will be ready to grow in a greenhouse or conservatory when night-time temperatures have reached 15ºC.

• How to grow chillies
• Buy chilli seeds from Thompson & Morgan and Crocus

Aubergines

When to harvest: July to October.

How to grow: like chillies, aubergines should be sown thinly per small individual pot of peat-free seed compost, and covered to their own depth with vermiculite. Keep in a heated propagator set it to 21°C, then remove the cover and turn down the heat to 16-18ºC once seeds have germinated. Consider using a grow light to stop the seedlings from becoming leggy.

When seedlings are 2–3cm tall, pot them on into individual pots of peat-free, multi-purpose compost, keeping them somewhere warm like a sunny windowsill, but you may need to move them away from the window at night if temperatures dip below 15ºC. Continue using the grow light if necessary.

Pot on into a slightly larger pot when roots begin to show through the drainage holes. They will be ready to grow in a greenhouse or conservatory when night-time temperatures have reached 15ºC.

• How to grow aubergines
• Buy aubergine seeds from Thompson & Morgan and Crocus

Basil

When to harvest: July to October.

How to grow: sow basil thinly on the surface of pots or trays of seed compost, cover with vermiculite. Keep temperatures at around 20°C, ideally in a heated propagator. Consider using a grow light to stop the seedlings from becoming leggy.

When seedlings are big enough to handle, pot them on into individual pots filled with a peat-free, soil-based compost mixed with multi-purpose compost. Pinch out tips to encourage bushy plants. Keep warm indoors or plant outside from June to August.

• How to grow basil
• Buy basil seeds from Thompson & Morgan and Crocus

Onions

When to harvest: July to October.

How to grow: sow seed into modular cells of moist, peat-free seed compost, ideally one seed per module but two to three seeds is fine – you'll just get smaller onions. Keep warm at 10-16ºC, in a heated propagator or warm windowsill. Once seeds have germinated, keep in a bright spot at room temperature, and keep compost moist. Pot the plants on if you need to, taking care not to split up the clumps of two to three growing together. Then harden them off in spring before planting into well-prepared ground, spacing them 5–10cm apart, in rows 25–30cm apart.

• How to grow onions from seed
• Buy onion seeds from Thompson & Morgan and Suttons

Broad beans

When to harvest: May to August.

How to grow: (if you live in a mild area only, otherwise hold off until March) sow seed individually into modular cells or small pots of moist, peat-free seed compost. There's no need to provide heat as they will germinate within three weeks in an unheated greenhouse or cold frame – protect from mice if necessary. Keep well watered. After a further three weeks, pinch out the tips of each plant to encourage bushy growth, and harden off to acclimatise them to outside conditions. Then plant out into well-prepared ground, spacing them in single rows 45cm apart or double rows 20cm apart, with 60cm between rows. If frost is forecast, cover with a cloche or horticultural fleece.

• How to grow broad beans
• Buy broad bean seeds from Thompson & Morgan and Suttons

Flowers to grow in January

Geraniums

Flowers June to October/November.

Sow geraniums thinly in small seed trays using seed compost plus 10 per cent grit – barely bury the seeds.

Keep temperatures at 24°C (75°F), ideally in a heated propagator. Germination takes 3-12 days.

• Buy geranium seeds from Thompson & Morgan and Suttons

Sweet peas

Flowers May/June to August.

Sow sweet peas 6cm deep in 'tubes' or 7cm pots using seed compost plus 10 per cent grit.

Minimum temperature 12°C (55°F), keep in an unheated greenhouse or cold frame – germination 10-14 days.

• Buy sweet pea seeds from Thompson & Morgan and Crocus

Dahlias

Flowers July to October/November.

Sow 1-2 dahlia seeds in cells or small pots using seed compost plus 10 per cent vermiculite.

Minimum temperature 18-21°C (65-70°F), germination takes approximately 5-20 days.

• Buy dahlia seeds from Thompson & Morgan and Suttons

Delphinium

Flowers June and July.

Sow delphiniums thinly in trays of seed compost plus 10 per cent vermiculite, barely cover with vermiculite.

Keep in fridge for three weeks, then keep temperatures at 15-21°C (59-70°F) – germination takes 7-28 days.

• Buy delphinium seeds from Thompson & Morgan and Crocus

Begonias, tuberous and bedding types

Flowers July to October/November.

Sow begonias thinly on the surface in trays of seed compost with a thin layer of vermiculite.

Keep temperatures at 19-24°C (66-77°F). Germination is slow, 15-60 days of light is essential.

• Buy begonia seeds from Thompson & Morgan and Suttons

Petunias

Flowers late June to September.

Sow petunias thinly on the surface in small trays of seed compost plus 10 per cent vermiculite and lightly dust with vermiculite to barely cover.

Keep temperatures at 24-27°C (75-80°F). Germination takes 14 days, but plenty of light is essential.

• Buy petunia seeds from Thompson & Morgan and Suttons

Iceland poppies

Flowers June to October.

Sow 2-3 Icelandic poppy seeds on the surface of each small individual pot of seed compost plus 20 per cent fine grit.

Minimum temperature is 12°C (55°F), keep in a cold frame. Germination takes 14-21 days.

• Buy Icelandic poppy seeds from Thompson & Morgan and Suttons

Coleus

Foliage display June onwards.

Sow coleus thinly in pots or a tray using seed compost + 10 per cent vermiculite, covering to its own depth.

Keep temperatures at 19-24°C (65-75°F), in a heated propagator. Germination takes 10-20 days, depending on temperature.

• Buy coleus seeds from Thompson & Morgan and Suttons