What Seeds Can Be Sown in January Under Cover?

January may look quiet in the garden, but it is far from a dead month. While beds outside rest under cold, wet soil, indoors and under cover there is plenty a gardener can do. Sowing seeds in January is not about rushing the season — it is about giving slow-growing plants the gentle head start they need.

For UK gardeners especially, sowing under cover protects young seedlings from frost, heavy rain and low light, while still allowing growth to begin.

What does “under cover” mean?

Sowing under cover simply means protecting seeds from harsh winter conditions. This can include:

• a bright windowsill indoors

• a cold frame or greenhouse

• a heated propagator

• a porch or conservatory with good light

The goal is steady, slow growth rather than speed 🌿

Vegetables you can sow in January under cover

Not all vegetables are suitable for January sowing, but a few reliable crops do very well when started early.

Onions (from seed)

Onions need a long growing season and benefit greatly from an early start.

• sow thinly in trays or modules

• keep cool but frost-free

• transplant outdoors in spring

Leeks

Leeks are slow to mature and ideal for winter sowing.

• sow in small pots or trays

• grow on gradually

• hardy once established

Cabbage (early varieties)

Early cabbages can be started now under cover.

• choose spring or summer varieties

• avoid overcrowding seedlings

• harden off carefully before planting out

Spinach

Spinach prefers cool temperatures and is well suited to protected winter sowing.

• sow sparingly to avoid damping off

• keep compost just moist

• transplant or harvest young leaves

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Broad beans (in pots)

Broad beans started under cover often produce earlier crops.

• sow one seed per pot

• keep in a cool greenhouse or cold frame

• plant out once conditions improve

Flowers you can sow in January under cover

Some flowers benefit from a long growing season and reward early sowing with stronger plants and earlier blooms 🌸

Sweet peas

A classic January favourite.

• sow in deep pots or root trainers

• keep cool to prevent leggy growth

• pinch out tips once established

Antirrhinums (snapdragons)

These need time to develop before flowering.

• sow on the surface of compost

• provide plenty of light

• grow slowly until spring

Geraniums (pelargoniums)

Geraniums take time but flower beautifully from early summer.

• sow under warmth and light

• be patient with germination

• pot on carefully

Lobelia

A fine, delicate flower that benefits from early sowing.

• sow thinly and do not cover seeds

• mist gently

• transplant once large enough to handle

Herbs you can start under cover in January

Some herbs are slow growers and appreciate early indoor sowing.

• parsley

• chives

• coriander (in cooler conditions)

These will grow slowly now but strengthen as light levels improve.

Tips for successful January sowing

January sowing requires patience more than anything else.

• use clean pots and fresh compost

• avoid overwatering

• provide as much light as possible

• keep seedlings cool but frost-free

• label everything clearly

Remember: slow growth now is a good thing 🌱

A gentle beginning to the growing year

Sowing seeds in January under cover is less about quantity and more about intention. A few carefully chosen crops, nurtured slowly, can make the rest of the season calmer and more rewarding.

The garden may look asleep — but beneath the surface, the year has already begun.