Your winter seed sowing jobs

Flowers

Pelargoniums

Prepare for your own colourful summer displays over the next few months by sowing pelargonium seeds (often referred to as bedding geraniums) indoors between January and March. Sow into moist peat-free seed compost in pots or trays, cover thinly and place in a propagator between 21-24°C. Prick out seedlings into individual pots when large enough to handle. Harden off and plant out after the last frosts.

Rather than treating these half-hardy plants as annuals, you can bring them into a conservatory, frost-free greenhouse or place them on a sunny windowsill, before the first frosts, or take cuttings in August or September, which can then be overwintered indoors.

• How to grow geraniums
• Pelargonium types explained

Coleus

These tender perennials can be sown throughout the year, to grow as house plants or, if you want to grow them as summer bedding, start between January and March. Sow thinly onto a tray filled with damp peat-free seed compost and leave at 20-25°C to germinate either in a propagator or simply covered with a polythene bag. Prick out seedlings when the first true leaves appear and when plants are large enough to handle without damage.

There are many colourful coleus varieties available to grow from seed, ranging from the rich black and red crinkled foliage of ‘Black Dragon’ to the striking green and pink leaves of ‘Kong Rose’ and ‘Kong Lime Sprite’.

• How to grow coleus

Sweet peas

There is still time to get sweet peas sown undercover before the end of November, to get a head start on flowering next year. If you’ve missed the late autumn sowing window, don’t worry – you can sow seeds in the New Year from as early as the end of January. Sow sweet peas in deep pots, such as reusable root trainers or cardboard tubes, filled with peat-free compost and grow on in a frost-free place. Harden off seedlings and plant out in the garden after the last frosts.

Selecting next year’s sweet peas is always a challenge as there are so many tempting choices. We love old-fashioned varieties from the Grandiflora group such as ‘Matucana’ and ‘Painted Lady’ with their bi-coloured blooms and intense scent. Alongside these gorgeous sweet peas, we also grow Spencer varieties, including the wine-red flowers of ‘Beaujolais’, and ‘Mollie Rilstone’ with her delicate white petals with the softest pink picotee edges.

Perennial sweet peas (Lathyrus latifolius), also known as broad-leaved everlasting peas, look wonderful scrambling up fences and through shrubs. These low-maintenance plants are a sustainable choice as they don’t need to be raised from seed every year. Everlasting peas have delightful flowers, but they are unscented. Their specific epithet ‘latifolius’ refers to the plant’s broad leaves, whereas the name of the annual sweet pea, Lathyrus odoratus, emphasises the beautiful fragrance of the flowers. Everlasting peas are good for attracting bees to the garden, especially long-tongued bumblebees. It’s worth noting that sweet peas are toxic.

• Video - Sowing sweet pea seeds
• Best sweet peas for scent
• Best sweet peas for cut flowers

Vegetables

Onions

Onions are often grown from sets which can be planted in autumn or spring. Growing from seed is more cost-effective, though it takes longer. Sow onion seeds under cover in peat-free seed compost in modules from early January onwards. Seedlings can be hardened off and transplanted outside once the soil warms up in March or April.

Good choices to grow from seed include ‘Bedfordshire Champion’ which has large, globe-shaped bulbs that store well, ‘Red Baron’ with its attractive, deep crimson skin and ‘Early Paris White’, a particularly hardy variety that produces small white onions ideal for pickling.

Seeds can also be sown outside once the weather warms and the soil is workable in late winter to mid-spring. Sow thinly at a depth of 2cm, leaving 30cm between rows. Thin seedlings to 15cm apart for medium-sized onions and 18cm apart to grow larger bulbs. Onions need a fertile, moisture-retentive soil in a sunny spot.

• How to grow onions from seed

Garlic

If you get garlic cloves in the ground any time from the beginning of November through to early winter, they will have the period of cold weather necessary to develop into good-sized bulbs next year. Alternatively, varieties suitable for planting in winter and spring such as ‘Solent Wight’ and ‘Picardy White’ can be sown right through to March. Always buy certified garlic bulbs of named varieties from reputable suppliers as these will be suitable for UK growing conditions and will come from virus- and disease-free stock. Don’t use bulbs from the supermarket.

Soft neck varieties like ‘Cristo’ have many small cloves and generally store well. We like ‘Early Purple Wight’ – an attractive soft neck with purple-tinged bulbs that taste delicious. It matures quickly – bulbs are ready to harvest from mid-May, but this variety is best used soon after harvest and, if stored, should be used within three months.

Hard neck varieties are more strongly flavoured and produce fewer cloves in each bulb. They are usually hardier than soft neck garlic, so are more suitable for colder areas. ‘Extra Early Wight’ and ‘Caulk Wight’ are ideal for autumn and early winter planting. Place individual cloves with the tip 2.5cm beneath the surface, pointed end up, spacing them 15cm apart in well-drained soil in a sunny spot. Garlic bulbs should be ready to harvest from May to July. Onions and garlic are toxic for pets and garlic is a skin irritant.

• How to grow garlic

BBC Gardeners' World Magazine subscribers save 10% all year round on garden shopping*

As part of your subscription, you can enjoy a 10 per cent saving on your shopping from more than 25 carefully chosen online partners. 

Browse the full list of suppliers where you can save money, and get your discount codes.

*Excludes delivery and some products, not valid with any other offer.

Peas

Peas suitable for autumn sowing until early November in mild areas include fast-growing ‘Douce Provence’ and hardy dwarf variety ‘Meteor’ which reaches around 45cm in height. Sow seeds in a shallow trench 4-5cm deep, spacing them 10cm apart and leaving a space between rows equal to the eventual height of the plants. Protect autumn-sown peas with cloches over winter or grow in covered containers.

Sowing first early peas under cover in late winter or early spring in guttering or pots also gives you a head start and helps avoid damage from mice, slugs and cold weather. Plants can then be hardened off and planted out in mid-spring by sliding the whole section in the guttering into a shallow trench, or simply transplanting individual plants.

• How to grow peas