What to sow in January

January is a quiet month outdoors, but a surprisingly productive one under cover.

• Begonia, lobelia, pelargonium and salvia seeds can be sown now in a heated greenhouse or propagator. These tender annuals need a long head start to flower well in summer.
• Sweet peas sown in autumn can be potted on this month. If you didn’t sow any earlier, you can sow a fresh batch now — they’ll still make strong, early plants.
• Keep all seedlings in good light and turn trays regularly so they grow straight rather than leaning towards the window.

What to do in January

• Clean the greenhouse, cold frames and pots so everything is ready for spring sowing. A good scrub helps prevent pests and diseases lingering from last year.
• Prune apple and pear trees while they’re dormant. Remove crossing branches and open up the centre to improve airflow.
• Start forcing rhubarb by covering a crown with a large pot or forcing jar. This encourages tender, early stems.
• Put out food and water for birds — they’re invaluable allies in pest control later in the year.
• Plan your vegetable crop rotation. Rotating crops helps prevent disease build‑up and keeps the soil healthy. A little planning now saves a lot of trouble later.