How to sow seeds indoors

A table displaying which months are best to sow, plant and harvest.
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
To do
To do

Do To do in January

Do To do in February

Do To do in March

Do To do in April

Do not To do in May

Do not To do in June

Do not To do in July

Do not To do in August

Do not To do in September

Do not To do in October

Do not To do in November

Do not To do in December

Growing from seed is a simple and economical way of raising new ornamental and edible plants for your garden. Sowing indoors allows you to raise plants from seed in early spring – much earlier than if sowing direct outside. This method also enables you to have plants ready to fill empty spaces as they arise. When growing salad crops, it’s a good idea to sow seed successionally every two weeks, to ensure you have a long season of fresh leaves to eat throughout summer.

You will need

  • Seeds
  • Seed compost
  • Seed trays or pots
  • Plant labels
  • Pencil or waterproof pen
  • Watering can with rose attachment
  • Polythene bag
  • Sheet of glass or a propagator

Total time:

Step 1

Fill small pots or seed trays with seed compost. Use a watering can fitted with a fine rose to moisten compost. Leave pots to drain.


Step 2

Sprinkle seeds evenly and thinly over the surface of the compost, leaving approx 2cm – 3cm between each one. Cover seeds with a thin layer of compost.


Step 3

Cover pot with a clear polythene bag or piece of glass, to preserve compost moisture. Place the pot on a well-lit windowsill or in a heated propagator. 


Step 4

Remove cover as soon as seedlings emerge and grow on in a warm place indoors. They will ready to be ‘pricked’ out when the second pair of leaves, known as ‘true’ leaves, emerge.


Step 5

When pricking out seedlings, handle them only by their leaves, not the stem. Fill a seed tray with seed compost and plant seedlings about 5cm apart, burying the root up to the base of the first leaves.


Step 6

After a couple of weeks, the young plants will be large enough to pot individually into 7.5cm pots, or planted outside in well-prepared soil. Handle plants gently, firm compost around them and water well. Don’t allow the soil or compost to dry out.


Don’t sow seeds too close together as they can be more prone to dying or ‘damping off’.