Thompson & Morgan

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What to sow and grow in the garden this month

What to sow and grow in March


Find out what to plant in March with our seasonal list of flowers, fruit, vegetables and seeds. These can be ordered now for sowing, growing and harvesting over the coming months!


Flowers to sow and grow


    in the 

greenhouse greenhouse  In the greenhouse / indoors


  • • Sow Aster in a heated propagater for summer and autumn colour.
  • Ageratum sown indoors now will bring a splash of blue to your summer beds.
  • • Sow Brachyscombe in a heated propagater now for filling out your baskets and containers.
  • Coreopsis can be sown indoors or in a heated greenhouse.
  • • For a fiery theme to your beds this year try sowing Celosia in a heated propagator.
  • Cleome needs fluctuating temperatures to germinate well. Ensure that the temperature drops at night by sowing on a windowsill indoors as early as possible in the season.
  • Dahlia seeds indoors sown now will produce tubers for lifting in the autumn.
  • • Sow summer bedding plants in a heated propagater such as Lobelia, Busy Lizzies, Petunias and Geraniums.
  • • Try growing versatile Salvia under glass for a long-lasting display throughout the summer and autumn.
  • • Sow Stocks on a bright windowsill now for a delicious fragrance in your summer garden.
  • • Plant your Begonia tubers in the greenhouse this month, positioning them just below the compost surface with the indented side facing upwards. If you didn't have time to order Begonia tubers, try growing Begonia plug plants.


  • direct sow outdoors seed packet  Direct sow outdoors


  • Wildflower seed mixtures are great for bees and butterflies, and for adding colour too. Direct sow into well prepared soil now.
  • • Sow Sweet Peas outdoors where they are to flower.
  • • If the soil is workable then direct sow hardy annuals such as Californian Poppies, Clarkia and Cornflowers into well prepared soil.


  • Fruit & Vegetables to sow and grow


      in the 

greenhouse greenhouse  In the greenhouse / indoors


    • Aubergines need a long growing season so start the seeds off in the propagater now.
    • • Start basil seeds off now on your kitchen windowsill or for planting out after the risk of frost.
    • • Sow Brussels sprouts now under cover.
    • Cauliflowers can be started off now under cover.
    • Celeriac needs a long growing season so start them now under cover.
    • • Sow celery indoors from the middle of the month onwards.
    • • Sow chilli peppers and sweet peppers indoors now.
    • • Sow perennial herbs such as lemon balm, rosemary, sage, oregano and thyme under cover.
    • • For greenhouse growing, sow cucumbers and gherkins in warmth now.
    • • Sow tomato seeds under glass for greenhouse cultivation. Use our tomato selector guide to help you choose which variety to grow.
    • • Sow salad leaves in pots and place on the windowsill or in the greenhouse.


    • in 

the cold frame cloches  In the cold frame/ under cloches


    • • Try sowing lettuce in module trays under glass for transplanting in the garden later. Alternatively sow lettuce outside under cloches.
    • • Sow radish seeds under glass under cloches for your first salad of the season.


    • direct sow outdoors seed packet  Direct sow outdoors


    • • Start sowing beetroot directly into well prepared soil.
    • • Sow broad beans directly into the ground now for a delicious summer crop. If mice are a problem sow into modules for transplanting later on.
    • • Start to sow carrot seeds directly into light, stone-free soil.
    • • Direct sow summer and autumn cabbages such as 'Red Jewel' and 'Greyhound' into well prepared beds outdoors.
    • Chicory can be sown directly into the soil now.
    • Sow herbs such as chives, coriander, dill and parsley directly into the ground or in containers.
    • Calabrese 'Aquiles' can be sown outdoors or into modules for planting out later in the spring.
    • • Create a comfrey bed in an unused corner of the garden to make your own organic fertiliser. Sow into a seedbed outdoors.
    • • For summer crops of kale, sow seed outdoors now in a well prepared seedbed.
    • • For something unusual and fast-maturing try direct sowing kohl rabi outdoors. 
    • • Sow leeks directly into the ground now.
    • • If the soil is workable, direct sow parsnips in rows 30cm apart.
    • • Sow peas directly in to the ground or start them off in modules if mice are a problem.
    • • Start sowing spinach outdoors in soil enriched with plenty of organic matter.
    • • Sow spring onion seeds in drills outdoors for a quick crop to add to salads and stir fries.
    • • Try Swiss chard sown outdoors for a colourful crop - they even look great in flower beds!
    • • For early turnips sow the seed directly into the ground now.
    • • Try growing your own watercress in containers, making sure the container is sitting in 2-3 inches of water at all times.


    • plant outdoors trowel  Plant outdoors


    • • Plant Jerusalem artichoke tubers as soon as the soil is workable, at a depth of 10-15cm.
    • • Plant out asparagus crowns in well prepared permanent beds.
    • • Plant onion sets, garlic sets and shallots now for a crop this summer.
    • • Plant rhubarb crowns into a rich fertile soil.
    • • Plant strawberry plants in the ground now, or in hanging baskets for a pest-free crop this summer.