CUSTOMS HOUSE: Of big blousy blooms and half-hardy annuals

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THE big, blousy Bet-Lynch-style show-stoppers in the annual garden are, more often than not, half-hardy types.

Sometimes they’re tender perennials in their home lands, like dahlias – you can usually spot them, as they’re the ones being sold as plug plants in catalogues and garden centres, costing a small fortune.

Here’s the most popular half-hardy annuals that can be sown now; Salvia splendens, Lobelia, Zinnia, Cosmos, French/African Marigold (Tagetes), Dahlia, Nicotiana (tobacco plant), Antirrhinum (Snapdragons), Annual Rudbeckia, Busy Lizzie (Impatiens), Phlox drummondii, Mesembryanthemum (Livingstone daisy), Heliotrope (Cherry Pie), Nemesia, Gazania, Ageratum, Osteospermum, Verbena x hybrida, Petunia and Salpiglossis.

They all need a long season to flower well, which necessitates indoor sowing in a propagator sometimes as early as January (Antirrhinums), but more usually February/March.

What is critical here is light intensity. If you don’t have a brightly-lit place indoors, wait until March. Warmth and poor light will lead to leggy, weak seedlings which will easily fall victim to disease.

A propagator with a constant temperature is a good buy too. Bear in mind how much plug plants cost, and it will soon pay for itself.

What they all need is good seed compost – buy the best you can afford. Some people like to cover seeds with Vermiculite or Perlite instead of compost – use what you know best. (I find the latter two don’t form a crust which is hard to wet, which is why I use them).

Make sure the soil is watered before you sow and doesn’t dry out. Sealing trays/pots in cheap freezer bags works well.

For detailed instructions for each flower, log on to!half-hardy-annuals/c1kuy for germination temperatures and times, sowing depth, and any special instructions.