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What s the difference between hardy and half-hardy annuals

01:00 Tue 09th Oct 2001 |

A.� Just about annuals can be sown in spring to give flowers in summer, but there are many that can be sown in autumn, right now in fact, that will survive the winter and be ready to crack on as soon as spring arrives. These are known as hardy annuals.

Q.� But the weather is starting to turn. Why not just wait and put everything out in spring

A.� This is actually a brilliant time to get a range of plants into the ground. The soil is still warm after the summer and before the first frosts.

The great advantage of autumn sown hardy annuals is they have a month or two to make a start before winter sets in. They have time to germinate and produce seedlings. When the weather finally gets too cold growth above ground all but stops, but the root system continues to develop. It means that when the better weather arrives in March and early April they a food gathering network already in place underground and are in a position to kick in straight away.

Not only do you tend to get bigger plants which flower longer and harder than spring sown annuals, but because of their head start they come much earlier, generally by the last few weeks in May. If you leave all that sowing until next year then these annuals aren't going to be in their pomp until July or June at the earliest, and your beds will be left with empty patches all spring.

Q.� How should you prepare the beds

A.� Get rid of any fading bedding left over from this year and put it on the compost heap and weed thoroughly then fork the soil over and rake it to a fine, crumbly texture. Water the beds before rather than after sowing so the seeds don't feel they are being welcomed by a cold shower.

Q.� What about sowing

A.� Don't scatter the seed or you will not be able to tell what is welcome and what is a weed when spring arrives. Sow them thinly in rows 12-15 centimetres apart and keep a note of what went in where.

When they start appearing, thin the seedlings to roughly 8cms apart to give them room to grow on. Come March select the strongest of them and thin them again to a distance of between 12-15cms and top dress with compost or fertilizer.

Q.� Which annuals are hardy

A.� Lots of our favourite cottage garden flowers can be sown in autumn, including larkspurs, Californian poppies, Calendula, cornflowers, marigolds and alyssum. The exceptions include the annual grasses and the sunflower family (helianthus).

Those other great favourites, sweet peas can also be started, but in a long tall pot. Push them in at least an inch and then pinch out the tops as soon as it has two pairs of leaves and keep it somewhere cool light and sheltered over winter.

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By Tom Gard

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