September 23rd, 2016 | Plant Talk with Graham Rice | 0 Comments
Hardy annuals are exactly that: they’re hardy and they’re annuals. So we tend to assume that we sow them in spring, they flower in summer and they die at the end of the season and produce. Well, not quite… In nature, in their wild habitats, many hardy annuals behave rather differently.
The point is that many annuals grow in areas where the summers are hot and dry – like the Mediterranean region. If the seeds germinate in spring, there’s not much time for the plants to develop before flowering. So they germinate in autumn instead.
Well, to be more precise, in many species the seeds have a built-in genetic variability: some will germinate in autumn and some in spring. That way, if the autumn seedlings are lost for some reason, grazing perhaps, there are still some seeds to germinate in spring and produce at least a few seeds to carry the plant into another year.
But here’s the thing. Hardy annuals which germinate in the autumn have time to develop, they start to get their roots down before winter, they make rosettes of foliage and will continue to develop in mild spells during the winter.
The result, of course, is that by the time you’d normally be sowing seeds in March or April, the autumn sown seeds have already developed into sturdy plants which make larger plants by flowering time. These larger plants flower earlier, for longer and their deeper roots are better able to withstand the drier summer weather when it comes.