Annuals are not always true to their name as many which we grow from seed each year are in fact perennial plants that originate from warmer climates than our own. True annuals are often more delicate, etherial and ephemeral elements in our gardens and I would encourage everyone to grow at least some every year – Nigella, Clarkia, Limnanthes and Nemophilla are just a few of my many favorites.
The tender perennials we can grow as annuals are some of the most useful as they have the ability to not only flower over a long period, but their adaption to warmer temperatures often means that they can cope with the heat of summer better; of course I am generalising here. Some of the most useful are Salvia farinacea, Petunia, Begonia, Impatiens and Lobelia.
Growing your own from seed is not difficult, but the drawback with this second group of annuals is that many take a very long time to mature and start flowering. Last year I grew a wide range of annuals, both hardy and half hardy, but my greatest problem was with one of the most useful – Salvia farinacea ‘Victoria’. Sown indoors on the 19th of February they germinated well and were grown on under cover until the middle of May when it was warm enough to risk them outside. Early summer proved to be cool and dry with the result that my small plants grew slowly, getting taller and taller, but not flowering. It was not until mid August with plants much taller than they should have been that they started to flower. Perhaps I should have kept them in the greenhouse until the end of June.
To answer the question posed by this post – yes you can and should consider adding annuals to your perennial borders – but don’t. rely upon them to play a leading role. Some years they will astound you with their vigor and others not.
This year I am taking a rest and will only be growing a few annuals to slip in amongst my perennials. Of these the most important will be Antirrhinum braun-blanquetii, this tall growing species from Spain and Portugal makes candelabras of soft yellow flowers that should have the stature to hold their own in the midst of a perennial border.
Now is the time to get hold of the seeds you need and get sowing; these perennial annuals are well worth the trouble, but apart from the few most popular varieties rarely will you find them for sale in your local garden center.
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