Have you ever noticed how many of the flowers we rely on for a late summer display tale the form of a Daisy? Although daisies are one of the most familiar flower forms that we see from the small native Lawn Daisy (Bellis perennis) to the tall Sunflower (Helianthus annuus) the flowers themselves are most definitely worth a closer look. The ‘flower’ is in fact a collection of dozens or sometimes hundreds of tiny individual flowers that make up the centre, surrounded by a ring of ‘ray’ flowers that are adapted and look like the long outer petals. Each floret is pollinated and produces a seed resulting in huge numbers of seeds from a single flower head and the clouds of airborne seeds from Dandelions and thistles.
Well that is enough botany; the interesting question is why are our late summer borders full of this family? Of course not everything in the Daisy family flowers from July to September but there are an awful lot that do: Sunflowers, Echinacea, Rudbeckia, Helenium, Michaelmas Daisies, Argyranthemum (Marguerite), Aster which gives the whole family its name, Dahlia, Chrysanthemum, Cosmos, Gaillardia, Gazania, Shasta Daisy, Osteospermum, Zinnia.
One reason is simply that the Asteraceae family contains approximately 10%, more than 20,000, of all flowering plant species (including those that are not remotely decorative) so merely on the grounds of probability we grow many Daisies. To understand why there is a predominance of late flowering we need to look at where these plants come from or in the case of cultivated varieties that only exist in gardens, where the ‘species’ version grows naturally. Think of the species plant as the original cousin of the cultivated garden varieties. The flowers may be bigger or different colours but the growing conditions will be similar. Most Asteraceae originate from desert or semi-desert climates in tropical and subtropical regions (notably in U.S.A., Central America, eastern Brasil, the Mediterranean, southern Africa, central Asia, and southwestern China. What does this tell us? Well in general these areas have longer and hotter summers than the UK and whilst those from North America and China will survive winter temperatures, all need a long period of above freezing temperatures to grow, mature and flower. The result is that they do not start to flower here until past mid summer.
Additionally, most plants that originate from the regions where there is no frost such as South Africa, Brasil and Mexico are described as half-hardy in the UK. Commonly annuals grown from seed, like Cosmos and Zinnia, they are started under cover or sown in April again meaning that flowering does not start until July.

So next time you admire the blaze of colour in a late summer herbaceous border, do not dismiss the humble daisies.  Take a moment to examine the structure of each flowerhead, appreciate the pollen and nectar that they supply to bees and butterflies and marvel that these plants from warmer climes give us such a long and welcome display in the ever unpredictable UK weather!

And as the weather cools again in October, we enter the ideal time for planting or dividing and replanting perennials.  Many of the Daisy family create loose clumps of shoots joined together by short underground stems that bear clusters of roots.  So although they may spread quite quickly and fill the space over 2-3 years, they are very easy to split.  Either dig out a small section from around the edge or lift the whole clump, divide it into pieces and replant the younger outside sections to replace the older centre.  If you have spotted a large patch of Daisies that you like in a friend’s garden, why not offer to lift and split it so that you both benefit?

Happy Gardening from Alison