But, deep down, we really expect most flowers worth their place to bloom for a long time, and are mightily miffed when they go over more quickly than we think they should, as they have a habit of doing.
The length of time for which a plant produces flowers is influenced by several factors: it may be programmed genetically, it may be influenced by climatic conditions like wind, rain or hot sun; or, even more commonly, it may depend on the availability and success of pollinators. At the risk of stating the blindingly obvious, plants do not flower for our benefit but for their own survival and their evolutionary destiny is wrapped up in how quickly they can get the business of fertilisation and setting seed over and done with.
It is not true to say, however, that there is nothing we can do to influence the length of the flowering periods of many plants. Take the delphinium as an example. If you cut back the developing shoots of some plants in late spring, you can delay flowering by several weeks and so stagger the blooming of the whole group.
Moreover, if you cut off the earliest flowered shoots of phlox, as soon as they fade, the sideshoots will grow up to take their place and flower in their turn. Anyone who assiduously trims their garden pinks, herbaceous geraniums and Salvia superba after their flowering in June should now be enjoying a bonus of late summer flowers. This late blooming is not as generous as the first floraison, it's true, but it is a great deal better than nothing at all.
Another wheeze worth trying with hardy perennials is to divide and replant them in spring, because young plants will tend to flower for longer than old, established ones. It is the old, old story of youth wishing to party the summer away, rather than go to bed nice and early, as their elders do.
Extending the flowering period a little can be helpful, but what we really crave are hardy plants which naturally flower for a long time so that we can use them as sheet anchors to secure our summer colour schemes. These are plants which can be depended upon, year in, year out, to flower for weeks, even months on end, so that they always coincide with their neighbours' flowers, and never miss out because the weather has brought them unseasonably early into flower or has maddeningly delayed them. It is perfectly reasonable, and sensible, to wish to plan our gardens to contain a proportion of these plants.
In fact, this is such second nature that we often choose on this basis without really thinking. It explains much of the popularity of modern roses. It is a fact that they flower twice, in summer, which makes them so desirable and, it must be said, makes us so ungratefully discontented with other beautiful summer-flowerers, such as Philadelphus and Deutzia, which do not. Indeed, if we gardeners had our way, roses would not even pause for breath but would go on belting out the blooms solidly from June to December.
There are plenty of plants with as much, or even more, stamina and faithfulness as roses, yet these do not always get the praise they deserve for such sterling qualities. In the mixed border, I think there should always be a place for the real stayers, like Gaillardia, Penstemon, Erigeron, Scabiosa caucasica `Clive Greaves', shrubby Potentilla and, stoutest of all, the Anthemis family.
The best known of these pretty, single-flowered members of the daisy family is Anthemis punctata var. cupaniana, which combines grey-green filigree foliage, a neat ground covering habit, and attractive and freely- borne white flowers with yellow centres.
It flowers most magnificently in the late spring, but has a way of going on and on into summer and when, finally, you feel it is past its best, if you take the trouble to deadhead it, you will get autumn flowers as well.
I reserve a special place in my heart, however, for the forms of Anthemis tinctoria such as `EC Buxton' `Susannah Mitchell' and `Grallach Gold' because their yellow flowers begin in June and do not lose their appealing fresh-petalled look until the dog days of late August.
They begin to flower later than A. cupaniana but go on for longer and the colours fit into both cool blue colour schemes and hot orange and red ones, which is quite an achievement in itself. They also make quite excellent cut flowers.
`EC Buxton' and `Susannah Mitchell' only grow to a foot (30cm) or so, so are ideal for a border edging. The flowers of the former are a lovely lemon-yellow, and of the latter a creamy primrose. `Grallagh Gold' and `Wargrave' variety are taller, growing to 3ft (90cm). The former has bright golden-yellow flowers, while the latter is paler than `EC Buxton'.
These Anthemis do need some very discreet staking because in rough weather in early August (such as we have experienced this year) they fall over backwards, exposing their middles and losing something of their dignity.
They should also be cut back after flowering is finally over; so that they have the time to grow nice young basal shoots to brave the winter weather. Otherwise you are rather chancing their survival by leaving the older, more woody and, therefore, tenderer stems. Some people take cuttings about now, against the possibility of a hard winter, but in my reasonably cold garden (admittedly in a free-draining soil in sun) they have survived several years unharmed.
If you know someone who grows any of the choice varieties, beg some cuttings in spring. They are a doddle to strike then and will flower well the following summer Alternatively, use the outside fringes of the plant as divisions. I find this keeps them flowering well. It's the least that I can do for plants which give their all through much of the summer.