Well actually, yes, but it all depends on what we mean by an ephemeral perennial. Ephemeral things (from the Greek, ephemeros – literally, lasting only one day) exist only briefly, such plants may be short lived or flower only briefly. When we first become interested in gardening and start trawling books for inspiration long lists of must-have plants begin to be made. Photographs tempt us down many paths and over time we learn what grows well for us and what does not. Some plants fall by the wayside simply because they flower so briefly or die out during their first winter while others become the mainstays of our planting pallet.
Cold season annuals like nigella and clarkia may fall into this category, but I couldn’t garden without them; Iris chrysographese with nearly black flowers cannot be resisted even though the flowers are gone no sooner than they appear which is the same as with Paeonia mlokosewitschii the ravishing species Christopher Lloyd told us “flowers for about five days in early May, and is at its most ravishing best for about four hours in the middle of this period”. Of course we should grow such gems and relish them all the more for their transience, but we cannot rely upon them to build a complete garden picture; these are the icing on the cake – plants that fall into a group I have come to call complementary plants.
Transience is sometimes an asset and not to be scorned; I am thinking of oriental poppies. Their fist sized blooms explode into vivid blobs of colour in our gardens in late May. The tulips have done their thing by this time and it is still early for many of our mainstay perennials. Lights, music, action – the oriental poppies are ready to take centre stage. A week is enough of all this excess, were it to go on longer it would certainly begin to grate and once these perennials have done their thing we can cut down their bulky foliage to give space for neighboring plants to take their place.
In developing my ideas for perennial meadows it was soon apparent that I needed to use additional plants to support my main theme plants in order to contribute something to the scene either earlier in the season or sometimes later. This has become the main focus of complementary plants in my schemes and this is where the so-called ephemeral perennials have found their place.
The criteria for selecting these complementary plants is not difficult to grasp. Essentially they are there to support rather than hold centre stage and so must not displace the theme plants. For spring the most important group must be bulbs, and my preference goes always to tulips. Such perennials easily slot in between the theme plants and after contributing their flower display rapidly disappear from view.
Over the years I have also trialled other perennials with various degrees of success. Many have been woodland species, their ephemeral nature arising from a need to grow quickly in spring to take full advantage of available light and moisture before the overhead leaf canopy closes. Many are worth perennials, but don’t posses the visual impact or vigor to flood the meadow with either their foliage impact or flower colour; for example, different species of cardamine, including the showy C. quinquefolia have survived and flowered for years. Other species might be considered too vigorous to be included such as Ranunculus ficaria, but I use R. f. ‘Brazen Hussy’ with its brassy yellow flowers highlighted by the purple black foliage amongst tall growing grasses and late season perennials without any problems.
An excellent ephemeral to use in a perennial meadow is Mertensia virginica (M. pulmonarioides) which has juicy glaucus foliage and fresh sprays of light blue flowers. It dies down completely after flowering. It will not thrive in dry situations and can be short lived, but in the right setting it will set seed and maintain itself so long as you don’t weed them out.
Behaving in a similar way, Geranium tuberosum, is most effective in creating a delicate green carpet of foliage that will cover the planting area long before the theme plants start into growth. The sprays of small, blue, typical geranium flowers appear in late spring, but don’t last long, however, by that time it will have served its purpose. This is a robust and excellent addition in many different schemes of mine.
The final plant worthy of a mention in the context of a complementary perennial – as I do not think it is good enough to play the role of a major theme plant in any border, is Thermopsis villosa. This is a slight, yellow flowered lupin-like plant that has the reputation of spreading by an underground running root system. This characteristic might be typical of many unwelcome weeds in our borders, but in this case the plant is not aggressive. The slim stems arise amidst its neighbors in early summer and like the brash oriental poppy can liven up a scheme in that difficult period between spring bulbs and high summer perennials sometimes named the June gap. If you get two weeks of pretty yellow flowers from this ephemeral perennial you can consider yourself lucky, but as with so much in gardening timing is everything.
Books and especially web blogs tempt us to grow many lovely plants, but it is only in combination with others that we can use them to create satisfying garden effects. By all means collect plants for their own sakes, but you will get far more pleasure from them when you find a worthy use for them and that is always the way I have learnt look at any new plant I encounter.