Unfortunately, some unimaginative horticulturists coined the common name “blue spirea” for this excellent small shrub.
In so doing, he unwittingly did the plant a disservice, and the name immediately identified it with the ubiquitous Spiraea x Vanhouttei, which is, perhaps, the most common shrub to be found in the garden and landscape plantings of America.
Blue Spirea
“Blue spirea” is not spirea at all. It does not belong to that family of plants but to the verbena tribe. “Shrubby verbena” would have been a much happier choice of name for this garden ornamental.
Therefore, let us ignore the misnomer “blue spirea” and call it by its proper name, caryopteris (pronounced carry-op’-ter-is).
Here is a shrub made to order for the soils and climate of the Great Plains. It takes the cold, drought, heat, and everlasting wind that buffet our gardens in stride. It is quick to grow and produce its long sprays of blue flowers.
Plant it in the spring, and you can be sure that late July and August will bring willowy sprays of soft blue flowers to brighten the garden and provide material for cutting. These sprays are an arranger’s dream.
Even the fruiting stems after the flowers have faded are good arrangement materials. Also important is that caryopteris is happy in high lime soils where true spireas turn sick and yellow with iron deficiency.
Best-Known Blue Mist
At present, the best-known caryopteris is ‘Blue Mist.’ This variety name is a good choice.
Blue Mist grows to 4′ feet and makes a bush up to 6′ feet across. It is never leggy or straggling. It is covered with lacy blue flowers in sprays 12″ to 20″ inches long in late July and August.
In addition to ‘Blue Mist,’ there is a newer one called ‘Azure.’ This was bred at the Cheyenne Horticultural Field Station, Cheyenne, Wyoming, where growing conditions are rough. It is a seedling of ‘Blue Mist’ but is even harder.
The plant is smaller than its parent, the flowers are a little deeper blue, and the foliage is darker green. ‘Azure’ is perhaps the better plant for the low lines of the modern home.
Both varieties are good plants for any garden, particularly for difficult locations where they thrive despite the wind, drought, and poor soil.
Ideal Planting Conditions For Caryopteris
Plant caryopteris in full sun if possible, although the plants will tolerate shade during the day.
The plants should be cut back to 6″ or 8″ inches each spring to ensure a maximum of the long sprays that are their chief attraction.
The shrub is short-lived compared to lilacs and others of that class, but it is so easily propagated that anyone can increase it.
Three Inch cuttings of new wood taken in early June will root in days and, if given a forceful culture, bloom in September.
Such cuttings are best started in sand or perlite, but even those stuck in the soil and kept shaded and moist will root in appreciable numbers.
Incidentally, caryopteris is easy to grow from seed. Seedlings, by the thousands, will come up each spring around the mother plants and are as easily transplanted as cabbage. Seedlings do vary, but most of them are pretty good.
44659 by Glenn Viehmeyer