This one is no fun to handle. It is just as prickly as it looks. Yet, it is the spiny foliage and blooms that make ‘Big Blue’ sea holly, Eryngium X zabelii ‘Big Blue’, so appealing. The knobby blue thistle flowers are centered on prominently flaring grayish blue bracts that look like metallic snowflakes. The intricately lobed grayish foliage contrasts splendidly with just about any darker green foliage.
Bloom begins with summer and continues almost to autumn. The first flowers are solitary on strong stems. As they fade, sideshoots from these original stems continue to bloom with smaller but more abundant flowers. They are excellent cut flowers, fresh or dried. However, cutting the first solitary flowers with long stems removes some of the sideshoots that would otherwise bloom later.
Mature plants can get three feet tall and half as wide. Shade, even part shade, causes irregular growth that can be quite weedy. Although perennial, ‘Big Blue’ sea holly might live only a few years.
Contrary to the appearance of the bristly thistle like foliage and flowers, sea holly is in the Umbelliferae family, which means that it is more closely related to celery and carrot than it is to artichoke!
It was probably a good idea when it was introduced to California, but fountain grass, Pennisetum setaceum, became too much of a good thing for a few temperate regions in which it naturalizes and displaces native vegetation. Although it now works to inhibit erosion where it grows wild on the embankments of highway interchanges, it must sometime be mown because it is combustible.
The delightfully clear sky blue flowers of blue plumbago, Plumbago auriculata, seem like they belong with colorful annuals or in a tailored border of colorfully blooming perennials. However, the rampant canes of mature plants are really best in the background where they have room to grow wild. The canes do not climb like vines, but can flop over other shrubbery as high as fifteen feet.
It is a common theme. Coreopsis was a much simpler group of only a few specie and cultivars in the 1980s. There are now too many hybrids and cultivars to keep track of. They have been bred so extensively that they do not produce viable seed like the old fashioned types that can self sow so nicely, and were more closely related to the unimproved specie that would be found in the wild.
Once it gets started in late spring, ‘Mystic Spires Blue’ salvia has potential to bloom until autumn. It only needs older floral spikes pruned away as they fade (deadheading) to stimulate new bloom. If it gets overworked and lanky without deadheading, it can be cut back in the middle of summer to start a new bloom cycle all over. It can get more than three feet tall and almost three feet broad.
There are so many more of the fancier cultivars of hydrangea, Hydrangea macrophylla, than there were as recently as the 1990s. Many of the pink and blue hydrangeas were interchangeable years ago. They would bloom blue if the soil was acidic. They would bloom pink if the soil was alkaline. Their color changed accordingly when planted from potting media into soil of another pH.
Compared to crape myrtle, sycamore (London plane) and many other more popular trees, the beech, Fagus sylvatica, is much less problematic, and really deserves more respect. Although it can eventually get almost as big as sycamore, it has remarkably complaisant roots. It is neatly deciduous, defoliating only in autumn, without noticeable floral mess. Disease and pests are rare.
The native American coneflower, Echinacea purpurea, of the Midwestern prairies has been popular within its native range longer than anyone can remember, and has become more popular in the West as extracts of echinacea became a fad in herbal medicine several years ago. Modern garden varieties and cultivars have been bred and hybridized for larger and more colorful flowers.
Pink, red or white are the only choices. There happens to be a darker shade of red. Yellow throats are more conspicuous in white flowers. Otherwise, there is not much variation of color amongst the various mandevillas. The flowers are very similar in both color and form to those of related oleander, but are larger. Some are as wide as three inches. Small flowers can have pointed petals.
It is considered to be an Italian herb, but since it was popularized in America in the late 1940s, oregano, Origanum vulgare, has become more popular in Italian-American cuisine than it is in Italy. It is now the traditional ‘pizza herb’ for American style pizza. Oregano happens to be one of the few herbs that is preferred dried rather than fresh. Only foliage is used, either before or after bloom.