Horridculture – True Colors

P90821Bearded iris can bloom in almost any color. It is expected of them. There is not much they can do to surprise us.

Dahlias exhibit a remarkable range of both color and floral form. Only a few colors are beyond their range.

Roses, gladiolus, freesias, tulips, hyacinths, petunias, pansies, primroses and several of the most prolific bloomers are expected to provide many choices of color.

Other flowers are not so diverse. Forsythia blooms only in bright yellow, or perhaps a lighter hue of yellow. Mock orange blooms only in white, either single or double. Until recently, before purple was invented, the common species of lily-of-the-Nile were either blue or white. We tend to appreciate such flowers for their simplicity, and do not expect anything more from them.

Decades ago, hydrangeas were either white or pink or blue. I say ‘either’ because what seems to be three choices is actually only two. White hydrangeas were always white. Pink or blue hydrangeas were the same, but were pink in alkaline soil, or blue in acidic soil. Blue hydrangeas planted into alkaline soil turned pink. Conversely, pink hydrangeas turned blue in acidic soil.

In the slightly alkaline soil of the Santa Clara Valley, pink hydrangeas were common. Blue hydrangeas were fertilized regularly with aluminum sulfate or some sort of acidifying fertilizer.

In the more acidic soil of the West Coast of Washington, pink hydrangeas would have been blue without lime.

Some more recently bred cultivars of hydrangea excel at either pink or blue. It does not take much to convince them to exhibit their preferred color in less than conducive conditions. These cultivars made it easier to grow blue hydrangeas in the Santa Clara Valley, or pink hydrangeas on the West Coast of Washington.

Then breeding got ridiculous. Hydrangeas were bred to bloom reliably in rich shades of purple, red, or dark blue, with minimal sensitivity to the pH of the soil. They are appealing to those who like these unnaturally rich colors; but to those of us who expect hydrangeas to bloom in white or traditionally soft hues of pink or blue, they are just too weird.

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Fan Flower

60727Only a few flowers are true blue. A few more are nearly blue, but slightly blushed with lavender. Of the latter group, fan flower, Scaevola albida, which is usually more lavender than blue, can be quite convincingly blue if conditions are just so. The semi-circular flowers (which are actually wide bilateral flowers) are most abundant in spring and summer, but can bloom sporadically all year.

The finely textured evergreen foliage is dense enough to function as light duty groundcover. Mature plants eventually get about four feet wide without getting deeper than a foot, and more typically stay less than half a foot deep. Outer stems pressed into the soil with their tips up should root and grow into new plants. Fan flower prefers regular but moderate watering. Shade inhibits bloom.

Fan flower only became available in the middle of the 1980’s. How appropriate for flowers of such distinctive style and color! The original common type is still the most reliable. Newer cultivars are not quite as resilient, and might not be as vigorous either. However, they are worth growing for their bigger and bolder flowers, and because they cascade better from pots or raised planters.

Mexican Bush Sage

51014In the first year, Mexican bush sage, Salvia leucantha, does not get very big. Then it gets cut back to the ground at the end of winter. It gets about twice as big in the second year, only to get cut back again as winter ends. By the third or fourth year, healthy maturing plants can grow to five feet tall and seven feet wide each season. While cut back, big clumps can be divided to propagate.

Strikingly purplish blue floral spikes bloom from summer or early autumn until frost. The odd white ‘tags’ that protrude from the fuzzy bracts are the true flowers. The lanceolate leaves are grayish sage green and somewhat fuzzy. Plants are well rounded like tumble weeds, and should not be shorn. Mexican bush sage is very popular among hummingbirds, butterflies and bees.

Mexican bush sage wants full sun exposure, and unlike most other sages, it prefers relatively rich soil. Fertilizer can compensate for inferior or dense soil, and improves foliar density, but too much can delay bloom. New plants like to be watered regularly, especially if they grow well. As they mature and disperse their roots, they become less reliant on regular watering.

Blue Marguerite

60907Most blue flowers are blushed with purple to some degree. Except for lily of the Nile, true blue flowers are quite uncommon. Even with their yellow centers, the tiny daisy flowers of blue marguerite, Felicia amelloides, seem to be too blue to be real. They are almost expected to fade to lavender. Bloom may not be as full as it was a month ago, but continues as long as the weather is warm.

Mature plants are usually less than a foot and a half tall, and not much wider, with a symmetrically rounded form. The branches are rather fragile, and can be broken by something as trivial as a clumsy cat. They really are not strong enough for bouncy dogs or children. Yet, their tiny oval leaves are just raspy enough to deter deer. Unfortunately, blue marguerite plants live only a few years.

Nierembergia

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When first created by Chrysler, the Imperial was considered to be so close to perfection that fancy colors were unnecessary. It was originally only available in black or white, and later red, like the Chrysler Imperial rose that was named for it. It took a while for other colors to become available. Perhaps perfection is the same reason why nierembergia is only blue or white, or maybe purple.

Nierembergia is most popularly grown as a warm season annual for color from the middle of summer to autumn. It can get half a foot high and a foot wide. As a perennial, it has the potential to get twice as high and wide after its first year, but it lasts only a few years, and looks rather shabby through cool winter weather. The small flowers are evenly dispersed over the finely textured foliage, lacking only on the shaded sides of the densely rounded plants.

Because it gets a bit deeper than most other annuals, nierembergia is a nice transitional plant between lower annuals that might cascade over the edge of a planter in front, and higher or more upright perennials or shrubbery that might obscure a foundation behind. It can work alone too, but does not cascade from planters, big pots or hanging baskets.

 

‘Big Blue’ Sea Holly

70719This 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!

Blue Plumbago

70712The 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.

Rounded trusses of small blue flowers begin to bloom sporadically by the end of spring, and continue to bloom in phases until late summer. Supposedly, each subsequent phase should be a bit more profuse than the previous; but not all plants are aware of this. They might bloom best in mid summer, and less profusely later. ‘Alba’ blooms white. Pale foliage indicates a need for fertilizer.

Blue plumbago is not as easy to work with as it seems to be. Once established, it can grow like a weed, and really seems to take care of itself, and it is probably better to allow it to do so. It does not like to be shorn into hedges or geometric shapes as it so often is. Shearing ruins the natural form, eliminates most of the outer canes that provide bloom, and exposes sparse interior growth.

Hydrangea

80711There 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.

Most of the modern cultivars nowadays are better at one color or the other. Those that want to be rich pink or almost red might turn lavender or purple in acidic soil. Those that want to be rich blue might do the same in alkaline soil. That makes for many hues of pink, blue, lavender and purple. Most of those that bloom white always bloom white, and their foliage might be a little lighter green.

There is also much more variety in floral form than ever before, although all bloom in summer or autumn with big rounded or nearly spherical trusses of many small flowers. The deciduous leaves are about six inches long, and pleasantly lush and glossy. Modern compact cultivars stay low and dense. Larger cultivars get about six feet high and wide, with somewhat open branch structure.

Periwinkle

70503Like so many of the easiest to grow plants, periwinkle, Vinca major, is too easy to grow. It has become an invasive exotic (nonnative) weed in many moist riparian environments. It can get rather weedy in home gardens as well. This can be an advantage if it happens to fill in for bald spots in areas of other ground cover. It is a disadvantage if it overwhelms or competes with other plants.

It is hard to believe that such a seemingly innocent plant with sporadic but delightful light blue flowers amongst rich green foliage has such unpleasant potential. The radial flowers are about an inch or maybe two wide, and bloom almost all year except for winter. The simple evergreen leaves are likewise an inch or two long. The wiry stems stand a foot or two high before flopping over.

Once stems lay down, they develop roots where they touch the ground, and form new plants that repeat the process of producing upright stems that flop over. Without confinement, there is no limit to the trouble they can get into. Fortunately, it is not a fast process. Cultivars with white or purple flowers, or variegated foliage are more complaisant. Periwinkle is neater if mown as winter ends.

Forget-Me-Not

80418It is not easy to forget annual forget-me-not, Myosotis sylvatica. Even if it dies back early in the heat of summer, it will probably throw plenty of seed to regenerate through next winter, and bloom again by next spring. It can easily naturalize in damp or riparian areas, and might be considered to be a weed; but like nasturtium and foxglove, it is a polite weed that is not aggressively invasive.

The tiny blue flowers start to bloom while winter is still cool, and then get a bit more abundant as the weather warms in the beginning of spring. Some modern garden varieties bloom with pink or white flowers. Tender leaves are about two or three inches long, and less than an inch wide. Soft stems creep laterally, but do not get far. Mature plants are less than a foot tall, and two feet wide.

Between autumn and early spring, seed can be sown directly where plants are desired. Because they are so tender, plants are not often available in nurseries. Forget-me-not is a nice understory plant to larger rhododendrons and up-pruned shrubbery, or covering for daffodils, freesias and other spring bulbs. They want regular watering and rich soil, and can be happy in cool partial shade.