Silver Mountain Gum

Silver mountain gum is remarkably glaucous.

The strikingly glaucous juvenile foliage of silver mountain gum, Eucalyptus pulverulenta, is likely more familiar within floral design than in home gardens. Actually, it is uncommon within home gardens, although quite popular as cut foliage among florists. Its paired and sessile leaves are oval or bluntly cordate (‘heart shaped’), and about an inch or two long.

Adult growth is rare, even among established trees. However, small white flowers bloom from the axils of juvenile leaves that are a year old. (Juvenile growth of most species can not bloom.) Bloom might continue from spring until autumn, as blooming stems sag from the weight of younger distal growth. The aromatic and evergreen leaves stiffen with age.

Low and shrubby specimens with a few trunks may not get much higher than fifteen feet. They have potential to get twice as tall though, particularly if pruned up onto bare trunks. Lignotubers expand below the trunks. Strips of old bark shed to reveal fresh matte brown bark. Incidentally, the Latin name of this species often transposes for Eucalyptus cinerea.

Bismarck Palm

Silvery gray that is almost comparable to blue spruce is even more striking from a palm, like the Bismarck palm.

Most palm enthusiasts believe that the distinguished Bismarck palm, Bismarckia nobilis, is rare because it does not like local climates. It can be damaged by frost in winter, and prefers warmer weather in summer. Another concern is that they get too broad for compact urban gardens, since their shady foliar canopies can get more than twenty feet wide. However, a few seemingly happy specimens are sometimes seen about town.

Foliage of this rare palm is strikingly silvery gray. Green Bismarck palms are even more scarce, both because they are less tolerant to frost, and because they are not so striking. The big and rather rounded leaves are more than six feet wide, and maybe up to eight feet wide, on petioles (stalks) about six to eight feet long!

Mediterranean fan palm

The strikingly silver Atlas Mountain palm.

Not all palms are trees. Some lack trunks, so develop more as shrubbery. Some develop many slender stems, like bamboo. The thin canes of most rattan palms sprawl onto other vegetation for support, as vines. Mediterranean fan palm, Chamaerops humilis, develops multiple stout trunks, but grows so slowly that it can function as big sculptural shrubbery.

Old trunks can eventually get as high as twenty feet, and generally lean randomly. If they get too tall, smaller and more vigorous trunks can replace them. (An arborist can remove the bulky and thorny old trunks.) New trunks develop from basal pups, which can can get too densely foliated without occasional thinning. Removal of such pups might be difficult.

Mature trunks might be as wide as ten inches, with dense coats of basal petiole fiber and thorny petiole stubs. Thorough grooming can eliminate the stubs. However, petioles that suspend the evergreen palmate leaves are outfitted with the same wickedly sharp teeth. Leaves are about two feet wide. Atlas Mountain palm, Chamaerops humilis var.(iety) argentea has strikingly silvery foliage, and grows even slower.

Mexican Snowball

Mexican snowball is strikingly pallid blue.

The silly common name actually suits its plump rosettes of pale bluish succulent leaves. Mexican snowball, Echeveria elegans, forms small colonies that might resemble stashes of snowballs. Individual rosettes are circular, and a bit wider than tall. The widest are four inches or so across. The evergreen leaves are as neatly radial as scales of a pine cone.

Some may know Mexican snowball, and various other species of Echeveria and related Sempervivum, as hen and chicks. Big rosettes can produce so many small pups around their edges that they are reminiscent of mother hens surrounded by their huddled chicks. These pups are quite easy to separate for plugging into pots or elsewhere in the garden.

Mexican snowball is happiest in sunny situations with rather regular watering, but should tolerate a bit of shade and lapses of watering. For small trees in big pots, it can cover the surface of the potting media nicely. Pups plugged into crevices of stone walls might grow into clinging colonies. Tiny pink flowers with yellow tips bloom on wiry stems about now.

Pink Iceplant

Pink bloom is merely a bonus.

Lavender pink bloom in spring or early summer can be profuse in sunny situations. Individual flowers are like small daisies with yellow centers. They stay closed through most of the morning, then open by about noon. If the weather is conducive, they can be slightly fragrant. However, the evergreen foliage of pink iceplant, Oscularia deltoides, might be even more appealing than the bloom.

The plumply succulent leaves are a delightfully bluish hue of gray. With two sides and a flat upper surface, these leaves are triangular in cross section. Blunt foliar teeth provide a distinctive texture. Foliage is so dense that the relatively thin stems within are barely visible. Stems can blush with pink or purple. Bloom is better, and foliage is denser, with good exposure and occasional watering.

Mature growth gets at least half a foot deep, and can eventually get a foot deep. It slowly spreads about two or three feet wide. With age, outer stems develop roots where they lay on the soil, and spread even farther. New plants grow very easily from cutting. Pink iceplant cascades nicely from pots or over stone. It contrasts handsomely with richer or darker colors of other foliage or bloom.

Butterfly Bush

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Garden varieties are less likely to naturalize than the straight species is.

Many plants are so easy to grow that they become invasive weeds. Butterfly bush, Buddleja davidii, has done exactly that in some regions, and is only controlled here by the arid climate. Yet, once established, it does not need much water at all, and can survive on rainfall in some spots. They only want good sun exposure.

Mature plants can get more than 15-feet tall and half as broad, with long arching limbs. Most garden varieties stay smaller, and some do not get much more than six feet tall. The evergreen foliage is sage green, grayish green or chartreuse. The paired leaves are about the size and shape of willow or eucalyptus leaves.

Conical trusses of densely packed tiny flowers that bloom in mid-summer can be various shades of blue, purple, red and pink, as well as dusty white. Some new varieties bloom soft orange or yellowish orange. The more compact and colorful modern varieties are not as fragrant as old classics are.

Catmint

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Catmint is mellow like old denim.

Not to be confused with closely related catnip, catmint is a resilient perennial for sunny and warm spots. Nepeta faassenii had always been the more familiar catmint. Modern varieties include a few other specie and hybrids. The various catmints work like the various lavenders or trailing rosemary, without getting so shrubby.

Unless they lean on something or climb through shrubbery, stems do not often get any higher than a foot as they spread to two or three feet wide. A few stems around the edges can grow roots through winter, to spread more the following year. New plants are easy to propagate by division of some of the rooted stems before spring.

The diagonal flower spikes that bloom most profusely as weather warms in spring are the color of faded blue denim. Some catmints bloom white or pink. The finely textured foliage is grayish green, although some varieties of catmint have chartreuse or greener foliage. Spent bloom can get shorn off to keep new foliage neat.

Silver

P90713KThese are two pictures that did not make the grade for my ‘Six on Saturday‘ post this morning. That post featured bronze and gold foliage. Actually, of the six, only two were bronze, and only one was truly gold. One that I passed off as bronze was more purplish. Two that I thought were gold were just variegated with yellowish green and white.

I am none too keen on bronze or gold foliage anyway. The only exception that I can think of is the old fashioned bronzed ‘Schwedleri’ Norway maple. It was planted as a street trees on a few streets in the Santa Clara Valley in the 1950s.

Bronzed cultivars are less vigorous than their greener counterpart.

Gold cultivars are even less vigorous, and susceptible to scorch.

The best quality about bronze and gold is that they make silver look so good.

Olympic medal designations really should be reconsidered.

I only featured bronze and gold foliage earlier because I liked the contrasts between two different cultivars of each of the three species that were featured. Ironically, none of the three pairs compared bronze to gold directly. One compared purple to gold. The other two compared bronze to variegation that was barely yellow. Oh well.

There are neither bronze nor gold cultivars to compare to the silver foliage of the two species shown here.

I do not know what species of agave this is. There are not many distinguishable features visible in the picture above. The color and texture of the foliar surface might be identifiable to an expert. The little snail does not seem to be at all concerned.

The Eucalyptus cinerea in the picture below was pruned aggressively last autumn, both to contain the disfigured canopy, and also to stimulate more vigorous new juvenile growth. It is now strikingly silver.P90713K+

‘Icee Blue’ Yellowwood

90313No, it is not an oxymoron. ‘Yellowwood’ is the common name for a few specie of Podocarpus. The evergreen (or ‘everblue’) foliage of ‘Icee Blue’ yellowwood, Podocarpus elongatus ‘Monmal’, really is as silvery grayish blue as the name implies. It can be as striking as some cultivars of Colorado blue spruce. It grows slowly in narrow columnar form to only about fifteen or twenty feet tall.

The finely textured evergreen foliage is ideal for both formal hedges and informal screens, although it takes a while to fill in, particularly for larger hedges and screens. Tip pruning of lanky growth of informal screens improves density. The narrow leaves are about two inches long. Fresh new foliage may be lighter and very slightly greener, which can contrast nicely with more mature foliage.

‘Icee Blue’ yellowwood will tolerate a bit of partial shade, but exhibits the best color in full sun. It prefers to be watered somewhat regularly while getting established. As it matures, it becomes less reliant on watering. Like many other Podocarpus, it is susceptible to infestation by scale insects and the ants that cultivate them. Scale produce sticky honeydew which blackens with sooty mold.

‘Little Ollie’ Olive

60302Those of us who appreciate olive trees for their fruit production or distinctively gnarly trunks probably would not understand the popularity of the Little Ollie olive, Olea europaea ‘Little Ollie’. Not only is is completely fruitless, but it lacks sculptural trunks and limbs. It is instead a short and and shrubby plant that gets only about three or four feet tall, with very dense grayish green foliage. Only the narrow evergreen leaves are recognizable as those of an olive tree.

Little Ollie olive behaves something like boxwood, and does not grow much faster. It can even be shorn as a hedge or topiary. It is quite resilient to heat and harsh exposure, and once established, it does not need much water. Because it is so compact, and has such resilient roots, it is popularly grown in large urns or planters. The grayish foliage is a nice backdrop for more colorful annuals and flowering perennials.