Rose Campion

80606Rarely planted but often found where the wildflowers grow, rose campion, Silene coronaria, has a way of sneaking in like California poppy or sweet alyssum do. It is so rarely planted that young plants are rarely available in nurseries. Seed is somewhat more available in nurseries, and quite available online. Although they self sow freely if allowed to go to seed, they are not really invasive.

The velvety gray foliage is pretty alone, and becomes a perfect backdrop for the surprisingly bright magenta, regal red or pure white flowers that bloom through early summer. Most of the foliage forms low mounds not much more than a foot wide, while flowering stems stand almost twice as tall. Flowers are ideal for cutting. Hummingbirds enjoy magenta and red flowers more than white.

Individual plants can last for a few years as short term perennials, but because they seed profusely enough to replace themselves annually, they are often grown as annuals, and pulled up before new seedlings appear. Those who last for a second year should probably be groomed. If seedlings are crowded, some can be pulled up and relocated while young. Rose campion wants full sun.

Clematis

70524There are so many different specie involved with the extensive breeding of the modern cultivars of clematis that they are not even assigned full Latin names. They are simply known as ‘clematis’ (without a specie name), with a respective cultivar name. Clematis X jackmanii is the oldest known hybrid, so the name is often applied to other hybrids, whether or not they are actually related.

The big broad flowers are abundant and spectacular this time of year, but unfortunately do not last long. Bloom finishes before the weather gets much warmer, leaving unimpressively rustic foliage on wiry vines. The vines might reach ground floor eaves, and are just the right size for small gate arbors. If necessary, old plants can be lightly groomed of twiggy growth while bare through winter.

Flowers are rich shades of blue, purple, red, pink or white. Many are bi-colored, and some have ruffled centers. During full boom, there may be more flowers than foliage visible. Foliage is a dark shade of olive green, with a dull matte finish, which is actually a perfect background for the rich color of the bloom. Roots like rich, moist and cool soil, while the vines climb into sunnier situations.

Cherry Laurel

80530There is a reason why the most popular specie for frequently shorn formal hedges have small leaves and finely textured foliage. Technically, a formal hedge of cherry laurel, Prunus laurocerasus, can be shorn as well, but should be shorn only once or twice annually, and then allowed to fluff back out. Otherwise, the big leaves get shredded as quickly as they recover from previous shearing.

If pruned more frequently, hand pruning works best, and is not as tedious as it sounds. Informal pruning is even easier, and is done primarily to prevent hedges from getting to deep (from front to back), and to prevent individual shrubs from dominating or subordinating. Pruning also eliminates most of the abundant summer bloom of upright trusses of thirty or so tiny creamy white flowers.

Cherry laurel is densely foliated and quite stout, even without shearing or pruning, and can eventually but rarely get thirty feet tall! The glossy evergreen leaves are about three inches long. There happens to be a few cultivars, including one that is variegated with light yellow, and others that are compact dwarfs. (Prunus caroliniana is different species that is also known as cherry laurel.)

Wax Privet

70517The pros and cons of wax privet, Ligustrum japonicum ‘Texanum’ might get it a rating of about 2.5 out of 5. It seems that every asset is offset by a liability. The profuse clusters of tiny white flowers are sweetly fragrant, but are also a serious problem for those allergic to pollen. The berries attract birds, but are also very messy, and contain seeds that can germinate in the strangest of places.

The dense evergreen foliage is prettier and actually glossier than that of the more common glossy privet. Growth is slower, and therefore easier to maintain as a shorn hedge. Regular shearing deprives wax privet of most, but not all of its bloom and seed. Glossy privet is more invasive if allowed to set seed, but less invasive as a shorn hedge deprived of bloom before producing seed. Without shearing, wax privet eventually reaches ground floor eaves, and gets about half as broad. It can be groomed into a small tree.

Unwanted feral seedlings should be pulled as soon as they are detected. If cut instead of pulled, they are likely to regenerate, and will be impossible to pull the second time around. Roots are rather greedy.

Snapdragon

80523They are short term annuals in spring or autumn. Where winters are cold, they may last from spring through autumn. Where summers are hot, they may last from autumn through spring. So what are snapdragon, Antirrhinum majus, here? They can be either or both, depending on where and when they get planted. For most of us, they are a cool season annuals that finish before summer.

Although they prefer to be in full sun, the warmth of such exposure is what limits their practicality through summer. They bloom a bit less in partial shade, but are more likely to last through summer if kept cool, particularly in an innately cool microclimate. Like many annuals, they want rich soil, and regular watering. Because they are susceptible to rust and mildew, foliage should be kept dry.

Snapdragon blooms in white and many cheery hues of yellow, orange, red and pink. Some of the older varieties, particularly those developed for the cut flower industry, can get very tall, and might almost reach low eaves! Modern garden varieties are shorter and fluffier. The biggest are less than four feet tall, and less than a foot and a half wide. Deteriorating flowers should be pruned away.

Mirror Plant

70510As the old fashioned larger mirror plant, Coprosma repens, fell out of favor through the 1990s, several more colorful varieties of a more compact species of mirror plant, Coprosma X kirkii, became popular. (The ‘X’ in the name indicates that it is actually a hybrid of two specie.) Without getting much more than two feet deep, it spreads out laterally like dense evergreen groundcover.

The color is not from bloom, but from the very glossy foliage. It can be variegated with white, gold, red, pink or bronze, or completely brownish bronze. Some varieties stay very shallow. Others can be shorn into low hedges like Japanese boxwood, only shorter. Although mirror plant does not mind partial shade, foliar density and color is best with full sun exposure and occasional watering.

Most modern varieties are known by their cultivar names, without their specie names. For example, Coprosma ‘Tequila Sunrise’ lacks the species name of ‘X kirkii‘. Such omissions might be the result of confusing hybridization with Coprosma repens, for rounder leaves. In other words, some cultivars may be of ‘questionable parentage’. Some are just dwarf cultivars of coprosma repens.

‘Emerald Green’ Arborvitae

80516The many cultivars of arborvitaes of home gardening have been so extensively bred and selected that only the foliar texture resembles that of their ancestors. ‘Emerald Green’ which is also known by its Danish name ‘Smaragd’, is a cultivar of arborvitae that was developed from the white cedar, Thuja occidentalis,which grows wild from Minnesota to New Brunswick, as a forty foot tall tree!

‘Emerald Green’ grows quite fast while young, but should get no taller than about fifteen feet, and no wider than about four feet. It is one of the best columnar arborvitaes for tall hedging. Although they can be shorn, they are so dense and uniform that they are at their best if only occasionally trimmed of stray stems, or to keep taller specimens from getting too much taller than shorter ones.

The tiny evergreen scale leaves are tightly arranged on vertically arranged flat foliar sprays. Foliage is quite dense, and softer than that of most other conifers. A bit of shade is tolerable, but too much compromises foliar density. Bloom is barely noticeable, and seeded cones are not much to look at. The shaggy ruddy brown bark is handsome but seldom seen on well foliated specimens.

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.

Avens

80509Wow, this is quite old school. Is it making a comeback? That would be nice. Avens, which is also known as Chilean avens, Geum quellyon, is an old fashioned perennial relative of the strawberry. Instead of producing fruit, it provides handsome yellow, red or coppery orange flowers that look something like small single, semi-double or double anemones, but can bloom through most of May.

Although perennial, avens do not last forever without some degree of help. After the first season, most of the slightly ruffled and hairy foliage dies down during the colder part of winter. New foliage and bloom develop in spring. After the second or third year, and every few years afterward, mature plants should be divided before or after bloom. Pups are more vigorous than the parent plants.

Happy avens gets as high and wide as a foot and a half. Much of the height is in the branched floral stems, which might need to be staked if they get too heavy with bloom, or are in a breezy spot. Most of the mounding foliage is basal. A bit of shade is tolerable and actually preferred to hot situations. Soil should be rich and well drained. Avens plays well with others in mixed perennial beds.

Wisteria

70426The popular wisterias that bloom so profusely before their new foliage appears in spring are Chinese wisteria, Wisteria sinensis. Others specie are rare. The impressively longer floral trusses of Japanese wisteria are not as abundant, and bloom late amongst developing foliage. American and Kentucky wisteria are more docile small vines, but their floral trusses are both short and late.

Chinese wisteria is also the most fragrant and the most colorful of the wisterias. Lavender is still the most popular and traditional color. White, pink, sky blue and darker almost purplish lavender are also available. The floral trusses, known as racemes, get from half a foot to two feet long. Double flowered cultivars never became too popular because the fluffier blooms are not as elegant. The aggressive vines can reach the tops of tall trees. They rarely strangle limbs or young tree trunks, but have the potential to do so. They are more likely to crush fences and lattice. Wisteria really needs sturdy trellises and specialized pruning for confinement. Vines that grow from seed may take many years to bloom. The pinnately compound leaves turn pale yellow before falling in autumn.