by John Smelser

Conifers are cone-bearing plants and include such common plants as pines, sprucea, junipera and yews. Most are recognized by their needle-like foliage and may often be described as needled evergreens. Although most conifers retain their needles all year long and are indeed evergreen, some, such as bald cypress, dawn redwood, and larch are decideous and drop their needles in the fall.

Many common conifers are native to the cool, boreal (northern or mountain) forests. They do not, as a rule, do well in the hot, humid summers common to St. Louis. Following are some that have proven dependable and warrant planting. Both evergreen and deciduous conifers are included. 

Cedrus libani subsp. stenocoma
cedar of Lebanon

The cedar of Lebanon is famous for its historical and biblical associations; the oldest recorded specimen still in cultivation in England dates back to about 1638. The subspecies stenocoma is native to southwestern Turkey. It is hardier than the species and will grow well in zones 5 & 6. Juvenile plants are pyramidal with a strong and straight trunk. As they mature they become flat-topped and broadly spreading. A mature height of 40-60 feet and a spread of 30-50 feet dictate a site that gives this majestic tree plenty of room in which to grow and mature. This image is used to illustrate a mistake that all too many landscapers and homeowners make; planting potentially large conifers close to a building. Granted the trees look beautiful close to this art deco home, but if the trees were located halfway between the home and the street they could grow without disturbance for generations. In their present location they will eventually be pruned to accommodate windows, walks, and doorways; their beautiful form and character will be significantly altered or possibly destroyed. Careful attention to siting this tree will insure a beautiful, stately and long-lived specimen.

Cephalotaxus harringtonia
Japanese plum yew

Many gardeners are familiar with the value of shrub forms of the true yew, Taxus spp.; they grow well in shady areas and form a terrific dark green background for more colorful shade-loving plants. Far fewer gardeners are familiar with the Japanese plum yew, Cephalotaxus harringtonia. It provides the same advantages as the more widely used true yews. Concomitantly, it has one significant advantage over true yews; it is far more tolerant of moist soils. This does not mean it will grow in waterlogged sites. It means it can better adapt to areas that are moist, yet still drain well. For this reason, it is a terrific companion to hostas and ferns, plants that require more moisture than other shade-loving perennials. Japanese plum yew is very slow growing so you are well advised to buy the largest plant you can afford for more immediate effect in the garden.

Chamaecyparis pisifera 'Filifera Aurea'
Japanese falsecypress

Japanese falsecypress will begin life in your garden as a straggly, weepy, thinly foliaged, altogether pathetic looking plant. You might find yourself wondering briefly at times why you bothered to buy and plant it. Be patient. With each passing year it will develop more foliage density and better foliage color. As those years pass, and as fellow gardener comments grow more and more complimentary, you will thank yourself for engaging in this somewhat long range project. Your garden will contain a reasonably rare, broadly conical needled evergreen with foliage colored like the summer sun. Pictured is the cultivar ‘Filifera Aurea’, golden threadleaf Japanese falsecypress - a Plant of Merit. Avoid planting it close to columnar plants. Doing so will create a sense of visual “tension” in your garden. Locate it close to broadly spreading plants and you will be mightily pleased with your own sense of design. Excellent companion conifers include Blue Pacific shore juniper, Juniperus conferta ‘Blue Pacific’; dwarf globe blue spruce, Picea pungens ‘Glauca Globosa’; dwarf Eastern white pine, Pinus strobus NANA GROUP; and dwarf Scotch pine, Pinus sylvestris ‘Glauca Nana’. Complimentary broadleaf shrub companions might include Shaina Japanese maple, Acer palmatum ‘Shaina’; Varder Valley English boxwood, Buxus sempervirens ‘Vardar Valley’; Midwinter Fire dogwood, Cornus sanguinea ‘Midwinter Fire’; and Graham Thomas rose, Rosa ‘Ausmas’ GRAHAM THOMAS.

Juniperus horizontalis
creeping juniper

Creeping junipers are noted for their ability to provide a very low growing evergreen groundcover for hot, dry, full sun locations in the garden. They also look beautiful cascading over the edge of a large flat rock or a retaining wall. MBG lists several cultivars of creeping juniper in PlantFinder. Particularly attractive cultivars include:

Blue Chip’ – A cultivar with very good blue-green foliage that turns shades of plum and purple in winter.

Emerald Spreader’ – A cultivar with good green foliage that turns purple in winter.

Mother Lode’ – [Pictured] Iseli Nursery once discovered a large planting of creeping juniper that had been struck by lightning. The foliage had not only survived, it had turned a brilliant gold color that persisted through the years. This foliage was vegetatively propagated and named ‘Mother Lode.’ The foliage turns golden bronze in winter. This cultivar would look stunning planted at the foot of one of the weeping conifers featured in this article.

Plumosa’ – Commonly called Andorra juniper, this cultivar grows much higher than other creeping junipers [to 2 feet]. The foliage colors to a very attractive purple in winter. Individual plants assume a semi-rounded form in the garden. Planting it in groupings or “drifts” creates roller-coaster hummocks of color in your garden bed.

Juniperus virginiana
Eastern red cedar

Eastern red cedar, a Missouri native, is an exceptionally hardy broadly conical evergreen for hot, dry, sunny locations. It should be noted that Juniperus virginiana exudes a chemical from its root system that inhibits the development of competing vegetation on the ground under its crown. This does not bode well for the gardener who wishes to establish bulbs, perennials and annuals in its shade. We suggest giving it a location with room to spread and allowing the branches to touch the ground for best effect. The species is a viable evergreen tree for St. Louis gardens. Its cultivars, however, are equally desirable. Two exceptional choices are:

Canaertii’ – [Pictured] This cultivar has exceptionally bright green foliage. Its habit is pyramidal when young, with ascendant, irregularly sized branches, giving the plant an interesting asymmetric habit. In summer this cultivar develops beautiful robin’s egg blue berry-like cones that attract many birds to the garden. Like the species, ‘Canaertii’ eventually becomes a large imposing specimen, so give it plenty of room to spread, preferably in an expanse of lawn.

Grey Owl’ – This interesting cultivar has a broad spreading habit. Mature height is usually 3 feet, with a 6 foot spread. The foliage has a beautiful, soft silver grey color. This cultivar also produces blue berry-like cones that attract birds to a garden.

Picea abies

 The staff at the Kemper Center is confident that Norway spruce is one of the few tree-sized conifers that grow quite well in many St. Louis gardens. It is a beautiful tree with a pyramidal habit and irregularly sized ascendant branches. The branchlets, however, are pendulous, giving Norway spruce a very unique and attractive look. Cones are reddish-brown, contrasting nicely with the dark green needles. In addition to the species, several smaller cultivars of Norway spruce deserve serious consideration for inclusion in your garden:

Kellerman’s Blue Cameo’ – This is an excellent selection for those who want a small rounded needled evergreen in their garden border. Typical size at maturity is about 3 feet high with an equal spread. The needles have a somewhat blue coloration that is subtly beautiful.

Acrocona’ – An MBG Plant of Merit and a delightful compact conifer. It typically grows no taller or wider than 10 feet, making it an ideal candidate for smaller gardens. Because it succeeds most admirably in cooler summer climates you will want to locate it where it is protected from direct summer afternoon sunlight. Light shade from noon to four will benefit this plant tremendously. Some protection from prevailing summer winds would also be beneficial. One of the most pleasing aspects of this conifer is the “raspberry-red” cones that develop on the tips of the branches in spring. They develop even on the youngest of plants. The cones are responsible for the name of this plant; 'Acrocona’ means “with terminal cones on the ends of the branches.”

Pendula’ Weeping Norway spruce is a deservedly attention-getting compact conifer. Very dark green needles clothe an irregular form that will generally not grow upwards unless staked. The specimen at MBG was staked to a height of about 6 feet, and then allowed to cascade at will. As can be seen, it has developed into a striking specimen plant. For the best possible appearance, allow some of the branches to creep along the ground without interference from companion plants. Also consider planting it behind a large boulder and allowing the branches to creep over its top. As a specimen cascading over a retaining wall it is equally impressive.

Picea pungens
Colorado spruce

Generally, species trees of Picea pungens, Colorado blue spruce, do not perform well in the St. Louis area as large, full size trees – they struggle - and MBG does not recommend growing it as such. Given the right soil and location, however, Colorado spruce has performed well in certain areas so consult your local nurseryman. Some of the smaller, dwarf cultivars perform very well in St. Louis gardens. Excellent choices include:

Fat Albert’ – [Pictured] This cultivar of Colorado blue spruce keeps excellent blue foliage color throughout the growing season. Its form is truly pyramidal and its compact habit makes it perfectly suited to smaller gardens and garden beds. It is known for its strong, straight central leader. Like most conifers, it prefers well-drained soil, and in locales further west than St. Louis, where summer sun is intense, it prefers light shade from noon to four o’clock. PlantFinder notes that ‘Fat Albert’ will tolerate full sun in St. Louis. If you want your spruce to have healthy foliage from the ground up, avoid surrounding it with plants that grow more than 12 inches in height. Low-growing perennials and groundcovers are your best bet. Attractive companion groundcovers might include greater or lesser periwinkle, Vinca major or V. minor; foamflower, Tiarella spp.; ornamental sweet potato, Ipomoea batatas; English ivy, Hedera helix; plumbago, Ceratostigma plumbaginoides; or lily turf, Liriope muscari.

Glauca Globosa’ – This cultivar has a somewhat flattened top, maturing at 3-5 feet in height, with a 4-6 foot spread. It is sometimes sold as a standard on trunks 2-3 feet in height. Despite the occasional sales pitch, these are not recommended for containers.

Montgomery’ – Another cultivar that holds its blue foliage color throughout the year. This cultivar stays very small compared to the species, sometimes maturing at about 3 feet with a similar spread. This makes it a wonderful choice for those desiring a small, rounded spot of blue in their garden.

Pinus bungeana
Lacebark pine

Lacebark pine is a needle evergreen tree that is all too seldom available in the trade, and all too infrequently planted in gardens. If your garden has room to contain a potentially large conifer, however, this tree should be at the top of your short list. When available it is often found as a small multi-trunked specimen, but single-trunk specimens can be found. In either form it deserves a prominent garden location for one simple reason: the bark. The bark is not very showy on young plants, but patience is rewarded. As the tree develops the bark begins to peel and reveals an underlying patchwork of white, olive, light purple and silver, eventually becoming milky white at maturity. Some of the oldest specimens of this tree are reported to have pure white bark. Imagine this bark with a backdrop or underplantings of dark green foliage and you might better understand the allure of this beautiful conifer.

Pinus densiflora ‘Umbraculifera’
Tanyosho pine

The Tanyosho pine is an absolutely stunning needled evergreen. Virtually all aspects of its appearance and habit are attractive. It develops into a multi-trunked specimen at an early age, giving a single plant the look of a small grove. The bark color of orange-cinnamon with streaks of grey stands out beautifully in the winter landscape. The broadly rounded crown with a somewhat flat top offers an impression of “shelter” in the garden. The needles are bright and cheerfully green in winter as well as the growing season. Several magnificent specimens can be seen in ‘Seiwa-en’, the Japanese stroll garden within the Missouri Botanical Garden. If your garden is too small to accommodate this plant it can surely benefit from an available dwarf cultivar that seldom exceeds 6 feet in height and spread. This is one of those plants that should be seriously considered when looking for a “focal point” specimen for your garden.

Pinus strobus
Eastern white pine

All too often the species Pinus strobus, Eastern white pine, does not perform well in the St. Louis area as large, full size trees and MBG does not recommend growing it as such. Given the right soil and location, however, it can perform well in the St. Louis area so consult your local nurseryman. One of the nicest attributes of eastern white pines is their soft needles. Unlike the stiff, sharp needles of other pines these are actually a pleasure to touch. Because they occur in bundles of five, as opposed to the two needle bundles of other pines, this pine has a lushly dense appearance. Some of the compact and dwarf cultivars perform very well in St. Louis gardens. Excellent choices include:

NANA GROUP. This group includes several cultivars that have semi-dwarf to dwarf forms. Most do not grow much taller than 2 feet, but spread more than that. These are very desirable cultivars for use toward the front of the garden borders, where their form and soft, blue-green foliage can be appreciated up close.

Pendula’ – Weeping eastern white pine is a desirable cultivar for stand-alone specimen status in the garden. This semi-dwarf cultivar generally does not exceed 6-15 feet in height. Its weeping habit allows it to have a somewhat larger spread, with branches that often touch the ground. The result is a spectacular mound of soft-to-the-touch blue-green needles. Try to avoid the temptation to cram this plant into a border filled with other plants. Consider planting it in a large border or a lawn area with plenty of room to grow and spread. It would also look terrific at the top of a retaining wall, with branches cascading over the edge, serving as an elegant counterpoint to the hard surface of the wall.

Sea Urchin’ – This MBG Plant of Merit is a very desirable cultivar of eastern white pine. Its dwarf size makes it a good candidate for small gardens. The blue-green needles are an attractive compliment to almost any companion plant. Plant it close to walkways, entries, decks and patios so it can be viewed easily and in detail.

Japanese yew

Japanese yew truly qualifies as a “groundcover” conifer. It is the rare yew that can be successfully used at the front of a garden border. It is almost unequalled in beauty as a plant cascading over rocks or a retaining wall. Lustrous dark green foliage clothes a form that rarely exceeds 2.5 feet in height, but can spread to about 9 feet at maturity. The image shows this yew growing in a container in a zone 7A garden. But St. Louis gardeners should not waste it in containers. The colder, zone 6 nature of St. Louis gardens dictates planting in the ground. This is a yew that should not be pruned; its natural beauty would simply be ruined by shaping it unnaturally. It would look wonderful planted in front of 3-foot-plus perennials or at the base of rhododendrons and azaleas.

Taxus x media

This category of yews was achieved by crossing English yew with Japanese yew. The resulting cross, and further hybridization, has resulted in some remarkably attractive and garden worthy needled evergreens. Yews are familiar to gardeners who desire an evergreen plant for a shady location. St. Louis gardeners are fortunate in that they can also locate yews in full sun. Two exceptional cultivars of Taxus x media are:

Citation’ - This form offers gardeners an attractive vertical statement that looks great flanking entryways, porches, and patios. It also makes a much more manageable hedge plant than, say, ‘Green Giant’ arborvitae. This is true because [1] its height stays, at most, around 10 feet and can therefore be easily kept to a shorter height [2] yews are more amenable to pruning than arborvitae and [3] yews are less prone to insect infestations than arborvitae. Yews are venerable plants, living sometimes for hundreds of years. That is why so many of the finest old English gardens use yews as hedging plants. One caveat: locate yews on the south or east sides of your home in St. Louis to avoid foliage burn from winter winds.

Densiformis’ – [Pictured] This is an outstanding spreading form of yew. It is equally beautiful in groupings or as a stand-alone specimen. It serves as a great dark green backdrop for shade or sun loving perennials and annuals. It is also a wonderful companion planting for rhododendrons and azaleas. Please don’t shear it; its natural form is simply too pretty to be butchered into a ball or a box.

Thuja ‘Green Giant’

‘Green Giant’ arborvitae as an MBG Plant of Merit came as a genuine shock to this writer. After all, this plant, or one of its variations, has for decades been the “cute little cone of green” that everyone planted at the corners of their home. The trouble was, and still is, that the cute little cone eventually grew large enough to literally engulf the house corner and part of the roof, as well as blocking the view from any window close to that house corner. But reading the PlantFinder article on ‘Green Giant’ made it clear this plant is being recommended as a stand-alone specimen… and as the large tree it will become. Knowing that gives this plant a whole new perspective. Arborvitae is a majestic, long-lived, and very hardy garden tree. Its foliage is soft to the touch and attractively green year-round. Its trunk and branches have a look of venerable strength. ‘Green Giant’ is a hybrid with a strong straight trunk and a dense, narrow, pyramidal habit. It will make an impressive vertical statement in any garden large enough to accommodate it. Just, please, don’t plant it up against the corner of your home. By the way, also try to avoid using it as a hedge plant for a couple of reasons. First, bagworms are more likely to occur on heavily pruned, and therefore stressed, plants and that means you will have to periodically spray to control infestations. Second, the continual trimming required to keep a hedge looking neat and uniform is hard work, whether you or your “yard man” has to do it. Remember, “hedging” this plant means you are trying to keep a 40-60 foot tree in the 6-12 foot height range. That involves a lot of labor by anyone’s standard. By all means use this majestic plant, but give it the stand-alone status it deserves.

Three Non-Evergreen Coniferous Trees

The vast majority of conifers have evergreen foliage. Four genera of coniferous plants, however, have deciduous foliage that falls from the plant for the winter months. Of these, three genera will perform very satisfactorily in St. Louis gardens and are worthy of mention. These three deciduous conifers are largely free of insect and disease problems due to their extraordinarily long lineage in the natural world. They are certainly worthy of planting in St. Louis gardens. Care, however, should be given to siting them where they will have plenty of room to grow and spread.

Ginkgo biloba
maidenhair tree

The ginkgo, or maidenhair tree, is so named because its leaves resemble the leaflets of maidenhair fern. Ginkgo trees are slow growing, pyramidal as a juvenile, with a broadly spreading crown at maturity. The leaves turn a beautiful butter yellow in fall and drop almost all at once, creating a gold carpet beneath the tree in late fall. Because this tree does not transplant well when field grown, most horticulturists recommend purchasing container grown trees.

Metasequoia glyptostroboides
dawn redwood

Dawn redwoods were long thought to be an extinct tree. In the 1940’s, however, living specimens were found growing in the wild in a Chinese forest. Propagation of this rare tree, and its availability to gardeners, is attributable to the Missouri Botanical Garden. This deciduous conifer makes a dramatic, conical, vertical statement in gardens. Its foliage is wonderfully soft to the touch and turns attractive shades of bronze-red before defoliating in the fall.

Taxodium distichum
bald cypress

Bald cypress is perhaps most famous for growing in the swamps of southern Louisiana. But it is an admirably adaptable tree and grows beautifully in St. Louis gardens. Its soft, feathery foliage contrasts nicely with its straight-as-an-arrow central leader and strong, buttressed trunks. The foliage turns an attractive reddish bronze in the fall.