Juniperus
There are approximately go species of junipers found in thenorthern hemisphere of the world. Over 170species and varieties are being offered byAmerican nurserymen today. These are allevergreens, have needlelike or scalelike leavesand the fruits are small blue berries, usually lessthan in. in dia. The foliage varies greatly,young leaves being more sharp and pointedthan mature leaves, and sometimes this varieson the same plant. The sexes are separate so itis only the pistillate or female trees that bearthe small berries and on some species thesetake 2 and even 3 years to mature.
Junipers range in size from prostrate groundcovers to trees. They are among our mostserviceable landscape plants for they are sodiversified there are always a few for any land-scape planting. They are valued because theygrow well in hot, dry, sunny situations, especi-ally under urban growing conditions. Most canbe pruned easily and they will respond well;some can be sheared in hedge form. Theyapparently do well on either acid or alkalinesoil, but are supposed to do best if the soil isnot too acid.
Unfortunately, they are susceptible to severalpests. The cedar-apple rust is one disease inwhich part of the life cycle is spent on thejunipers and part on certain rosaceous plantslike apples, cotoneasters and hawthorns.Remove one of the plants and there is nodisease, but if both are grown, the peculiarhornlike, fleshy growths appear on certain ofthe junipers, especially during wet weather.
PropagationSeeds of many take 2 years to germinate andso should be stratified at room temperature for3-5 months, then at 40¬∞ F. for 3 months to breakthis dormancy. Hardwood cuttings of manykinds can be rooted; those that are difficult aregrafted on J. virginiana or J. chinensis ‘GlaucaHetzi’ understock, the latter rooting easily from cuttings.
Insect Pests
Spindle-shaped bags enclosing the bagwormwhich may defoliate the ornamental varietiesare very conspicuous in the warmer areas. Thewinter eggs do not survive freezing. Hand-picking is practical on a few plants and insecti-cides # 5, # 9, and #42 are recommended forspraying. White juniper scale on the needles ofmany junipers is controlled by a dormant spraywith insecticide #44 or when the young areactive in early summer, with insecticide #15.Spruce mite often infests Juniper and requirescareful control. Juniper web wormsfeed on leaves enclosed in a noticeable web inearly summer and again in the fall. Insecticides# 5, # 37 and # 42 give control.
Diseases
Twig blight, caused by a fungus attackingnew growth, is very destructive in nurseries. Thedead leaves are covered with tiny black spots.Spraying with fungicides # K or # G isrecommended.
Cedar-apple rust, cedar-hawthorn rust andcedar-quince rust, all spend a part of theirdevelopment on Juniper where they producereddish-brown galls or “cedar apples” orswellings on the twigs. The cedar-apple rustdevelops on Juniper the and year followinginfection but others are perennial. Damage toJuniper is usually less important than to thealternate host. Spraying in midsummer withfungicides #D or # F is recommended. .
chinensis 60′ Zone 4 Chinese Juniper
There are many varieties and cultivars of thisexcellent species ranging in size from groundcovers to trees. It would seem advisable to buynamed varieties or cultivars rather than seedlingswhich vary considerably. The species is nativeto China and Japan, has foliage a lighter greenthan does the native Red-cedar virginiana)and the fruits are larger, up to in. in dia. Thisis a good ornamental tree but it is surpassed invalue by more recently introduced varieties andcultivars which will give more specific ornamen-tal values in the landscape planting.
‘Ames’, a pyramidal shrub with steel-bluefoliage‚Äîa ea-year-old specimen is 7 ft. tall;`ArmstrongiP, a sport or seedling of J. chinensis`Pfitzeriana’, this is a slow-growing shrub of thePfitzer Juniper type reaching a height of 4 ft.and with a softer blue-green foliage; `Blaauw’,received from Japan with a blue featheryfoliage; ‘Columnarie, this is called the BlueColumnar Chinese Juniper and is narrowly columnar in habit, with silvery-green foliage.All the leaves are juvenile, that is, they aresharply pointed; `Glauca Hetzi’, a very denseshrub, 55 ft. tall and about as wide; with uprightbranches. It definitely does not have the habitof a Pfitzer Juniper but it does have light bluishfoliage; `Iowa’, a pyramidal tree supposedlyresistant to the cedar-apple rust disease; hasirregular upright growth to about so ft. tall,bluish foliage and bears fruit; `Keteleerr, this isa broadly pyramidal tree with a stiff trunk andloose foliage, selected about ‘soy. It is still oneof the best varieties of J. chinensis. At one timeit was listed as a variety of J. virginiana, butthere is no question about it being a ChineseJuniper for its large light blue fruits are almost 1 in. in dia. The foliage is green; the cultivar’Mountbatten’ has foliage of a grayer color andit is more juvenile; ‘Mac’, a densely columnarform mostly with acicular leaves and usuallywith staminate flowers. This seems to be one ofthe excellent columnar forms of J. chinensis andmight well be used more than it is; `Moraine’, asport of the Pfitzer Juniper, introduced in 1949especially for its blue-green foliage and compacthabit. It is similar in some respects to `Nick’sCon-space; `Mountbatten’, introduced in 1948,this is an excellent narrowly columnar tree anda seedling of J. chinensis. The foliage is agrayish-grcen color because the majority of theleaves are the grayish juvenile or acicular type,but the dense compact habit gives one the impression that the plant has been sheared. Thisis one of the best of the fruiting Chinese Junipercultivars; `Nick’s Compact’, very definitely asport or a seedling of the Pfitzer Juniper, this isone of the best of the compact junipers. A to-year-old plant is 6 ft. across and only 12 in.high. It is flat on top and is an excellent compactform without the vigorous growth of thePfitzer Juniper; `Obelisk’, this is a fruitingpyramidal tree with steel-blue foliage color. Itresembles J. chinensis rmo but is claimed to bemore attractive because of truncated branchingand its excellent blue color. It keeps this com-pact habit without trimming and grows com-paratively slowly; `Parsonii’, no juniper has been carried under more names than this excel-lent little plant from Korea. Probably firstintroduced to America by the old ParsonsNurseries of Flushing, Long Island, N.Y. It hashad at least 6 other names and may be carriednow under an assortment of them. The plantforms at first a wide, quite low and flat spreadwhich for some years may not exceed 12 to 15 in.in height. Ultimately, it builds itself up into adomed, rather rounded mound to some to ft.wide and about 04-3 ft. high in the center. Thebranches are stiff, held rigidly horizontal,slightly above the ground making it splendid asa single specimen with lovely dignified gray-green foliage; `Pfitzeriana’, this is a cultivar,originating as a single plant in the SpaethNurseries of Berlin, Germany, in 1899. One ofthe best of all the shrubby junipers, its goodqualities are well known. However, in theireffort to see compact-growing forms or cultivarsof this particular juniper, many selections ofsports and seedlings have been made, especially in recent years. Now, there are some excellentforms being grown and sold including ‘Arm-strongir, ‘Aurea’, and ‘Nick’s Compact’,`Pfitzeriana Aurea’, this is a sport of J. chinensis’Pfitzeriana’ and is not to be confused with thebotanical variety J. chinensis ‘Aurea’. In theheavy clay soils of Ill , the young foliage is abeautiful golden yellow but in certain soils ofdifferent texture (notably in Calif. and R.I.) thefoliage color is not so pronounced; `PfitzerianaGlauca”‚Äîthis differs chiefly from the PfitzerJuniper in that the foliage is blue-gray and notgreen. It was patented (Plant Patent #4.l;’Pyramidalis’‚Äîa narrow, pyramidal, compactform with upright branches and crowded upright branchlets. The leaves are usually acicular andternate, under in. long and glaucous. It shouldbe noted that the plant commonly known inthe trade as J. excelsa stricra is actually thisvariety of the Chinese Juniper. J. excelsa is atender Juniper hardy only in Zone 7; `Richeson’‚Äîa sport of the Pfitzer Juniper, this differsfrom the parent plant in being dwarf, and it alsohas an excellent gray-blue color; plants 08-3 ft.high are 4-5 ft. across. A 14-year-old plant isonly so in. tall and 4 ft. across; sargentii‚Äîi ft.,Zone 4, Sargent Juniper, forming a mat 8-to ft.across, this rugged juniper makes an especiallyfine ground cover. It is gray-green in color andnative to seashore areas of northern Japan; `SanJose’‚Äîthis lies flat on the ground, displays amixture of juvenile and adult foliage and hasbeen extremely popular in Calif. The foliagecolor is a good sage green and it has proveda most popular prostrate juniper for manyyears; sylvestris‚Äîthis is apparently widelygrown in the South. It is a broadly pyramidal plant with gray-green foliage. A plant 20 ft. tallmay be about 8‚Äîto ft. in dia.; torulosa‚Äîanarrow upright juniper with bright green tuftedfoliage proving extremely popular in Calif., butapparently not hardy in the northern U.S. Itwill grow over 15 ft. tall and has a unique andpicturesque habit which should not be modifiedby pruning.
chinensis procumbens 2′ Zone 5 Japanese Garden Juniper
This is a low, creeping. though sometimesmounded plant from Japan, making one of thebest of ground covers. It is not nearly as vigor-ous in growth as is J. horizontalis, but thebluish-green needles and dense habit make it amost desirable plant. Plants have been observed20 S. wide and 3 ft. high in the center. Thevariety ‘Nana’ is one of the best of the smallerjunipers, rounded in habit. producing branchesin a shelving effect, one on top of the other.Actually, it is a small counterpart of the speciesand with its blue-green foliage and small, dense,rounded habit it can be outstanding. Apparentlya restriction of root growth aids in keeping thisform from eventually reverting to the morevigorous type of growth of the species.communis 2′-36′ Zone 2 Common Joni,A widely-distributed shrubby juniper found inEurope, Asia and North America in manydifferent sizes and shapes. It frequently turns abrownish color during the winter in the northernU.S. Be-cause the species varies so widely inhabit from a ground cover to a tree 36 ft. tall, itis best to grow only the botanical varieties andcultivars, propagating these asexually to main-tain the desired habit. One of the ways ofidentifying this species is that winter buds areusually present in the axils of the leaves. Thefruits are an essential ingredient of gin and theyalso have been roasted by the earlier settlers andused as a substitute for coffee. The varieties areas follows: `Compressa’‚Äîthis is a dwarf fastigi-ate form originating about 1855, making anexcellent focal point in the small garden orrockery, seldom growing more than 2 ft. tall;’Depressa’‚Äîthe Prostrate Juniper is one of themost commonly seen in eastern North America,forming large patches in open fields, especiallywhere the soil is poor. It rarely grows over 4 ft.tall, having many stems ascending from thebase; ‘Gold Beach’‚Äîa new flat form with younggrowing tips colored yellow early in the spring.Eventually this will be a very popular variety;’Oblongo-pendula’‚Äîthis is a broadly columnarshrub or small tree with pendulous branchletssometimes as ‘much as 2 ft. long. It is moredense and makes a better specimen than eitherJ. formosana or J. rigida, and can be consideredone of the most graceful of all junipers; `Stricta’‚Äî.the Irish Juniper. This came to America from Ireland about 1836, and is more compact thanthe Swedish Juniper, with dark green foliage.Formerly known as J. communis hibernica, thisis slightly more hardy than J. cormnunis’Sued.’; `Suecica’‚Äîa native of Scandinavia,this upright, almost columnar shrub is charac-terized by the nodding tips of the branches andbluish-green foliage, making it a very gracefulspecimen where it is hardy. It is commonlyknown as the Swedish Juniper, but in Boston,Mass., the foliage is susceptible to winterburning.
conferta 1′ Zone 5 Shore Juniper
A low ground cover, trailing flat along theground, this might be used in America con-siderably more than it has been. It is especiallyadapted to planting in sandy soils at the seashoreand in full sun‚Äînative to the seacoast of Japan.darnrica ‘Expansa’ = J. chinensis ‚Ä¢Parsonirdeppmma 6o Zone 7 Alligator JuniperA native of the dry southwestern U.S., this isone of the handsomest of American junipers. Ithas checkered bark and silvery-white foliage butit is hardy only in the southern U.S. A variety,ericoides, has been named for its unusuallyglaucous foliage.
excelsa `Strieta’ as’ Zone 7 Spiny Greek Juniper
This is not hardy in the central and northernUnited States. The plant widely grown underthis name is actually J. chinensis ‘Pyramidalis’.The true Spiny Greek Juniper is a denselycompact, pyramidal, slow-growing tree, withglaucous juvenile foliage, hardy only in Zone 7.The species, J. excelsa from Greece grows intoa narrow pyramidal tree 6o ft. tall, hardy inZone 7.
horizontalis TV‚Äîi8″ Zone 2 Creeping Juniper
The Creeping Juniper is a popular native to thenortheastern United States, and it has manycultivars. The commercial nurseryman mightdo well to offer cultivars rather than the speciesor collected plants because such plants varygreatly. Some grow with long, narrow streamersof stems while others are more compact andcover the ground better. Still others retain theirgreen foliage color throughout the winter whilesome turn an excellent purplish color in the falland winter. The slowest growing form, J.horizontalis `Glomeratte, may grow as much asft. tall and is not very spreading. Like alljunipers, this species and its varieties withstandhot, dry situations, growing well under cityconditions and in slightly alkaline soils.
The varieties are as follows: ‘Bar Harbor’‚Äîthis is a sturdy selection of the native J. horizon-tails growing in the vicinity of Bar Harbor, Me.It is a creeper, somewhat more compact thanthe species, but difficult to identify from other good J. horizontalis forms; `Douglasir ‚ÄîtheWaukegan Juniper is an excellent trailingvariety with steel-blue foliage which turnspurple in the fall. Introduced before 1855 bythe Douglas Nurseries of Waukegan, Ill., whereit grows about the bluffs bordering LakeMich.; ‘Emerson’‚Äîthis low shrub was foundin the Black Hills of S.Dak., first called ‘BlackHills Creeper’ 40 or Sc years ago. It has beenrenamed ‘Emerson’ in honor of one of the menwho found it. The plant is very prostrate, bluein color and holds this blue color throughoutthe winter. Slow in growth and able to grow indry soils, it seldom exceeds 1 ft. in height;’Plumosa’‚Äîthis is the Andorra Juniper, dis-covered and named by the Andorra Nurseriesof Chestnut Hill, Phila., Pa. in 1916. It is a flat-topped variety with a low compact habit ofgrowth, reaching a height of approximately t8in. with the branches spreading uniformly fromthe center. This is the variety which has gray-green foliage during spring and summer, turningan excellent purplish green in the fall; `Wiltonir‚ÄîMr. Jacob C. van Heiningen of Wilton, Conn.selected this on the Island of Vinal Haven, Me.in t914. It is this same variety which has beenoffered under the much more imaginative nameof J. horizontalis ‘Blue Rug’. The foliage is of anoutstanding blue color which it retains allwinter. The plant grows flat on the ground.lu.yana 50′ Zone 9 West Indies JuniperNative in the West Indies, this is a substitutefor J. virginiana (and is similar to it) in thewarmer parts of the country where the northernspecies will not grow. It has been considered oneof the most beautiful of all the junipers.
osteosperma (atahensts) s 8′ Zone 7 Utah Juniper
A bushy evergreen tree, native from Wyo. toCalif., and of no particular ornamental valueoutside its native habitat.
recurva Coxii 80′ Zone 7 Cox Juniper
With a single erect trunk and graceful pendulousbranches, this makes an excellent ornamentaland apparently it is being used now to someextent in southern Calif. The foliage is a richdark geese. Native to Upper Burma.
rigida 3o’ Zone 5 Needle Juniper
A graceful, pyramidal tree with pendulousbranchlets, native to Japan and Korea. It is nota good plant to shear, nor is it sufficiently densefor a windbreak, its sole value being its gracefulappearance as a specimen. It is similar to J.fortnosana and has been perfectly hardy inZone 5 sin. 1885.
sabina 15′ Zone 4 Savin Juniper
A shrub native to Europe, either low andspreading or upright in habit, growing well inlimestone soils as do most junipers. The foliageis not especially beautiful when the plant reaches maturity; hence it is one which shouldbe used while it is young. The variety `Arcadia’is t of 3 cultivars individually selected frommany thousands of J. sabina seedlings importedby the D. Hill Nursery Company, Dundee, Ill.,from a government forestry station nearLeningrad, Russia, in 1933. All 3 are provingresistant to the Juniper blight which is seriouslytroubling most plants of J. sabina in the Mid-west. This cultivar is a gray-green color. Plants12-14 in. high are ft. across. All in all, at firstglance, this resembles a very low, flat-topped,green Pfitzer Juniper. The varieties are:’Broadmoor ‚Äî1 of 3 cultivars selected in 1933from seedlings received at the D. Hill NurseryCompany, Dundee, Ill., from Russia. Mr. JohnD. Hill reports that its “growth habit is moregenuinely recumbent than prostrate,” and hencethat it appears to be mounded. One specimen,now 12 ft. across, is 5o in. high at the centerwhile half way out to the tips of the branchesthe height is only 8 in. The foliage color is asoft gray-green and the plant is staminate;`Tamariscifolia’‚Äîa loot, spreading juniper withlight green foliage and procumbent branchesascending at the tips. It makes an excellentground cover with very dense foliage and hasbeen popular in landscape planting many years,called the Tamarix Savin Juniper; ‘Von Ehren’‚Äîthis plant grows vigorously, a 12-year-oldspecimen being 3 ft. tall and 8 ft. across. Anotherplant near Dundee, Ill., is reported to be 15 ft.tall and 45 ft. across. It is similar to J. sabina,but it is much more vigorous and somewhatdarker in color and, what is even more import-ant, it is reported to be resistant to the juniperblight.
scopulorum 36′ Zone 5 Western Red-cedar
Often known as the Rocky Mountain Juniperbecause this is its native habitat, it is a stnalltree widely distributed over the Rocky Moun-tain Area of North America from BritishColumbia to Calif. It survives in the hot, drysummers of that area but does not grow nearlyas well in the eastern U.S. as the Eastern Recl-cedar, J. virginiana. Over 40 forms have beenselected for their blue foliage color and grownby nurserymen during the past few years. Someof the more popular varieties are: `ChandlerBlue’, `Hill’s Silver’, ‘Moonlight’, Pathfinder’,'Silver Beauty’ and ‘Sutherland’, but there arcmany others probably just as good if used neartheir native habitats.
squamala 3′ Zone 4 Singleseed Juniper
A low shrub with bluish-green needles, compacthabit, small black fruits, native to China. Betterknown is its more upright variety `Meyerr, theneedles of which are whitish on the back givingthe plant a light blue appearance. However, thisoften does not mature gracefully in the eastern U.S. The branches are upright but usually itsgrowth is such that it is not a dense pyramid offoliage but often it has an irregular shape withthe central leader growing off at an angle. It isa good ornamental only while the foliage is keptin a vigorous growing condition. Poorly grownplants quickly become unsightly.
virginiana 90′ Zone 2 Eastern Red-cedar
The Eastern Red-cedar is the hardiest and mostpopular of the tree junipers, native over nearlythree-fourths of the U.S., and commonlyplanted everywhere. There are many excellentcultivars being offered but the species is still agood plant even though grown from seed, whichof course results in considerable variation. Likeother junipers, it is dioecious with staminate andpistillate flowers on separate plants. It growsrather slowly but in good soils lives a hundredyears and more. Most are narrow to widelypyramidal in habit. A very few of the bettervarieties which should be propagated asexuallyare: `Burkii’‚Äîthis cultivar is very popularbecause of its gray foliage and purplish wintercolor. Since it is a cultivar and is propagatedasexually, its color is always uniform and henceit is considered better than some plants of J.virginiana glauca; `Canaertir ‚Äîoriginating inBelgium before 1868, this has long been popularbecause of its compact pyramidal habit, its darkgreen foliage which it maintains well throughoutthe winter and its profuse, bluish fruits whichare always an ornamental asset; creba‚Äîthis isthe narrow, pyramidal, sometimes columnarform native in the northern part of the U.S. andit is to this variety that most garden forms areclosely related. The species or typical -southern form” is usually much broader in habit withpendant branches; `Elegantissima’‚Äîthe GoldtipRed-cedar has been popular in the past becauseits branchlets are tipped with golden yellow. Itis a pyramidal tree, usually not over 20 ft. tallat maturity, and turns a good bronze color inthe fall; Tilifera’‚Äîis a broadly pyramidal treewith very slender, much-divided branchlets andgray-gems foliage; glauca‚Äîone of the bestcolored forms of this species, the Silver Red-cedar is a narrow columnar tree about 15-20ft. tall and has been recognized as a botanicalvariety since about 1850. The silvery-blue colorof the foliage is, of course, brightest in thespring, gradually turning a silvery green in thesummer; `Globosa’‚Äîa plant of this in theArnold Arboretum is not over 15 ft. high, yetit is 5o years old, an excellent rounded anddensely branched specimen; `KosterP‚Äîorigin-aced about 188o in the Koster Nursery ofBoskoop, Holland, makes an excellent 2-ft. highplant. A number of these growing in a groupsince 1916 have formed a mass of green foliageof uniform height. Actually, this cultivar stayslower in height than either J. virginiana ‘Tel-part ita’ (4 ft.) or J. virginiana ‘Reptans’ (3-7 11.);’Pendula’‚Äîthe Weeping Red-cedar has spread-ing branches and pendulous branchlets. A well-grown specimen does have merit, although it ismore open in habit than most of the columnarforms. It has been known since 1855; `SchottiP–comparatively small, this dense, green,narrowly pyramidal tree is not planted so muchnow as formerly, possibly because its foliagemay be yellow-green at certain times of theyear; `Skyrocker‚Äîupright, narrow; ‘Tripartita’ ‚Äîthe Fountain Red-cedar is dwarf and spread-ing, with several branches coming from theground, and is seldom over 4 ft. tall. Althoughmost irregular in habit, in general it remindsone of a vase-shaped TaX14‚Ä¢ cuspidate
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