Botany: The Science of Plant Life

by Norman Taylor

SHRUBS

While trees make the major feature of any garden, shrubs are chiefly used to fill in between them, or in small gardens the only woody plants that can be used are often shrubs. Within the last two or three years the Government has prohibited the importation of plants from abroad, upon the ground that various insect pests and fungous diseases were likely to be carried into the country upon such plants. For this reason American gardeners will have to propagate their own plants and we shall have to use more native plants than European and Asiatic species, which made up the bulk of our gardening material in the past.

There are excellent reasons for using native shrubs upon quite other grounds than the difficulty or danger of importing foreign ones. Native plants fit into the natural landscape better than introduced sorts, and very often the garden enthusiast can go out into the country and dig out small specimens instead of buying them.

In the list of native American shrubs given below, there are directions of where to use them, their heights, their flower color and other information about them that will help the amateur gardener to select his shrubs for definite effects. All of the shrubs listed can be gown in most parts of the country, and from the list nearly every wish of the garden planner may be gratified. This list is a practical one and has been used by landscape architects and others. It was written by the author for “The Garden Magazine” whose publishers, Doubleday, Page & Company, have kindly allowed its use here.

It will be noted that under each month group the names are arranged in botanical sequence so that allied plants are brought together. All the ninety-four species are offered for sale in American nurseries. Those in the column “Remarks and Notes” as well as about twenty others not included, must be collected in the wild.

A word now as to cultivation and care. Most of the shrubs, except those so noted, can either be planted in the spring or fall, as this is a matter that should be determined by the planter’s convenience. In digging the holes make them twice as wide and deep as the size of the roots apparently demand. Note carefully the column “Preferred Habitat,” so that the shrubs may find congenial surroundings. Pack the soil well around the roots, water thoroughly, and frequently if the weather is dry and windy. The first winter or two a heavy mulch of leaves, or leaves and manure mixed, to be dug in the following spring, will well repay the expense and trouble.

It will be noted that some of the shrubs are marked with an asterisk (*). These all belong to the heath family and require special treatment. A soil composed of rotten sods and leafmold, about half and half, is most essential for the successful cultivation of these plants. They require peculiar acid soil conditions well approximated by the above mixture, and a mulch, preferably of red-oak leaves, or the leaves of the mountain laurel if available. Never disturb the roots of these plants by digging in the mulch, which is better left on indefinitely. Soils with much lime in them must also be avoided when growing these heath-family plants.

It is often somewhat difficult in arranging a shrubbery planting to group the plants according to the color of their flowers. For the greater ease in using the larger table, and so that one can arrive at the relative frequency of the various colors desirable for use in the scheme, the following table is appended. The numbers refer, of course, to those in the table below. The figures given in parentheses are the total of plants in each division.

By color of flowers. Yellow-green (10): 1, 8, 9, 10, 30, 31, 36, 44, 49, 86. Brown-green (10): 2, 3, 4, 11, 12, 13, 14, 15, 27, 39. Yellow (5): 5, 25, 41, 84, 92. Pink-purple (4): 7, 74, 75, 83. White (35): 6, 17, 18, 19, 20, 21, 22, 24, 28, 29, 32, 40, 42, 43, 45, 46, 47, 51, 55, 57, 58, 59, 69, 70, 71, 72, 76, 78, 79, 80, 81, 82, 88, 89, 90. Green-white (11): 16, 23, 33, 50, 52, 63, 64, 65, 66, 87, 94. Pinkish-white (10): 26, 37, 38, 54, 56, 61, 67, 73, 77, 93. Pink (5): 34, 60, 62, 85, 91. Lilac (1): 35. Violet-purple (2): 48, 68. Orange-red (1): 53.

It often happens, too, that we have some definite spot, such as a small stream or swamp, a dry hill-side, or a shaded wood, that we wish to beautify. Therefore:

By preferred habitat of shrubs. Moist places (19): 1, 2, 4, 9, 15, 17, 30, 36, 42, 50, 75, 78, 82, 83, 84, 85, 87, 88, 89. Indifferent (32): 3, 5, 6, 7, 12, 14, 24, 29, 32, 35, 37, 38, 41, 43, 45, 47, 48, 51, 52, 59, 60, 61, 62, 68, 70, 71, 72, 79, 80, 81, 90, 91. Shaded woods (13): 8, 16, 23, 25, 26, 27, 31, 63, 65, 67, 69, 74, 92. Dry places (19): 10, 13, 18, 20, 21, 22, 34, 39, 46, 49, 53, 54, 56, 58, 64, 77, 86, 93, 94. Swamps (6): 11, 40, 55, 66, 73, 76. Thickets (1): 19. Cool woods (4): 28, 33, 44, 57.

In planning a screen for an unsightly fence or building, or to cover up some small landscape importunity, it is often essential to know, en masse, the heights of shrubs for such purposes. The following table gives the dimensions of the shrubs, normal individuals averaging about midway of the extreme heights given.

By height of shrubs. One to four feet (13): 2, 6, 21, 27, 34, 56, 62, 75, 77, 83, 84, 91, 93. Two to five (24): 10, 11, 13, 16, 22, 25, 31, 36, 37, 42, 44, 53, 57, 60, 61, 65, 67, 69, 73, 81, 82, 85, 90, 94. Three to nine (29): 3, 4, 8, 12, 14, 15, 17, 20, 26, 28, 32, 33, 35, 38, 39, 41, 43, 45, 48, 54, 58, 59, 70, 72, 74, 78, 80, 86, 88. Six to fifteen (21): 1, 5, 7, 18, 19, 29, 40, 46, 47, 49, 50, 52, 55, 64, 68, 71, 76, 79, 87, 89, 92. Ten to eighteen (7): 9, 23, 24, 30, 51, 63, 66.

PLANTING TABLE FOR OUR NATIVE SHRUBS[3]

	Common and Latin Names	Height (feet)	Color of Flowers	Preferred Habitat	Remarks and Notes
Flowering in MARCH-APRIL
1.	Pussy willow (Salix discolor)	7-12	Yellow-green	Moist places	Flowers before the leaves come out. S. cordata, a larger bush, with broad leaves is worth cultivating. Not in the catalogues.
2.	Dwarf willow (Salix tristis)	1-4	Brown-green	Moist places	Useful in masses. Can be made to grow in all sorts of places. One of the very earliest flowering shrubs.
3.	Hazelnut (Corylus americana)	3-6	Brownish-green	Indifferent[4]	Nuts edible much gathered by the squirrels, The catkins out before the leaves. European hazelnut is a better plant.
4.	Alder (Alnus rugosa)	5-9	Brownish-green	Moist places	Will grow in other situations. The fruits, not very strong, will stay on all winter. Useful in masses along brooks.
5.	Spice bush (Benzoin odoriferum)	6-15	Yellow	Indifferent	Flowers much before the leaves, very fragrant, Near N. Y. usually not over 10 feet, larger southward.
6.	Red chokeberry (Aronia arbutifolia)	2-4	White	Indifferent	Common from N. Y. southward. A. atropurpurea, with black fruit is worth while. A. arbutifolia has red fruit.
7.	Red bud (Cercis canadensis)	4-15	Pink-purple	Indifferent	Magnificent masses of color before the leaves appear. Sometimes almost a tree. Rare as a wild plant, but easily cultivated.
8.	Fragrant sumac (Rhus canadensis aromatica)	3-8	Yellowish green	Rocky woods	Will grow in unlikely places and an excellent shrub for wild effect. Flowers half hidden by compound leaves.
APRIL-MAY
9.	Shiny willow (Salix lucida)	10-18	Yellow-green	Low places	Will grow almost anywhere. S. myrtilloides a shrub 3½ feet, not in the trade, is handsome with yellow catkins.
10.	Prairie willow (Salix humilis)	3-6	Yellow-green	Dry places	Will grow almost anywhere. Flowers out much before the leaves. Useful only in mass effects.
11.	Sweet gale (Myrica Gale)	3-6	Incons-picuous	Swamps and bogs	Ash colored fruits effective all winter. Will grow in many other situations besides the preferred one.
12.	Bayberry (Myrica carolinensis)	3-8	Not showy	Indifferent	Grows equally well in sand loam, or swampy places. Leaves shining green, long persistent. Fruits whitish; all winter.
13.	Sweet fern (Comptonia asplenifolia)	3-5	Golden-brown	Dry hillsides	Golden catkins very showy before the leaves. Whole plant very fragrant. Can be grown almost anywhere.
14.	Beaked hazelnut (Corylus rostrata)	3-6	Brown-yellow	Indifferent	Along streams it makes effective screens and borders. The long beak quite distinct from No. 3. Occasionally 8 feet.
15.	Hoary elder (Alnus incana)	4-9	Greenish-brown	Moist places	Leaves pale green beneath. With Nos. 3, 4, 14 and 89, it can be used effectively along shores of streams and ponds.
16.	American black currant (Ribes americana)	3-5	Green-white	Shaded woods	R. lacustre and R. rubrum, the latter with reddish purple flowers are very fine. Neither in the trade.
17.	Juneberry (Amelanchier Botryapium)	5-12	White	Moist places	As individual plants very shapely, but rather ungainly in close formation. A. spicata (1-4 ft.) good, but not in the trade.
18.	English hawthorn (Cratægus Oxyacantha)	5-15	White	Dry hillsides	The May. Much cultivated and now run wild. The American C. rotundifolia common on L. I. and N. J., but not for sale.
19.	Scarlet thorn (Cratægus coccinea)	5-15	White	Thickets	The closely related C. Mollis, with scarlet fruits is effective in autumn. Not in the catalogues.
20.	Dwarf thorn (Cratægus uniflora)	2-8	White	Dry sandy place	Quite indifferent as to locality when cultivated. C. macracantha with long spines is often 10 to 15 feet. Not in the trade.
21.	Beach plum (Prunus maritima)	1-4	White	Sandy places	Fruit makes excellent jelly. Very successful near the sea. P. cuneata better grown near moist rocks.
22.	Sand cherry (Prunus pumila)	3-6	White	Dry places	Splendid in masses or small hillocks. Will grow in almost pure sand. P. Gravessii not in the trade.
23.	Prickly ash (Xanthoxylum americium)	6-18	Green	Shaded places	Will also grow in ordinary garden soil. The large compound leaves give splendid foliage effects.
24.	Bladder nut (Staphylea trifolia)	6-20	White	Indifferent	Usually about 10 feet in our latitude. The showy pods stay on most of the winter. Flowers not showy.
25.	Leatherwood (Dirca palustris)	2-5	Yellowish	Shaded places	In masses under trees or along shaded walks it is most welcome. Useful in a shaded rockery.
26.	Pinkster flower (Azalea nudiflora)	2-7	Pinkish-white	Shaded wood[5]	A blaze of color when planted in masses with other Azaleas. Can also be grown successfully in the open.
27.	Deerberry (Vaccinium stamineum)	1-4	Purple-green	Dry woods[[5]]	Flowers not showy, but purple fruits are attractive. Best not disturbed or transplanted after setting out.
28.	Red-berried elder (Sambucus pubens)	3-10	White	Cool woods	Easily grown in the garden but most successfully under trees or along the north side of the house.
29.	Black haw (Viburnum prunifolium)	5-18	White	Indifferent	After becoming a small tree. A magnificent snowy shrub in the spring. Fruits black.
MAY
30.	Silky willow (Salix sericea)	6-15	Yellow-green	Moist places	With the other willows useful for filling in low moist places. Leaves ashy beneath. Catkins showy.
31.	Wild gooseberry (Ribes Cynosbati)	3-5	Greenish-yellow	Rocky woods	Better grown in the shade and in rich soil. The bristly fruits are odd persistent features of this shrub.
32.	Black chokeberry (Aronia nigra)	3-8	White	Indifferent	Shiny black fruit stays on until December or January. Somewhat scraggy, except in masses.
33.	Mountain holly (Ilex monticola)	4-10	Greenish-white	Cool shade	Flowers not showy but the red fruits showy all the autumn. Do not attempt to grow in hot, dry places.
34.	Blue huckleberry (Vaccinium vaccillans)	1-4	Pink	Dry soil[[5]]	The profusion of tiny bell-like flowers appearing with the leaves makes this attractive. Fruits purple-black.
35.	Common lilac (Syringa vulgaris)	4-10	Lilac	Ordinary garden soil	Cultivated everywhere and sometimes escaped from gardens. There are scores of attractive hybrids and forms.
36.	American fly honeysuckle (Lonicera ciliata)	2-4	Greenish-yellow	Moist woods	Easily grown in ordinary garden soil, but prefers shade. Best planted along shaded walks.
37.	Fly honeysuckle (Lonicera Xylosteum)	2-6	Pinkish-white	Indifferent	Sometimes an escape from cultivation. The scarlet berries are showy in the early fall.
38.	Tartarian bush honeysuckle (Lonicera Tatarica)	3-8	Pinkish-white	Indifferent	L. oblongifolia with purplish-yellow flowers in May and June is attractive. Not in the catalogue.
MAY-JUNE
39.	Chinquapin (Castanea pumila)	5-8	Brownish-green	Dry soil	Apt to be affected with the chestnut blight. The long catkins and fruit are interesting but not showy.
40.	Magnolia (Magnolia glauca)	4-10	White	Swamps and bogs	Can also be grown very well on dry ground and in any garden soil. Fruits rose red.
41.	Common barberry (Berberis vulgaris)	3-8	Yellow	Common garden soil	Often an escape from cultivation. The well-known scarlet berries showy in autumn.
42.	Virginian willow (Itea virginica)	2-4	White	Moist places	When massed either alone or with Clethra alnifolia it makes attractive patches of white.
43.	Syringa (Philadelphus coronarius)	4-10	Cream-white	Indifferent	Many horticultural forms of this are in the trade. All are useful. Fruits brownish.
44.	Fetid currant (Ribes prostratum)	3-6	Greenish-yellow	Cool moist places	Not easily grown as it grows naturally on the cool mountain slopes. Fruits red.
45.	Opulaster (Spiræa opulifolia)	3-9	White	Indifferent	Splendid masses of flowers, as it is a profuse bloomer. Often from 3-6 feet wide and very bushy.
46.	Cockspur thorn (Cratægus Crusgalli)	6-14	White	Dry soil	One of the most commonly cultivated of our native shrubs. Very thorny and a good hedge plant.
47.	Pear haw (Cratægus tomentosa)	4-12	White	Indifferent	The dull red fruits cling on most of the winter. A profusely flowering shrub.
48.	Bastard indigo (Amorpha fruticosa)	4-10	Violet-purple	Rich soil	A gorgeous flowering shrub, which in masses is unrivaled. Repays good cultivation and care.
49.	Staghorn sumac (Rhus typhina)	6-15	Green	Dry places	Autumnal coloring magnificent. On a low hill very effective in large masses.
50.	American holly (Ilex opaca)	6-15	Greenish-white	Moist woods	Best transplanted in the spring, when all the evergreen leaves should be knocked or clipped off.
51.	Buckthorn (Rhamnus cathartica)	8-16	White	Indifferent	This and No. 52 both European shrubs that have run wild in this country. Neither is showy in flower.
52.	Alder buckthorn (Rhamnus Frangula)	4-11	Greenish-white	Indifferent	Its natural home is in swamps and bogs, but generations of garden culture has made it at home.
53.	Flame azalea (Azalea calendulacea)	2-7	Orange-yellow	Dry woods[[5]]	The showiest of all our native shrubs. Not very common in the wild state.
54.	Mountain laurel (Kalmia latifolia)	4-10	Red	Dry woods[[5]]	In masses under the shade of trees a wonderfully effective shrub. Prefers rich soil.
55.	Swamp huckleberry (Vaccinium corymbosum)	6-15	Pinkish-white	Swamps and wet woods[[5]]	Flowers not very showy, but the fruits are the finest of the tribe. Will not tolerate dry places.
56.	Low blueberry (Vaccinicum Pennsylvanicum)	1-4	White	Dry or sandy soil[[5]]	Often grows in almost pure sand in the pine-barrens. Neither flower nor fruit showy.
57.	Hobble bush (Viburnum alnifolium)	3-6	Pinkish-white	Cool, moist shade	The outer circle of flowers in each cluster very much larger than the inner. Does not like hot places.
58.	Dockmackie (Viburnum acerifolium)	3-8	White	Dry woods	Looks like a small maple tree. Useful as it will grow almost anywhere. Fruits black.
JUNE-JULY
59.	Hydrangea (Hydrangea arborescens)	4-9	White	Indifferent	Thoroughly hardy and often easier grown than the more showy exotic species.
60.	Meadow rose (Rosa virginiana blanda)	2-4	Pink	Indifferent	Along paths and roadsides it scrambles everywhere with apparent cultural indifference
61.	Sweetbrier (Rosa rubiginosa)	3-6	Pinkish-white	Indifferent	Well repays good treatment when it often becomes a bushy shrub 4 to 5 feet in diameter.
62.	Pasture rose (Rosa humilis)	1-3	Pink	Indifferent	The beautiful large petals very evanescent. It can be best grown in a moist place. Showy.
63.	Water ash (Ptelea trifoliata)	6-18	Greenish-white	Shade	Flowers inconspicuous but the compound leaves make it a good foliage plant. Wood very brittle.
64.	Black sumac (Rhus Copallina)	5-15	Greenish-white	Dry places	The large compound leaves a beautiful scarlet in the autumn. Profuse bloomer and fruits persistent.
65.	Inkberry (Ilex glabra)	3-6	Greenish-white	Moist woods	The more rare I. mucronata of swamps is interesting botanically but must be collected from the wild.
66.	Winterberry (Ilex verticillata)	6-18	Greenish-white	Swamps	Splendid scarlet fruits cling on in large clusters most of the winter. Often easily grown in the garden.
67.	Strawberry bush (Euonymus americanus)	3-7	Greenish-pink	Low woods	Flowers small and inconspicuous but followed by red fruits that last until December. A slender plant.
68.	Burning bush (Euonymus atropurpureus)	8-15	Purple	Indifferent	European shrub much cultivated and now widely established as a wild plant. Fruits red and showy.
69.	New Jersey tea (Ceanothus americanus)	2-6	White	Shade	Effective as massed plantings. The leaves the source of tea in Revolutionary times. A profuse bloomer.
70.	Kinnikinik (Cornus Amomum)	3-10	White	Indifferent	Purple twigs effective in winter. The reddish-twigged C. asperifolia effective but not on sale.
71.	Red osier dogwood (miscalled kinnikinik) (Cornus stolonifera)	3-12	White	Indifferent	Twigs reddish-purple; and fine in masses for its winter color harmonies. Easily grown from cuttings.
72.	Cornel (Cornus alternifolia)	3-10	White	Indifferent	The bright green twigs which keep their color all winter make it attractive grouped with Nos. 70 and 71.
73.	Swamp honeysuckle (Azalea viscosa)	3-6	Pink and white	Swamps[[5]]	Rather shy of dry places but easily replaced in such places by the A. canescens, which must be collected.
74.	Rhododendron (Rhododendron maximum)	4-18	Rose-white-purple	Woods[[5]]	Old plants, almost treelike, should never be disturbed. Be careful to nip all fruits as soon as they appear.
75.	Sheep laurel (Kalmia angustifolia)	1-3	Purple-crimson	Low, moist places[[5]]	The rare K. glauca, not in the trade, is very much worth while. Neither is happy in open dry places.
76.	Leucothoe (Leucothoe racemosa)	5-12	Cream-white	Swamps[[5]]	The glossy practically evergreen leaves make an effective winter showing. Can be grouped with Nos. 74, 77 and 78.
77.	Staggerbush (Pieris Mariana)	1-4	Pinkish-white	Sandy soil[[5]]	Isolated plants are apt to be sprawling, but when massed the delicate flowers make attractive patches of color.
78.	Privet andromeda (Xolisma ligustrina)	4-9	White	Moist places[[5]]	Leaves partially evergreen, and dark glossy green in color. A profuse bloomer with persistent fruits.
79.	Elderberry (Sambucus canadensis)	5-15	White	Indifferent	In large clusters most effective as a screen. Will grow very well along a stream or pond. Fruits “mussy.”
80.	Cranberry bush (Viburnum Opulus)	3-12	White	Indifferent	Profuse masses of flowers and large clusters of scarlet berries make it most useful all the year.
81.	Withe rod (Viburnum nudum)	2-8	White	Indifferent	The C. pubescens of rocky woods equally good but not offered for sale. Fruits blue-black.
82.	Appalachian tea (Viburnum cassinoides)	2-8	White	Moist places	V. Lentago with black fruits useful, but must be collected. Leaves of V. cassinoides glossy and dark green.
JULY-AUGUST
83.	Hard hack (Spiræa tomentosa)	1-4	Pink-purple	Low ground	The ashy underside of the leaves, contrasted with the pinkish-purple flowers is a novel combination.
84.	Shrubby cinquefoil (Potentilla fruticosa)	2-4	Yellow	Moist places	One of the yellow-flowered shrubs that are used. Sometimes winter-kills near New York.
85.	Swamp rose (Rosa Carolina)	4-7	Rose-colored	Moist places	Can also be successfully grown in ordinary garden soil, well manured. Flowers soon withering in open sunlight.
86.	Smooth sumac (Rhus glabra)	3-12	Greenish	Dry places	Grouped with Nos. 49 and 64, it gives a wild touch to the landscape. Autumn color gorgeous.
87.	Hercules’s club (Aralia spinosa)	6-15	White	Low ground	Large compound leaves 3 to 4 feet long, make this the foliage plant par excellence. Flowers inconspicuous.
88.	Sweet pepper bush (Clethra alnifolia)	3-8	Cream-white	Low ground	Fragrant flowers followed by persistent fruits, a sturdy habit and bushy outline make this a favorite.
89.	Buttonbush (Cephalanthus occidentalis)	5-15	Cream-white	Moist places	Best not attempted much away from water, and in such situations often becoming almost treelike. Flowers fragrant.
90.	Snowberry (Symphoricarpos racemosus)	2-6	White	Indifferent	The flowers are not showy but the conspicuous white berries stay on all winter, thus valuable for winter effect.
91.	Coralberry (Symphoricarpos vulgaris)	1-4	Pink	Indifferent	Much like the preceding but the red fruits are not so persistent. Forms a wide-spreading bush.
SEPT.-DEC.
92.	Witch hazel (Hamamelis virginiana)	5-15	Yellow	Moist shade	Flowers later than any other native shrub, often after all the leaves have fallen off, and the first frost arrives.
93.	Heather (Calluna vulgaris)	1-2	Pinkish-white	Sandy places	Rather shy in its few American localities. Near the coast from Massachusetts to southern New Jersey it should do well.
94.	Groundsel tree (Baccharis halimifolia)	2-5	Whitish-green	Dry soil	Best transplanted in the spring as its late flowering makes autumnal activity too great for easy transplanting then.

Rhododendrons and azaleas, hundreds of varieties of which are known and admired by all garden lovers, are mostly derived from Asiatic species, and under the new law have become rare and expensive in this country. A few American nurserymen are able to propagate them so that we can still get plants of these showiest of all shrubs. They should not be used in regions where there is scant rainfall, very hot summers, high winds or extreme winters. Their use is practically confined to the region east of the Alleghenies.