The common lilac, Syringa vulgaris, and its hundreds of forms and hybrids have always been garden favorites.
Their beauty and fragrance have led horticulturists to expect too much from the approximately 20 late-blooming lilac species that have only recently been introduced into gardens.
As a result, there has been rather severe criticism of them as a whole.
They deserve a more fair judgment based on what they are in themselves, rather than on comparisons with some favorite lilacs like Vestale, President Lincoln, Capitaine Baltet, or Ludwig Spaeth.
Let us admit, at once, that they do not have the fragrance of these varieties or their color range.
Well, neither do our forsythias, our spireas, or our deutzias, yet we judge them for their qualities.
I shall try to judge the late blooming Syringa species in this way.
Distinct Syringa Species
About half a dozen of the 20 or so species are distinct enough and beautiful enough to warrant planting in larger suburban places.
Syringa Josikaea
Only one of these, Syringa josikaea, the Hungarian lilac, is European in origin. It is the best known and the longest in cultivation.
It is a strong, coarse-growing twiggy shrub to 12 feet or more in height and proportionately broad.
It has attractive, rather glossy foliage and stands pruning and clipping exceptionally well. It is often used for dense screens or hedges.
The flowers, which come in early June in the latitude of New York City, a rather deep lilac, or violet lilac in color, are borne freely on attractive spikes.
It, like most others, has to be a rather pleasing fragrance. Though not the fragrance associated with the word “lilac,” it is much more like that of various species of privet, Ligustrum, to which the lilacs are closely related.
It must be remembered that many people do not care for the over strong odor of some privets.
It should be remembered, also, that the Hungarian lilac became an established garden favorite very soon after its discovery and introduction by Baroness Josika in 1830, long before any of the other late-flowered lilacs were known.
It is a much more characteristic inhabitant of old gardens than of new ones.
All the other late-flowering lilacs are from China or nearby Manchuria, Korea, and Japan. Syringe rosa was discovered as long ago as 1740 though it was not introduced to gardens until 1882, when the Arnold Arboretum received and distributed plants.
It is commonly seen about 10 feet high, rather stiffer and less twiggy than josikaea, and with much paler flowers, usually on the pinkish side of lilac fading out to whitish.
Syringa Sweginzowii
Syringa sweginzowii, introduced in 1894, is similar in size but has reddish lilac handsome flowers.
Distinct from these three is Syringa reflexa, introduced in 1904. As the name indicates, it has flower spikes that droop rather than stand erect.
It makes a most graceful shrub and is attractive on the border or as a specimen. Its flowers are on the pinkish side of lilac.
Syringa Pubescens
Syringe pubescens may be mentioned here even though its bloom season overlaps the later common lilacs. It is, therefore, technically a midseason and not a late-blooming lilac.
It was introduced by the Arnold Arboretum in 1882 and grows about 6’ feet high, producing pale lavender or lilac flowers. It has been confused with the next species.
Syringa Microphylla
Syringa microphylla was introduced in 1910. Its botanical name refers to its small leaves, but much more important to the gardener is the size and shape of the bush.
It grows only about 6’ feet high but will spread twice as much. It is both unique and attractive.
More important, perhaps, it fits into places where taller plants would be unsuitable.
Its pale lilac flowers are earlier than the others in this group but, even so, distinctly later than the common lilac.
Syringa Urticaria Japonica
To these six fine shrubs should now be added the tree lilac.
Syringa urticaria japonica, is distinct not only because it becomes a true tree up to 80’ feet or more in height but also because it is the latest to bloom.
Its attractive bark is a feature in winter, its large leaves are beautiful all summer, and its large spikes of white flowers are always a source of amazement to those who think of lilacs only as bushy plants.
It was brought from Japan in 1878, and fine specimens are to be seen in many of the older gardens of our Atlantic states.
The Amur lilac, a botanical (not horticultural) variety, and the closely related Pekin lilac, Syringa pekinensis, are not so tall, showy, or important.
These species, it seems, are important plants for those with the needed space. Botanically inclined gardeners profess to see much virtue in at least 10 others.
Syringa Emodi
The first of these, Syringa emodi, was introduced from the Himalayas in 1840 and may not be hardy in the extreme North.
The others are “novelties” in that they were brought into our gardens during the first and second decade of the 20th century, and time has not permitted propagation and distribution on an extensive, commercial scale. Therefore, they are not widely known nor, indeed, often seen.
Careful observation of them in the Swarthmore collection during the past 10 years, coupled with fleeting observation on visits to the Arnold Arboretum, Rochester.
Other great collections lead me to agree wholeheartedly with Dr. Wyman’s evaluations of them in his new book, Shrubs and Vines for American Gardens.
I feel as he does that Syringa emodi, yunnanensis, wolfs, komarowii, tomentella, julianae, velutina, meyeri, potanini, pinetorum, and pinnatifid do not warrant any important place in the gardens of those who plant for distinctness – distinction and beauty however interesting they may be to the collector and the botanist.
Most are either too close to or inferior to those I have mentioned. They interest me, and I am glad to have them in the Swarthmore collection, but we do not need them for most garden purposes.
This is not to condemn them as one prominent writer did some years ago, but rather to realize that most gardeners must limit themselves to a reasonable number of kinds of any one group.
Dealing With Wild Species and Types
A few named selections, a little paler or a little darker than the type, are available in nurseries, but these I have seen have not seemed to be outstanding.
New explorations may, in time, discover superior dons of wild types.
Most promising at present are the prospects of hybrids. We already have the hybrids of villosa, josikaea and sweginzowii crossed with reflexa.
We have, in fact, too many of them that are too much alike, but after the best ones are sorted out and recrossed with each other and with other species, no one can tell what startling plants and flowers may be developed.
That, however, is another story. What I have tried to do here is to point out a few of the good garden characteristics of a few of the wild species of lilacs.
44659 by John C. Wister