3 DECEMBER 1921, Page 19

' 1HJ•: TREES OF LONDON.* EVERYONE admits now that the planting

of trees adds to the health as well as to the beauty of a city. The only question is What trees ? It is curious how inadequately this subject has been studied even by some of the officials who are responsible for the planting. In a city a tree has a higher adventitious value, or a greater " utility " in the economic sense, than belongs to a tree in the country. In a well-wooded part of the country the removal of a few trees would make no difference and might, indeed, do good by giving more air space to the survivors—the

margin of utility " in trees has been reached ; but in a city a single tree in a thriving condition and in a well-chosen spot may make all the difference to the prospect of a whole street. The bursting of that tree into leaf when spring comes is an event ; it entrances thousands of eyes. Trees which have this special value for the populations of cities should be chosen and tended with extreme care, for a misshapen or moribund tree is a disappointment and an offence, whereas a tree that prospers is a delight at every season of the year. It is a messenger from other spheres. It is a delight when it is pushing out its leaves, a delight when it is in its full June splendour, and a delight when the delicate tracery of well-shaped branches is seen against the winter sky. And what is more charming than an avenue of trees in a busy thoroughfare ?

The plane tree is, of course, the commonest tree anywhere near the heart of London. It defies the smoke, and it reaches a great and sometimes a. majestic size. There is a popular belief that the plane prospers because it automatically cleans itself by annually shedding its bark. Mr. Webster, the author of the instructive and suggestive book before us, repudiates this belief and asserts that neither the shedding of the bark nor the smooth- ness of leaf surface accounts for the success of the plane in London. He points out that other trees which do not shed their bark and have rough foliage do just as well. Probably the soil is the principal factor. The fact that the plane will not prosper merely because it can resist chemical impurities seems to be proved by its failure in Sheffield and Manchester.

We agree with Mr. Webster that the plane has been rather overdone in London. In spite of its strength it is not the ideal

• London Trees. By A. D. Webster. Illustrated. London : The Swarthm ore Press. [15s. net.]

tree for confined spaces—for example, where it shuts out tlie light from houses or is used for avenues—because it has to be lopped in order to keep it within manageable size. What is more annoying to anyone who appreciates the natural shape of trees than to see a tree artificially made to conform to the require- ments of a municipal authority ? The right solution would seem to be to use more trees which can reach their full natural growth without getting out of hand. There are many of these. Almond trees, for instance, will grow almost anywhere, and the spring blossom is magnificent. The catalpa is not sensitive to smoke nor is the fig tree. Again, the Judas tree, which is so little planted in England as to be regarded almost as a rarity, is a tree for all places. When we reflect upon the interesting legends connected with the Judas tree, and the strange bursting forth of the flower directly from the trunk as well as from the branches, we ask why we aro not allowed to have more Judas trees in London. The Sumach, too, might be much more generally planted, and Mr. Webster thinks that a strong case might be made out for the tamarisk. But the most smoke-defying tree of all is the common elder. This tree is somewhat despised no doubt in the country because the rustic worker regards it as the unruly member of his hedges. But this very mutinous and invincible growth is just the thing to commend it to Londoners. Its spring blossom and the dark berries of the autumn are alike charming, and it does not grow too large.

But it must be admitted that, unless it can be grown in new forms, it is not a tree you can walk under.

All these possibilities are well worth consideration, because it is obvious that the large trees which were planted in Central London when it was a smaller and cleaner place no longer thrive. The cedar, the beech, the oak, the Scotch fir, the sweet chestnut, the horse chestnut and the lime are nearly all moribund. As for elms, they are dangerous trees owing to their nasty habit of dropping great branches without warning. All the same, we would rather risk the fall of a branch than see the elms disappear from Kensington Gardens and elsewhere.

The plane is really the tree for parks and large open spaces. The pseudo-acacia, or Robinia, is also a tree which stands a great deal of heat and smoke, but of course, like the plane, it requires room. Cobbett was quite wrong when ho predicted that this tree, which he said was " absolutely indestructible by the powers of the earth, air and water," would become more common than

the oak, but that is no reason why we should not have many more Robinias in London. The Ailanthus is another tree which will grow splendidly in any part of London where there is room for it. Some of the larger specimens are in Bloomsbury Square,

one of them being seventy feet high. There are also fine examples in Lincoln's Inn Fields, in the Temple Gardens, and in the public gardens at Poplar :— " Growing within a stone's throw of the Royal Mint are half a dozen trees of the Ailanthus which average fifty foot in height, with massive stems from five to six feet in circumference at a yard from the ground. It is well known that the chemical impurities given off at the gold-refining works at the Mint are amongst the most deadly to tree and shrub life of any in the Metropolis. That the Ailanthus is even better suited than the Plane for the most smoky parts of London is quite evident from the way the tree succeeds in many parts of the East End, and in the confined and dirty precincts of the Church of St. Magnus the Martyr it has quite ousted the Plane from the field. In the City, as at Finsbury Circus and other parts, the Ailanthus grows with the greatest freedom. The Ailanthus is readily distinguished from any other tree, especially when leafless, by the stout, thick growths and comparative absence of branchlets, as well as by the dark-grey colour of tho comparatively smooi It bark. Few trees possess such elegant foliage and graceful habit as the Ailanthus, which with its towering growth would seem to justify its popular name, ' Tree of Heaven.' " A great merit of the Ailanthus is that it is immune against all attacks by insects.

There is no reason why we should not have many more ash trees in London. No doubt the ash is not regarded as one of the most ornamental trees, and there also seems to be a belief that it is unsuited to the London atmosphere. This, however, is at once disproved by the fine specimens in Cavendish Square. It will be rather a shock to some London antiquarians to read that what is known as Bacon's catalpa in Gray's Inn was probably not planted by Bacon at all. Moreover, it appears that it is not the oldest nor the largest in London. Mr. Webster says :- " That Bacon when appointed Master of the Walks at Cray's Inn in 1597 planted this Catalpa is also open to doubt, the introduction of the tree not taking place till 1726, or fully a century and a quarter later. There are two Catalpas of about equal size

growing in the gardens at Gray's Inn, to one of which is attached a tablet with the following inscription : Catalpa tree said to have been planted by Francis Bacon, when Master of the Walks, Anno Domini 1598.' Owing to its recumbent mode of growth it is difficult to give exact measurements of this tree. The main stem, which is eighteen inches in diameter, rests on the ground and is partly buried in the soil for about nine feet in length, after which an upward position is taken, the girth at this point being five feet. As near as can be ascertained the trunk girths seven feet at ground-leveL The branches extend in a somewhat horizontal direction, and being of considerable length and weighty are supported by a number of stout props, one of the branches which is buried in the soil being probably rooted. The total height of the tree is about twenty-eight feet and the branch spread forty-five feet. The other Catalpa is growing on the opposite side of the garden, and is said to be a seedling from Bacon's tree. The branch spread of this specimen extends to sixty feet, while the stem at ground level and at three feet girths 6 feet 9 inches and 5 feet 10 inches respectively. It is about forty feet high and in splendid health, but like the parent tree the heavy branches, four in number, take a somewhat recumbent and horizontal style of growth and are propped for support. Both trees are growing on a mound, or more probably the soil has at some time been banked up around the leaning stems."

However that may be, Gray's Lan Gardens have undoubtedly one of the largest and noblest plane trees in London. It is known as the Wallace tree. It was planted some fifty years ago and is more than seventy feet high. Its trunk is excep- tionally gnarled even for a plane, and there are several other

first-rate planes in the same gardens.

On the whole, deciduous trees do considerably better than ever- greens in London, though it is still thought by some people that evergreens are particularly suitable to towns. Nothing surely is more depressing to look at than a really shabby evergreen.

We will end by strongly supporting Mr. Webster's appeal for more experiments. By special request there have recently been introduced into London some flowering trees that have done well in American towns. There are great hopes of these, which are of the prunus and pyrus typo.