August 6, 1910 



HORTICULTURE 



165 



Notes From the Arnold Arboretum 



It i:^ to be wondered at that such a handsome little 

 shrub as the Heather, CaUuiia vulgaris, has been so 

 much neglected by planters in this country'. If seen as 

 a single plant, it is, of course easily passed by, as it has 

 no striking ornamental features, but in masses it is 

 highly effective. Whoe\er has had the opportunity to 

 see in northern or centi'al Europe this Heather covering 

 with its purple carpet wide stretches of moorland, sandy 

 plains or gravelly slopes, sometimes as far as the eye 

 can see, must consent that the effect is charming and it 

 is not an effect of short duration. The masses are beau- 

 tiful from the time when the fiower-buds appear in July 

 and the dull green heath becomes from day to day more 

 highly colored until the whole is aglow with purple, to 

 the time when in September the color of the heath 

 changes tp a soft brownish tint heralding the coming 

 autumn.' The fact that well established colonies of this 

 plant have been found along the northern Atlantic coast, 

 tends to show that also in this country it finds congenial 

 conditions and may thrive well. It can be employed' 

 with advantage to cover barren sandy or gravelly soil, 

 banks and slopes, and it also grows well in peaty and 

 even swampy soil. It is well adapted for bordering Rho- 

 dodendron groups, as it is used in the Arboretum, and 

 for planting in rockeries and similar places. In Europe 

 it has been always a favorite plant and a large number 

 of varieties, at least twenty-five, are found in cultivation. 

 To the most distinct forms belong the pure white varie- 

 ties, of which Calluua lulgari.s var. alba is the best 

 known : another wliite form is var. Searlii differing in its 

 later tiowering time, October and Xovember. A form 

 with flowers of a deeper purple is var. rubra, while var. 

 tomentosa differs in the grayish green color of its foliage, 

 caused by a grayish pubescence. Distinguished by their 

 taller and more vigorous growth are var. elata and var. 

 Alportu, the latter with bright rosy carmine flowers. 

 The opposite tendency is shown by C. vulgaris var. pyg- 

 maea which forms low almost moss-like tufts. There is 

 also a handsome variety with rose-colored double flowers, 

 C. vulgaris var. plena. The heather is easily raised in 

 quantities from seed which is like other fine ericaceous 

 seed best sown in pans filled with sandy peat and cov- 

 ered not at all or very slightly or covered with sphagnun 

 to be taken off as soon as the seeds germinate. The va- 

 rieties grow readily from green-wood cuttings in summer 

 imder glass. 



Since a few years we cultivate at the Arboretum a 

 form of the Sweet Elder, Sambucus canadensis var. max- 

 ima which attracts attention by its immense flower clus- 

 ters measuring from ten to eighteen inches in diameter. 

 This variety is very effective and flowers as a rule some- 

 what later than the type. It is particularly suitable 

 for planting on the banks of streams and ponds. 



Among the strmmer-floM-eriug trees Koelreuteria pan- 

 iculata ought to be brought to attention as a little 

 known, bttt very attractive small tree. It is a low, round- 

 headed tree with bright green and large, much divided 

 foliage, which gives the tree quite a graceful appearance. 

 The bright yellow flowers appear during July and 

 August in large upright clusters at the end of the 

 liranches and are very eft'ective. The Koelreuteria has 

 proved quite hardy at the Arboretum, only in very severe 

 winters the branches are sometimes partly killed back. 



A handsome shrub now in bloom, but seldom seen in 

 our parks and gardens, is Stuartia pentagyiia remarkable 

 for its large white cup-shaped flowers which measure 

 three to four inches in diameter: these appear on short 



stalks in the axils of the leaves and are therefore often 

 partly hidden by the foliage which makes the shrub 

 Komewhat less showy, :is it otherwise would be with its 

 unusually large flowers. The foliage also is handsome, 

 the bright green oblong leaves measuring four to five 

 inches in length, and assumes bright orange and scarlet 

 tints in autumn. The shrub has proved hardy at the 

 Aiboretum where it forms a spreading bush about five 

 to six feet high, while in its native habitat, the southern 

 states, it may reach a height of fifteen feet. 



Roses at the Brussels Exposition 



The Belgium World's Exposition now being held at 

 Brussels, although not so pretentious as the one held 

 in Chicago, offers a splendid collection of all the latest 

 inventions and goods from all nations. 



I am sorry to say that the United States alone seems 

 to have neglected its opportunity in every way, as the 

 small space devoted to the States would not make even 

 a fair sized hall. For Horticulture nothing is shown, 

 owing probably to the fact that it would seem somewhat 

 like shipping coals to Newcastle. Yet when passing 

 through the main entrance of the principal building, one 

 is confronted by a large flower booth, containing most 

 of our latest and finest carnations — such as Enchantress, 

 Lawson, Winsor, Beacon, White Enchantress, Alma 

 Ward, Pink Enchantress, and several older varieties, all 

 fine specimens. It would seem that our carnation 

 growers might have made here a display to advantage 

 in plants, especially as we come here to buy most of our 

 hybrid roses, bulbs, rhododendrons, lilacs, azaleas, etc. 



The landscape features were beautifully carried out, 

 in the limited space allowed for the parking of the 

 magnificent buildings. Every advantage was taken to 

 enhance the setting for the buildings, and the gardeners 

 and landscape architects performed their part to per- 

 fection. As my time was limited I devoted it to the 

 rose section out-of-doors — the indoor show had already 

 been held before I arrived. They told me it was very 

 fine, and from the blooms seen in the open I can readily 

 believe it. The sight of thousands of roses of all 

 varieties in bloom at once in the rose garden was a great 

 treat, and presented a beautiful landscape effect. 



The site chosen is admirably located, not only for 

 viewing the roses, but also they are protected first ty 

 the large buildings about them and-^being in a sunken 

 garden — by the surrounding banks. These banks, 

 edged with lawn grass, were further utilized to show the 

 dwarf varieties and this gave a setting of green to en- 

 hance the color of the flowers. The area covered by this 

 exhibit was fully two acres. The parterre was laid out 

 artistically with walks around the whole, and winding 

 paths with grass borders between. Each firm exhibiting 

 liad his own individual space. 



All plants were properly labelled with a neat porcelain 

 label, with the name stamped in black ink, the firms' 

 names being also of uniform size, but larger, so that ni) 

 great advertising signs were seen to mar the general 

 effect. Every exhibitor received the same treatment, 

 thus giving equal rights to the small as well as the large 

 grower. 



Owing to the continuous rain the roses were not at 

 their best, but, even so, they were a delight to all lovers 



