396 



Garden and Forest. 



[August 13, 1890. 



length as to greatly interfere with cultivating the plants and 

 gathering the fruit unless they are dwarfed in some way by 

 treatment. By permitting them to grow to their full length, 

 and then cutting them back to a convenient stature, we should 

 remove one-half or more of the fruit-buds, and thus mate- 

 rially reduce the crop. We must prune them in such a way 

 that while we keep them down to a size that is convenient for 

 working among them, we also preserve the flower-buds. To 

 accomplish this we pinch the terminal shoot at the height of 

 two to two and a half feet. This causes the buds in the axils 

 of the leaves to develop into branches, and instead of a single 

 cane six or eight feet in length we have half a dozen branches 

 two feet or less long. 



To the beginner it appears almost absurd to pinch a Rasp- 

 berry-cane at the height of two feet. It seems as if the cane 

 has but just commenced to grow, and that to pinch it at that 

 height will prevent it growing taller. But it should be remem- 

 bered that there are several nodes at the top of the stem that 

 have not attained their full length, and which will continue to 

 elongate for some days after the tip has been removed. 

 A cane pinched at two feet will attain an ultimate height of 

 three feet, which is sufficient. 



It has often been recommended to pinch the branches when 

 they have attained the length of a foot from the main cane. 

 The wisdom of this is quite doubtful, at least in regions of 

 severe winters. The effect of it is to cause axillary buds upon 

 the branches to develop into shoots, and this will take place 

 so late in the season that they have not time to make much 

 growth, and, being immature, they are liable to kill back 

 badly during winter. The result is that the buds that should 

 have remained dormant until spring to furnish the flowers for 

 the crop have been forced into growth in late summer, while 

 the tender buds upon these immature shoots — all that are 

 now left to furnish the crop — have either been killed outright 

 or severely weakened by the winter. It is doubtless, in the 

 majority of cases, better to let the branches from the main 

 cane grow undisturbed until autumn and then cut them back 

 as far as seems desirable at the spring pruning. 



The canes of the Red Raspberry [Rubies strigosus) do not 

 attain such great length as those of the Black-Cap type, and so 

 do not, as a rule, need pinching in summer. When vigorous 

 growing varieties like the Cuthbert are planted id rich soil the 

 canes sometimes attain an inconvenient height. In such cases 

 they may be pinched like those of the Black-Caps, but the 

 pinching will tend to stimulate the growth of suckers, an evil 

 which needs no encouragement, because it is apt to be ex- 

 cessive in rich soils even without the pinching. It would pro- 

 bably be wiser to substitute a weaker growing variety, or else 

 to remove the plantation to poorer soil. 



The reasons given for pruning the Black-Cap type of Rasp- 

 berries will apply as well to the Blackberry. „ 



University of Wisconsin, Madison. E. S. (-rOff. 



Disa grandiflora. 



T > HE York nurseries have long been famed for the cultiva- 

 -*• tion of this superb Orchid, which, when well grown, is 

 very much superior to all other terrestrial species. It is, how- 

 ever, often a failure in English gardens, even when managed 

 by growers of undoubted ability. The treatment which an- 

 swers so admirably with Messrs. Backhouse, of York, appears 

 simple and within the means of any one possessing a cold- 

 house or frame. At a recent visit there I found over 1,000 

 spikes of the flowers of this Disa all in a house, or a portion 

 of a house, some twenty yards long. Many of the spikes 

 measured a yard in height, and five flowers on a spike were 

 not infrequent. The house is a low span, running from north 

 to south, with a central path and brick beds about four feet 

 wide. The surface of the bed is about eighteen inches from 

 the glass at the back, and is formed of sandy peat, with large 

 pieces of soft sandstone scattered through it. The depth of 

 the soil is about six inches, below which are clinkers and brick 

 rubble. The best of peat is used, and the plants are always 

 placed against a large piece of sandstone, an important point 

 not to be overlooked. In this they soon establish themselves, 

 sending out runners freely in all directions, so that if allowed 

 to remain undisturbed for two or three years each plant be- 

 comes a many-headed tuft. The soil is kept moist, but not 

 excessively so, injury resulting from too free watering even in 

 the case of this plant, which in its South African haunts is 

 often semi-aquatic. The house is shaded all day by a thin 

 canvas blind, and the whole of the roof glass is drawn off both 

 day and night in all favorable weather. 



This is the whole secret so far as Messrs. Backhouse can re- 

 veal it. On the other hand, some cultivators grow this Disa 

 well by planting it in a mixture of peat, sphagnum and brick 



rubble or sand. But not even on Table Mountain is it possi- 

 ble to see a more glorious display of flowers than is produced 

 annually in the famous York nurseries. 



When we come to examine the plants we find considerable 

 variety in the form and colors of the flowers far beyond any- 

 thing described as occurring in nature. This variety in culti- 

 vated plants is accounted for by the fact that both in Messrs. 

 Backhouse's hands and elsewhere in England seeds have been 

 matured and large numbers of seedlings obtained from them. 

 Sometimes it is possible to obtain strong flowering plants of 

 this Disa in three years from seeds. According to Bolus, Tri- 

 men, and others who have studied the habits of D. grandiflora 

 at the Cape, wild plants are not known to mature seeds. Tri- 

 men stated that he had never found any trace of insect agency 

 in this plant, and Bolus, -in his "Orchids of the Cape Penin- 

 sula" (1888), says, on this point, "I have never seen a matured 

 seed vessel, nor been able to detect any insect employed in its 

 fertilzation. On its native mountains it has a wide range of al- 

 titude, grows vigorously in dense masses, or at least several 

 together, being apparently propagated exclusively by the forma- 

 tion of new tubers, and isolated plants (such as might be ex- 

 pected if it seeded freely) are rarely to be seen. Considering 

 the brilliant colors of the flowers these facts are remarkable, 

 and seem to point to the extinction of the insect by which this 

 species was originally fertilized." "Artificial fertilization and 

 selection, although only comparatively recently applied to this 

 species, have already produced remarkable results in the 

 shape of variety. If this plant could be grown with the same 

 ease and success everywhere as it is by Messrs. Backhouse we 

 should probably in time get a race of varieties as diverse in 

 character as Zonal Pelargoniums." 



Kew. * W. IV. 



A Few Strong-growing Adiantums. — II. 



A HANDSOME variety of Adiantum trapeziforme is known 

 •**- as Cultratum, and it bears some resemblance to the 

 type, but has smaller pinnules. The young fronds, when de- 

 veloping, are brownish and sometimes tinted with pink, finally 

 turning to dark green with shining black stipes, and frequently 

 attaining a height of three feet or more. This peculiar shad- 

 ing of the young fronds is one characteristic which distinguishes 

 this variety from A. trapeziforme, as the latter almost inva- 

 riably comes up pale green in color. It may be said, how- 

 ever, that the tinting of the young foliage in Adiantums is not 

 always a reliable characteristic to judge by, as differences in 

 exposure as to light or shade may make some difference in 

 the color of some varieties, though not in all. 



A. digitatum is another fine species, and, like the pre- 

 ceding, is a native of Brazil and some other portions of 

 South America. It throws up its light green fronds on slen- 

 der footstalks from one and a half to two feet in height. The 

 fronds are rather irregular in general outline, and are usually 

 three times divided. A. digitatum grows best in a warm house 

 temperature, and, as the fronds are rather brittle, it generally 

 requires a few stakes to keep it in form. It is a very distinct 

 species, having pinnules from half an inch to an inch in diam- 

 eter, and when well grown makes a handsome specimen. 



Still another fine Brazilian species is A. intermedium, also a 

 stove species, and a notably good one, its massive-looking, 

 dark green, bipinnate fronds, with somewhat woolly stipes, 

 being both ornamental and useful, as they last well when cut 

 and placed in water. While yet small, A. intermedium is a 

 good species for window-ferneries, and, as the spores come 

 up freely, it may be readily had for this purpose. This spe- 

 cies has as synonyms A. Brasiliense and A. triangulatum. 



A. Wilesianum is a very handsome species from Jamaica, 

 and it is not very common, probably from the fact that it does 

 not produce so many spores as some other species, and the 

 propagation of it thus depends in a measure on division of the 

 crowns. A. Wilesiatium is somewhat similar in general ap- 

 pearance to A. cardiochlcEJta, though abundantly distinct from 

 the latter. It bears broad fronds that are two feet or more in 

 height and pale green in color. The fronds have shining 

 black stipes which stand up well without support and form 

 an admirable contrast to the delicate coloring of the pinna;. 

 This species will also be found to grow best in a temperature 

 of about sixty degrees. 



A. tetraphyllum gracile is another effective species, the 

 fronds averaging from one to One and a half feet. The young 

 fronds of this species are specially attractive, being bright pink 

 in color, which gradually fades as the frond attains its growth, 

 when it becomes dark green. The fronds of this variety are 

 easily injured by excessive dampness, and it is best therefore 

 to keep the water off the foliage as much as possible, though 

 an abundant supply at the root is necessary. This species, 



