96 



HORTICULTURE 



January 27, 1906 



Nature's Teaching 



The question whether nature is the best tutor in Hor- 

 ticulture is receiving some attention from horticulturists 

 in Europe. 



Do cacti demand the dry arid atmosphere such as 

 they are subjected to in their Mexican home for a good 

 part of the year, or would they thrive in a moist genial 

 atmosphere, such as most plants love ? We have had 

 considerable difficulty trying to grow certain species 

 of cactus in a house especially built for them, where 

 nearly as possible nature's example was followed and 

 have been surprised and somewhat mortified to see in 

 the window of an ordinary dwelling house the same 

 species in splendid health. The lady whose property 

 and charge they were, when questioned regarding their 

 treatment, could only say that they received no partic- 

 ular attention and were watered perhaps every day 

 summer and winter. 



The question which occurs to us is : Do these plants 

 really need the condition found in nature? At the 

 present time certain orchidists in England have got 

 ahead of their brethren and are demonstrating that al- 

 though the majority of orchids have pseudo-bulbs that 

 must not be taken as an indication that the plants must 

 have a period of rest, which generally means a shriv- 

 elling of the pseudo-bulb and consequently a loss of 

 vigor to the plant. "Keep them going" is the motto of 

 this school who also claim that odontoglossums are 

 more healthy if given a warmer winter treatment than 

 is generally considered necessary or advisable. 



Hybridization it is claimed has taught the observant 

 cultivator that a seedling was more vigorous and de- 

 veloped quicker under moister and warmer conditions 

 than was considered good for its parents. Whether 

 these conditions in winter would help odontoglossums 

 to stand the American summer better is debatable. 

 Odontoglossums do not like anything approaching a 

 dry atmosphere and should not be allowed to become 

 very dry at the roots. A dry atmosphere is conducive 

 to thrips which is one of the worst insect pests the 

 orchid grower can be troubled with. 



The writer has had the charge of a collection of or- 

 chids grown for botanical purposes with most of which 

 very little and in many cases no data as to the natural 

 conditions under which they are found, is furnished 

 and, as they are indescribed species, no data is obtain- 

 able. After a good deal of experimental treatment I 

 have demonstrated to my own satisfaction that a relative 

 humidity of from 70- — 80 degrees at all seasons is de- 

 sirable and that even when a plant is not actually 

 growing these conditions are helpful except in the 

 case of a few deeidious kinds such as ealanthes, liparis, 

 etc. Moisture and warmth do not as a rule cause the 

 plants to make premature growth. In some cases the 

 period of rest is short, but as a rule most growth com- 

 mences in the lengthening of the days of February and 

 March, a fact which is somewhat remarkable in a house 

 containing five hundred or more species from all parts 

 of the world. 



The old idea of punishing an orchid to induce flowers 

 has become old-fashioned and is little practised. It was 

 thought that Odontoglossnm citrosmum would not de- 

 velop flowers unless water was withheld from the time 

 the young growth appeared until the flower spike was 

 fairly on the way. It has been found that this is im- 

 posing a task upon the plant which is altogether un- 

 necessarv. 



It was claimed that unless dendrobiums were kept cool 

 and dry in winter the flower buds would not de- 

 velop. Eipening of the pseudo-bulb is necessary but 

 sufficient light can be given for the purpose and the 

 proper percentage of moisture maintained to prevent 

 shrivelling without injury to the flowers. Atmospheric 

 moisture is of far greater importance than temperature, 

 especially during the American winter, when a large 

 amount of fire heat is necessary. 



North Boston, Mass. 



Pruning Ornamentals 



In pruning ornamental shrubs there are only two or 

 three things to bear in mind. First, the time of prun- 

 ing depends on the wood upon which the flowers are 

 borne. Most early bloomers have their buds well de- 

 veloped before winter sets in and so when they blossom 

 in the spring the flowers are carried upon the mature 

 wood of a year or more's growth. Therefore if this 

 class of plants is pruned in the winter it will mean a 

 sacrifice of all or at least a large part of the bloom for 

 the ensuing year. The only way is to postpone pruning 

 until after blossoming. 



But the shrubs that bear their flowers on the new 

 wood formed the same year, summer or fall flowering 

 plants as a rule, can be pruned at any time during the 

 winter with no danger of destroying the crop. 



The aim of pruning is to supply young, healthy, vig- 

 orous bearing shoots in abundance, and to develop a 

 beautiful shrub. To accomplish this the old and dead 

 wood is cut out, and that which is left if it tends to 

 grow rankly is slightly shortened in to introduce a 

 bushy habit of growth. Study the natural habit of the 

 plant and aim to follow it as far as possible. Above 

 all do not shear it off evenly all around into cone 

 shapes, round tops, or other symmetrical forms, unless 

 it is part of the landscape scheme. 



A rightly pruned shrub requires little attention; 

 shortening in the new wood, summer pinching of ex- 

 cessive growths, and thinning the centre is practically 

 the whole story. 



After winter is over, but before the buds swell; the 

 rose bushes must be attended to. Cut back strong 

 shoots less than weak ones, for severe pruning invigor- 

 ates and this will give the less progressive a chance to 

 catch up. All must be cut back to five or six buds, the 

 dead wood removed, and the head kept open. 



In the case of trees pruning is much more important 

 than it is usually credited with. While May is the best 

 month for this work, any time after the leaves are out 

 will do. This is better than winter pruning as the 

 wounds heal Over much more quickly. 



Young trees need to be trained from the start. When 

 first set out they should be cut back to nine or ten feet 

 for a tree with a two and one-half inch trunk. Espe- 

 cially is this true of the elm, maple, oak, and loose ir- 

 regular headed trees in general. It does not apply to 

 firs and the like, whose chief beauty is in their 

 sturdy uprightness. Take the maple for example. To 

 get a round symmetrical head it is necessary to keep 

 the leader cut back. This induces the branches to 

 strive for that position and as they get the nourishment 

 formerly going to the leader the tree gradually assumes 

 a handsome oval shape, instead of the long, lank, un- 

 gainly appearance it would otherwise have had, a sight 



