The management of forcing-houses in winter and spring has been treated of so often and so well by several correspondents of ' The Gardener,' that it would be difficult to write much that is new upon the subject, viewing the matter merely from a practical standpoint. I think, however, that the summer management of forcing-houses is somewhat overlooked, from the fact of the assistance rendered by the natural agencies of warmth and light. These agencies are not under-esticnated by us: on the contrary, we recognise their fullest value in forcing at all seasons; but there should be practical co-operation working along with these influences in due season.

We have heard it remarked before now that there is a good deal of repetition in the writings of the present day upon practical horticultural subjects. We think it is well that this should be so, as long as the matter is of a sound and practical nature, and will bear analysing. It is good for amateurs; it is good for those who are enlarging their horticultural sphere by plodding steps, and who gather much information from the practical writings of experienced cultivators; and it is especially good for young men for whom the horticultural press has done so much, and is likely to do a good deal more. It cannot, we think, be denied that the migrations of young men, and of some older hands too, is beneficial in so far as the opportunity, if properly used, may be turned to good account in acquiring experience in the conduct of every work. We find forcing-houses arranged on different principies, from the old-fashioned style of forty years ago down to the most modern ideas of the present day; and he who desires to add to his store of knowledge, may fairly exercise what resources he possesses in discriminating between principles which are the converse the one to the other.

.Now, if we begin with the most common of everyday operations - viz., that of giving air - we find room for exercising intelligence of the first order. There may be those houses so constructed that if air be not given in good time to dry up all condensed moisture from the leaves of Vines and Peach-trees, scorching is sure to ensue, or the tissues of the leaves may be crippled so that they do not perform their natural functions. It is simple to avoid this if the trees are kept in a healthy condition at the root. There is then little or no necessity for so much syringing to keep folioge clean.

Houses that lack the means of giving abundance of air require, in fact, special treatment of their own. They require a well-drained healthy border, in the first place; and secondly, they require a careful system of atmospheric treatment, and a practised stoker who has judgment to anticipate the weather and control his heating power with an experienced hand. The shutting-up and syringing of these houses with the same amount of atmospheric moisture, and at the same time, as houses of modern capacity - where plants are exposed to abundance of healthy air during the greater part of the day, - is as mischievous a practice as can well be imagined. In the case of Vines, the young growths will in a few days become extended and elongated beyond their normal length, causing confusion in training, and the bunches to become loose and straggling. The right course to adopt would be to keep the roots abundantly supplied with water, to give air early in the morning - say by 6.30 or 7 a.m. - and to sprinkle neither borders nor paths at any time except with full ventilation on in fine weather, and keep on top air till late in the evening. It is surprising how soon a difference in the growth and foliage of Vines will be perceptible under the latter course of treatment.

The leaves become large and leathery, the shoots short-jointed, and the bunches compact and shapely. How much longer will it be before this barbarous practice of bathing Vines is entirely dispensed with?

In the case of Peach-trees - much as has been written upon the subject, we still find cases similar to that of the Vines above referred to, and the conditions that apply to the one case will apply also to the other. We find work falling into arrears in the way of disbudding, thinning, etc, to be a gross sacrifice and waste of the trees - resources which should be otherwise directed. We also find, in the case of tying, in shoots (and here our young readers should be attentive), that where two or three are tied up together in a mass, to the exclusion of air and light, the result is unripe wood, feeble growth, flowers with badly-developed organs, and consequently defective fruits, which are not up to the mark in size or quality.

It should, perhaps, be observed here, that in the case of Peach growth the shoots can be as readily arranged and the vigour concentrated into any given number of shoots, as in the case of the Vine; whilst the converse result may be produced by pinching, which diverts the flow of sap into two or more channels, instead of one. Aim at a moderate and regular degree of growth of a size that will bear triplet buds, and let the foliage be of a dark, glossy green, and leathery to the feel.

In later houses which are being pushed forward or retarded according to circumstances, examine the borders down to the drainage by using a long narrow scoop, by which the condition of the soil may be tested, and if the latter is anything like dry,water carefully on two or three different occasions until the soil is thoroughly moistened. This is a much better plan than that of submerging a border that has been kept at the extreme of dryness for some time before. It enables the roots to recruit themselves gradually, and to resume their active condition of providing for the stems and leaves in a natural manner. It is also the first remedy (as dryness is the first cause) for red-spider, and is a more feasible plan of getting rid of the pest than by dashing the young leaves to shreds with cold water from a garden engine.

With regard to forcing pits, where Melons, Cucumbers, Strawberries, Beans, etc, are forced in quantity, the watering of the plants at the root, and the atmospheric conditions that are maintained, will either tend to promote good health and cleanliness, or it may have the contrary effect if the supply be not nicely gauged according to the respective requirements of the plants, their locality, and stage of growth. Melons will bear any amount of sun if they are grown hard and stubby, and may be watered as freely as Cucumbers in bright weather. The surface of the soil should also be mulched with cow or horse manure to encourage surface roots, and to save watering, which requires to be done more frequently when the soil is exposed to constant evaporation.

Cucumbers that are grown in houses through the summer, if the plants are to be kept healthy, should have a moderate degree of shade, and be trained fully 18 inches from the glass. All superfluous fruits should be removed before they draw unnecessarily on the resources of the plants. We prefer, however, to grow Cucumbers in low pits or frames through the summer, or from about June to September.

Strawberries in pots should always be watered between 9 and 10 a.m. every morning, and looked over again in the afternoon, if cleanliness is to be a certainty. Beans in pots and planted out should also be supplied with water at a uniform temperature - that is to say, if the Beans are planted out in a pit. With bottom-heat, do not give them water from 20° to 30° lower than the soil they are growing in. We know that we expect the weather to grow warmer daily, but a few hours or days of sunshine will not have the same effect in increasing the temperature of water two or three feet beneath the surface of the earth, that it will have in raising the temperature of the air in glass structures, or even upon plants that are growing upon the surface of the earth outside. It is therefore advisable to have all tanks filled with water in the morning (where there is not a supply in the houses inside), so that it will be exposed to the softening influence of air and heat before it is used for plants that are grown under glass.

It is by giving attention to minor details, and by assisting nature, that we succeed with summer crops; and still more so, that we succeed in producing fertility in fruit trees and other plants that are to be forced out of season. Cultivator.