GREENHOUSE 



400 



GREENHOUSE 



the ventilation of the different compartments. Slight 

 wooden movable divisions we find extremely useful with 

 plants in pots, as we can then give a peculiar treatment 

 to one or any number of lights at pleasure. 



Firing. The heat from the furnace merely extends 

 vegetable tissues ; that from the sun expands and con- 

 centrates them. No stoker should visit his furnace 

 without knowing the temperature of his house, the 

 temperature of the external atmosphere, the direction of 

 the wind, and the changes that have taken place in a 

 certain number of hours, and thence calculate what will 

 be the most likely to happen. The minimum tempera- 

 ture should never be exceeded by fire-heat during the 

 night. More than sufficient is not only waste, the plants 

 are drawn and dried, while less advantage can be taken 

 of the glorious light and heat which come from the sun. 

 For dispersing damps, &c., use a brisk little fire during 

 the day, and allow it to go out. In very dull, close 

 weather in winter, such a fire often, if even for an hour, 

 would be useful ; not for heat, but for enabling us to 

 give more air, and causing a rapid circulation among 

 the plants. 



Watering. The rule is, water so as to reach every 

 fibre of the plant's roots, and then wait until a similar 

 repetition is necessary. A plant may want watering 

 twice a day in summer, and, perhaps, only twice a month 

 in dull weather in winter. From the end of September 

 to the middle of May, let the temperature of the water 

 used be from 5 to 10 higher than the minimum tempera- 

 ture of the house. From the periods mentioned, making, 

 of course, due allowance for peculiar weather, watering 

 should be performed in the morning ; in cold weather 

 not too early. Thus the stimulus of sun-heat, diminished 

 though it be, meets the plants when they have received 

 their refresher ; the extra moisture is parted with before 

 the evening comes ; and there is not that rapid cooling 

 of the soil by evaporation during the night. In the 

 summer we reverse the time of watering, and perform 

 the operation in the afternoon and evening. Anything 

 that tends to cool the soil and the plant is then refreshing. 

 By watering in a bright morning, the moisture is exhaled 

 rapidly from the soil, as well as through the foliage of 

 the plant, which does not, in consequence, receive the 

 full benefit of the watering, and, therefore, soon requires 

 a fresh supply. In the evening the evaporating ten- 

 dencies are approaching the minimum ; the plant has 

 full time to absorb and refresh itself, and thus is more 

 able to stand the brunt of the following day. 



Manure Watering. This should be applied often, but 

 weak and clear ; a little quicklime added will effect the 

 clearing, at the expense of driving off a portion of the 

 ammonia. It is applicable in almost any case where 

 luxuriance of plant is the chief object ; where size of 

 bloom and compact, rather than slender, growth, are 

 the desideratum, it should not be applied until the 

 flower-buds appear. 



Syringing. This is a most valuable mode of applying 

 water, as it promotes cleanliness, and is as necessary for 

 removing dust and incrustations from the foliage as 

 soap and water are for cleaning our own skins. In 

 winter it should be done at midday, when the sun shines ; 

 in spring and autumn, in the morning ; in summer, 

 chiefly in the evening, though at that season we frequently 

 give them a dash several times a day. 



Pruning. This is generally done when the plant has 

 finished flowering when we wish it to start into fresh 

 growth. Of course there are exceptions ; without these 

 exceptions the nature of a plant and the mode of its 

 growth must be the basis for a system of pruning. For 

 instance, we cut down the flowering shoots of an Epacris 

 and a Pelargonium ; but we act very differently both 

 before and after in the two cases. The Epacris is hard- 

 wooded, and, if tolerably ripened, it requires no pre- 

 paration. The long branches of most kinds are cut in 

 at once, and the plant is then transferred to a closer 

 and warmer atmosphere, to encourage the formation of 

 new shoots. A cold pit, kept close, is the thing ; some 

 people, with great success, keep them a couple of months 

 in a plant stove. Of course they are duly hardened, 

 and the wood ripened by autumn. On the other hand, 

 the stems of the Geranium are soft and spongy ; if a 

 very valuable kind, this will have been increased by 

 shading, to preserve the colour of the flower. The plant 

 altogether is at a minimum as respects its possession of 

 organisable material ; while, for the sake of the old plant 



to be kept, and the cuttings for seed from its stems, it 

 is desirable it should be at the maximum. The plants 

 are therefore exposed fully to the sun ; not a drop 

 more water is given than just to keep the leaves from 

 flagging ; and the stems, instead of being soft and green, 

 become hard and brown, by parting with their watery 

 evaporations, and assimilating fresh solid material. 

 Many other close-headed plants, such as the Azalea, 

 merely require, in general, the stopping of a few of the 

 strongest shoots. 



Time of Potting. This should generally be done after 

 pruning, and when fresh growth has taken place, because 

 it is advisable never to give more checks to a plant at 

 once than can be avoided. When cut down, or pruned, 

 the energies in the stems, and the unmutilated, untouched 

 roots, are at once put forth in the production of fresh 

 shoots. When these are formed and forming, and the 

 plant is kept close for a time after shifting, fresh roots 

 will soon be formed through their agency, upon the same 

 principle that roots are protruded from a cutting of half- 

 ripened wood under a hand-glass. 



Time for Cuttings. Now we speak merely in general 

 terms. Other things being equal, the older and harder 

 the wood of the cutting, the longer will it be in striking. 

 The younger the wood is, provided it is just hard enough 

 at the base to possess a sufficiency of organisable material, 

 the sooner it will strike ; if too soft and spongy it will 

 rot and damp off. Hence the general time for propagating 

 is regulated by the general time of pruning and fresh 

 growth taking place. Small side-shoots, from ij to 

 3 inches in length, just getting firm at the base, cut to 

 a point with a clean, sharp knife, or taken off close to the 

 older branch, and a few of the lower leaves removed, 

 will succeed in the great majority of cases. It is desirable 

 to get them in in April or May, in the case of slow-growing 

 plants, to have them established before winter. We shall 

 merely add a few requisites : (i) clean pots ; (2) secure 

 drainage by an inverted small pot inside a larger one, 

 or by crocks, so as to fill it three-quarters full ; (3) place 

 rough material or moss over the drainage, to prevent 

 the finer soil washing through it ; (4) cover it with an 

 inch or so of sandy soil, similar to what the plants 

 delight in, if a little charcoal is added all the better, 

 finishing with a layer of pure sand, watering all well, and 

 then allowing it to drain before inserting the cuttings ; 

 (5) insert the cuttings firmly, fill the small holes made 

 by the dibber with sand, dew all over with the fine rose 

 of a watering-pot, allow the foliage to become dry, place 

 each pot under a bell-glass, or a number under a hand- 

 light, and shade from the sun, either in a corner of the 

 greenhouse, or, better still, in a close frame or pit without 

 any artificial heat being applied, at least none before 

 the cutting begins to swell at its base. Some things 

 may have bottom-heat at once, especially those that 

 have been a little forced previously. Though shade be 

 indispensable, yet as much light as the cuttings will 

 endure must be given, increasing the quantity gradually. 



Sowing Seeds. This may be done at any time when the 

 seeds are thoroughly ripe. As it is of importance to 

 have the seedlings potted off and established before 

 winter, April and May are the best periods in several 

 circumstances. Where there is no hotbed the latter 

 period will be the best, and even then, for confining 

 heat and moisture, the pot should be covered with a 

 bell-glass, or a square of glass laid over it. Where there 

 is a hotbed, such as a cucumber frame, the seeds may be 

 sown a month or six weeks earlier, and hardened off as 

 soon as they are fairly up and potted off. In sowing, any 

 light, sandy soil will do ; for all fine hairy-rooted plants 

 sandy peat is the best. The pots should be nearly as 

 well drained as for cuttings, watered, and allowed to 

 drain before sowing, as the less water they have after- 

 wards until they are up the better. Hard seeds that 

 have been kept dry over the winter will vegetate all the 

 sooner for being steeped several hours in warm water, 

 say from 13 to 14. In covering the seeds the thickness 

 should be regulated by the size of the seeds. Hence, 

 for very small dusty seeds, the surface of the fine soil 

 should be made smooth, the seeds evenly scattered over 

 it and slightly pressed in, and then just dusted with a 

 little fine sand ; but in unpractised hands it is safer to 

 be content with the slight pressing in with a clean, 

 round board, having a nail in the centre to hold by, 

 and then place a square of glass over the pot, with moss 

 or paper above, to shade until vegetation has taken place. 



