Mr. Editor, - One of the greatest secrets in gardening is, to do the right thing at the right time. And it is because they now require attention, that 1 send you at this season some remarks upon the cultivation of a class of plants which have of late years taken an enormous stride in the estimation of our floricultural friends of the old world. And most deservedly so; for they may be (and are there)' made to decorate the plant-houses for more than two months in the winter season, when flowers are by many the most valued.

Those who have only seen Chrysanthemums as they are grown out of doors, can form no more idea of their beauty, with proper culture, as pot plants, under glass, than one could obtain of a Newtown Pippin from a crab-apple. The bloom of the large varieties may be grown four or five inches in diameter, and many of them are of most exquisite form. As to color, they may be had of almost any shade that is desired, except perfect blue or black.

The large varieties, when well grown, are undoubtedly the most beautiful. But the pompone or dwarf sorts, which are of comparatively recent introduction, are with many persons the greatest favorites, from the circumstance of their more compact growth, and their not taking up so much room.

There are many ways in which this family of plants may be grown with a satisfactory result, some involving more care and expense than others, the best of which 1 will describe.

The first thing is propagation; and March and April are the best months to begin, if very large specimens are desired; but May and June are early enough to obtain good handsome plants before the blooming time in November.

Take, then, suckers from last year's plants, which in March and April will make their appearance above the surface of the soil, and put each in a three or four-inch pot; or they may be planted out in a garden frame, or under a glass hand light, a few inches apart. They will probably have some roots when taken from the old plant; but whether or not, they will soon strike root, without the aid- of artificial heat In three or four weeks, when the point of each is seen to grow, cut or pinch off the top, at three or four inches above the surface of the soil. In a few days, a shoot will be observed to come out from the axil of most, if not all the leaves, below where the plants were cut or "stopped," as it is termed by gardeners. As soon as these shoots are distinctly seen, (but not before,) place the plants at once in the pots in which they are to bloom. The size of these pots may depend on the use to which they are to be applied when in bloom, such as decorating rooms, etc.; but to grow them in the greatest perfection, the large or tall growing varieties require a pot eleven inches in diameter, and the pompone, one seven or eight.

The compost in which to grow them is the next point. Two thirds good loam and one third well decayed manure, mixed together, and used in the rough state, without being sifted will suit them admirably. More manure would encourage leaf development too much. <

Place one plant in the center of each pot; and when potted, keep them in a garden frame until night frosts are over. Immediately after that .place them out of. doors, in an open situation; but plunge the pots, or cover them with sawdust, hay, or some material to keep the sun from the sides of the pots. Place the pots three feet apart'every way; the plants must have ample room to grow, and as they are to remain in the same situation until just in bloom, it saves trouble to give them room enough at first. Cinders or boards, to keep out worms, should be under the pots; and the pots should be lifted up once a week or ten days, to prevent the plants from rooting down into the ground, unless boards are underneath.

Water must be liberally supplied, morning and evening, to the plants, in dry weather, both to the pots, and through a rose or syringe overhead. They should never be allowed to flag for want of water; but if they should happen to be neglected, a good watering will restore them to health and vigor; although, if that happens often, they certainly suffer materially.

As soon as the shoots that were seen to be growing when potted are three or four inches long, they should again be stopped, or have the point pinched off from each shoot. This stopping should take place not later than the end of July; and after this they will not require any more stopping or cutting, but the shoots that will thenceforth be made will all remain to bloom.

As these shoots grow, they should be tied out and spread, so as to admit air freely to all parts of the plant. This process requires attention from time to time.

About the middle of August, and from that time forward while the bloom buds are forming and growing, manure water may be given to the plants every third day with advantage. This may be made by stirring up a couple of spadefuls of old manure in five or six gallons of water, and letting it stand until clear.

Towards the middle of October, the buds will appear in large clusters. To have fine bloom, these should be thinned, leaving only one bud on each shoot. Their size is by this means much increased; and from the number of shoots the display of bloom will be magnificent.

As soon as there are symptoms of approaching frost at night, the plants should be removed to a greenhouse, or to an empty room without fire, so that the bloom may expand gradually; keeping the plants, if in a room, as near as possible to the window, that they may have all the light possible. Watering must be attended to, but not over the foliage after the buds begin to expand.

Supposing the plants to have been raised from cuttings late in May or in June, the course of cultivation will be the same, except that they must not be stopped more than once, (about the middle or end of July,) and of course they will not be such large plants, and will not require such large pots.

The above is perhaps the best method of growth for general purposes; but assuming the amateur to be an enthusiastic florist, anxious to show the extent of his skill, very much larger blooms may be obtained of the tall growing varieties, to exhibit as cut flowers, by a system that I will now explain. But the plants themselves will not exhibit that luxuriance of habit, clothed with foliage when in bloom down to the pot, as they will by the way above detailed; that is, provided they have been well attended to, as to the supply of water; for if at any time that has been allowed to fail, the lower part of the foliage is sure to fall, or rather wither.

To grow the lergest size blooms, take suckers in April, and plant four in a four or five-inch pot, place them in a frame or under a hand glass, and shade the first week if the sun is strong. As soon as the pot is full of roots, in a month or so, transplant without breaking the ball, and without stopping the plants, into an eleven-inch pot. Treat the plants exactly as before directed, except that they are to be allowed to run up as tall as they please; but pinch off all laterals or side shoots, leaving nothing but the main stem and the leaves upon it.

When the time arrives for the formation of flower buds, pinch off the first bud that appears, and then the top of the stem will divide into three heads, with several buds on each. Take off all the buds but one on each division, leaving, therefore, three buds on each plant; and as there were four plants originally to each pot, that will give twelve blooms. Provided due attention be given to watering, and that manure water is given, as above directed, after July, but not earlier, these twelve blooms will look more like Dahlias than like ordinary Chrysanthemums.

On this system, suckers will sometimes come up in the pot before the bloom is expanded; if so, take them out by cutting them at or just below the surface of the soil, so as to keep all the energies of the plants concentrated in the growing buds.

There is another mode by which good bloom in pots may be obtained, with much less trouble. But with true florists, "trouble " is a word not known to their dictionary!

If the plants, when propagated in spring, are planted out in a piece of good garden ground, three feet apart, and then stopped once, at the end of June or in July, and are duly supplied with water, they may be removed into pots in September, being carefully taken up, with good balls of earth. They should immediately be placed in the shade, out of doors, and kept there a week or ten days, well watered daily. After that, place them where they can get the morning or the afternoon sun for two or three hours; and when frost threatens, take them in-doors to bloom. In this way, even, they will afford much satisfaction.

After bloom is over, cut down the stems, and keep the pots through winter, (without water,) in a dry cellar or barn, cool, but free from frost, nearly if not quite. Many sorts will live in the open ground all winter; but V>me will not usually. In March, look to them, and give water, or shake out the ball of earth and commence the year's propagation.

[We will just add, that it is worth all the trouble to raise the Chrysanthemum in the manner so clearly described by Amateur. - Ed].