Dear Sir, - In the engraved plate of Strawberries which you present in your last number, the same error is renewed which has been heretofore committed, and by which even Mr. Downing was misled, describing under the name of McAvoy's Extra Red, a totally distinct variety named and sent out from Cincinnati as McAvoy's No. 1. The Extra Red proved to be the most sour and worthless of all Strawberries. It is an Hermaphrodite variety, with dark crimson berries. The McAvoy's No. 1, is a pistillate variety, with light scarlet berries, rather acid, but not so much so but that they are rendered palatable by sugaring. Having originally received these and the McAvoy's Superior and Long worth's Prolific direct from Mr. Longworth's garden, and a duplicate assortment from Mr. McAvoy, and a triplicate from another Cincinnati garden, they have always been cultivated in my garden with precise identity. I refer to the confusion of the two varieties more especially, because I have been twice assailed for my description of McAvoy's Extra Red, (once by Carew Saunders,) when the complainants were utterly ignorant of the actual facts, and were themselves misled by having McAvoy's No. 1, under an erroneous name.

While on the subject of Strawberries, I will cursorily refer to the much-mooted point, "the best period for transplanting them." After the numerous plantings we have made, we have attained to a settled conviction on this question. I am positive that the month of September is preferable before all other periods for the State of New York and the States to the north of it, and from the 20th September to the 1st November, for the States adjoining on the South as far as the Potomac; and the months of October and November for the more Southern States. The plants set at the periods named will become well established, and will usually form several runners before the winter sets in. They will consequently be well prepared to sustain themselves through the severe winter weather, and will produce a fair crop the ensuing season.

I am often amused to hear people express fears as to cultivating Strawberries successfully in our Northern States. Why so? I ask them. The Strawberry is found growing naturally further north than any other garden fruit. Hudson's Bay abounds with them. Richardson found vast fields of them in the Arctic region. The shores of Oregon and around Puget Sound produce fine Strawberries in great profusion. In point of fact there is not a garden in our most Northern States, and including the British Provinces, which can not be made to readily produce as fine Strawberries as we grow around New York.

Yours fraternally, Wm. R. Prince, Flushing, Sept. 16,1861.

[In regard to the Extra Red and McAvoy's No. 1, we know there has been some confusion. We got our plants of Mr. Longworth, who selected them very carefully when in fruit, and pronounced them to be genuine. We also received the same from Mr. McAvoy through Mr. Pardee. We append a description of both taken from our memorandum book for 1854, and should be glad to have Mr. Prince compare it with his own, and see how far it agrees with his:

McAvoy1 s Extra Red, Pistillate: foliage large; deep green; leaflets elongated; serratures medium; flowers small; petals 5, round.

McAvoy's No. 1, Pistillate: foliage large, deep green; leaflets roundish; serratures coarse; flowers medium size; petals 6, somewhat open.

It will be seen, that though we got our plants from the same source that Mr. Prince did, they are both pistillate. We have always supposed them to be true. If possible, we should like to have each identified. In regard to the fruit, No. 1 is less acid than the Extra Red. Mr. Longworth might throw the necessary light on the subject. Mr. Prince's experience and our own agree precisely in regard to the best time for planting the Strawberry; beds, indeed, may continue to be made around New York up to at least the middle of October, with the certainty of a moderate crop of fruit the next spring. It is astonishing how rapidly a newly planted Strawberry will root in the fall of the year. We think nobody need have any fears as to the successful cultivation of the Strawberry in our Northern States, and it is a fruit that all should have. - Ed].

Peter B. Mead, Esq.: Sir, - If you have ever been upon the highlands of the Delaware, in northeast Pennsylvania, you may have seen the Rhododendrons which grow there, often in large bodies, and reach the height of ten or fifteen feet They appear to flourish upon a thin sandy soil, resting upon a compact subsoil. They are beautiful, both in flower and foliage, having leaves seven inches long and perhaps two broad.

Is this the Rhododendron maximum, or the American Rosebay, or the Tree Laurel? Is there a more desirable, thoroughly hardy kind, suitable for a lawn of a half acre's extent?

I have a bed of Kalmia latifolia; the plants, which were old ones by the road side that had been cut down to the ground, and had sent up a new growth, stand two feet apart, and are about two feet high. Would not the intermediate spaces be well adapted to raising Rhododendrons from the seed?

In regard to Kalmias, my experience leads me to think that the rays of the sun must be always kept from the foliage by trees entirely overspreading them. The winter sun I think to be as injurious to them as the summer. But the branches of a large deciduous tree appear to temper sufficiently the sun's rays in that season. Those plants in my bed which are thus protected have now, for two years and a half, kept their foliage unshriveiled, and of a dark green color, while the others, immediately after they were transplanted, sent out a vigorous growth, with narrow and yellow leaves, and continue to do so.

It is an unfortunate necessity to be compelled to prepare shade for plants of this kind, and probably for Azaleas, Hollies, etc, but does not your own observa. tion confirm what I have said? I have heard it said that swamp muck, owing to the lime contained in it, is not good for plants of this class; others recommend it highly.

Is there any thing inadmissible in the root-pruning of the Grape-Vine? I have a border, fifty feet by six, containing four Isabella vines, planted eight years ago. The soil is a good gravelly loam, resting upon gravel, and was enriched, to the depth of two feet, with a large quantity of stable manure, and two barrels of poudrette and ground bones. Each vine has borne nearly every year, but only a few bunches, and those not very large, nor more than once or twice sufficiently ripe to have the true rich flavor of the Isabella. The growth is very rank, and they have been regularly fall pruned, though, perhaps, unskillfully. Last fall it was done by an experienced vine dresser, and the wood largely cut away, with a view to get in place of it a new stock of wood. This summer, considering the close fall pruning, and the winter killing which befell the vines, the number of bunches they show may be indicative of a perceptible increase in productiveness.

This summer I have, for the first time, kept the vines curtailed, confining them by pruning to the trellises, eight by eight, and the young laterals to one joint from the cane. But there is so much forcing power at the roots that the buds of the laterals are bursting, and I have the mortification of seeing my next year's crop somewhat lessened by the operation. Now, Mr. Editor, is there any other way than to root-prune in a case like this?

The trellises lean against a lattice screen, running parallel to a barn, and four feet from it, leaving a passage way which is roofed. The vines are planted two and a half feet from the lattice, the lattice seven and a half feet high. The trellises face 30° S. of W.; the vines have all the sun after ten o'clock. With these details, perhaps you may be able to suggest some cheap plan for a glass covering, if the vines can ever be made to bear abundantly. In this valley we can rarely have thoroughly ripe grapes, without brick walls or glass covering. The vines I should think, might remain uncovered from the 1st of June until the 1st of September; or would you suggest to destroy these vines and replace them with Concords or Delawares, or Peaches, to be trained and provided with some kind of screen for winter protection? I see I am making a long list of questions, and, perhaps, taxing your time. - Very respectfully, your obedient servant, Owego, Sept. 3, 1861. A Subscriber.

[We are much pleased with the manner in which you describe your difficulties; you make them interesting to others as well as yourself. The Rhododendron alluded to, we have no doubt, is the R. maximum. The space between your Kal-mias might be used for seedling Rhododendrons, but we should prefer making a bed for them, especially if the seed had been hybridized: success would be much more certain. If Kalmias are transplanted when quite young, they will bear considerable exposure, and keep their foliage thick and green; otherwise, your plan is best. They will always be more stocky if not smothered by limbs of trees. If planted on the east or southeast side of a clump of trees they will need no other protection. We esteem muck very good for this whole class of plants. Your Isabella vines have undoubtedly been over-stimulated. A little root pruning, and withholding manure for a year or two, would bring them into bearing condition again; but we would advise you to plant other kinds, with no other preparation than simply forking over the soil. Treat the Isabellas as suggested, but gradually replace them with Delawares, planted four feet apart in rows, the rows being about six feet apart. The Delaware will ripen with you. The Isabella is not worth the trouble of covering with glass.

It would be better to build a cheap grapery than take so much trouble with the Isabella. Try our suggestion, and begin this fall; you will hereafter thank us. The stopping of the top and laterals will inevitably cause the buds to break, when a vine is growing vigorously. Pinch the laterals to a leaf as soon as that leaf is as big as a dollar, but let the tops go. Our grape articles will explain all this before you reach another season. Please let us hear from you again, and tell us about the average of your spring and fall frosts, how late and how early. We will then tell you more about grapes, and something about peaches. - Ed].