In our uncertain climate, it not unfrequently happens that we receive an invoice of trees in the midst of a severe storm of cold, when the ground is frozen hard, and we have reason to suppose that the roots in the cases are frozen. This need not discourage nor alarm us, if the packing be good, for we have only to be patient and allow them time to thaw out thoroughly in the dark, and we shall find our trees all right. The packages should be placed at once in a dark cellar, and allowed to thaw gradually--if no such convenience be at hand, the boxes may be buried in the soil, or covered heavily with straw or hay, materials which are generally abundant in a prairie country, where commodious cellar room is not always at command. HEELING-IN, as it is called, is a very important operation to be performed so soon as possible after the receipt of the trees. It consists in placing the fibrous roots in immediate and close contact with the fresh and mellow soil, at some point convenient to the future planting. A ditch is dug with the spade, or a deep furrow is opened with the plow, in a sheltered, but elevated and dry situation, and in light mellow soil; into this the trees are placed as fast as they are removed from the packages, each kind being separated from the next by a distinct marking stick, and it is well to place the labeled tree first, as taken from bundles when untied. The trees are inclined at an angle, generally leaning towards the south, so as to have the stems shaded by their own branches. They are carefully placed separately and held in this position by one person, while the fine mellow earth is thrown upon the roots by another, who should take great care to see that all the interstices are filled with soil, so as to exclude the air from the fibres. This is especially necessary where the trees are to remain in this situation during the winter, when they will be alternately frozen and thawed. To secure them from injury, the earth should be banked up against them several inches; and it is well also to cover this with a heavy coating of leaves or some other mulching material, if it can be safely used without danger of attracting the field mice, which might ruin the trees. It is well at once to make a record of the trees as they stand, so soon as they are heeled-in, beginning at one end of the ditches or rows, and pursuing a definite order. This record will prove of great value, and very convenient in selecting the different kinds at the time of planting, and will enable us to restore the names in case of accidental loss of labels during the winter. The heeling-in of trees as they are received is recommended, even if everything is ready for immediate planting, unless the number be very small; but if the weather and our convenience permit us to place them at once in their permanent stations, the trees need not be heeled-in with so much care as when they are to remain for a longer period.