In consequence of this mode of management, and the limited space which there necessarily is between the plants, some species will soon grow so large as to intermingle their branches, or their suckers, with those which are adjoining them. Whenever this is the case, the overgrown plants must not be thinned or pruned, but be entirely taken up by the roots, the soil stirred up to the depth of 2 or 3 feet, some fresh soil added, and a young plant procured from the nursery of the same kind as that taken up, and planted in its place, on the summit of a circular hill of earth of the same diameter and height as at first: that is, as before stated, on a hillock of from 3 ft. to 5 ft. in diameter, and from 1 ft. to 1.5 ft. high in the centre, above the adjoining surface. The brick tally is then to be replaced on a foundation of bricks, so as not to be buried above 1 in. by the soil, as at first planting the Arboretum. Some of the poplars and elms may require to be taken up and renewed in this manner in the course of 15 or 20 years; and perhaps some of the shrubs which throw up numerous suckers, such as the common lilac and common philadelphus, and some which throw out rambling shoots, as the common bramble, may require the same treatment at the end of the same period, or before. Whenever any of the branches or suckers extend so far as to cover or partially obscure the brick tally, it and its foundation of bricks must be taken up and removed 1 or 2 feet further from the plant; and whenever the glass of any tally is broken, or the card with the name becomes dim, or any other accident happens to it, it must be repaired or renewed by the curator from the reserve stock of bricks, printed cards, and pieces of glass, kept in the north lodge and the flower-garden cottage. The miscellaneous collection of roses in the surrounding belt will require particular attention to prevent them from being injured by the adjoining evergreens; and, as roses are short-lived plants, some few of them may, perhaps, die every year. Whenever this is the case, the root of the dead plant must be taken up, the soil thoroughly stirred, some fresh soil and manure added, and a new plant, of the same kind as before, inserted. When a new plant of the same kind cannot be procured, some other kind of rose of the same section, and not already in the collection, must be planted, and a new name tally prepared accordingly.
