The fine cedars which adorn the immediate environs of the house were (with the exception of two, raised from a cone brought immediately from Lebanon, by the celebrated Oriental traveller, Dr. Pococke) all raised from seeds by the first Earl of Caernarvon; and the largest of them was planted out between the years 1773 and 1778. These fine trees may serve to dissipate a commonly prevalent error, which attributes to the cedar of Lebanon the character of slowness of growth; and to show planters that this most stately of evergreen trees actually makes a progress superior to most trees in our climate. A fine specimen, upon the lawn opposite to the northwestern angle of Highclere House, was planted there in the spring of 1778, being then 4 ft. high, and having been raised from a cone gathered at Wilton in 1772. Being measured on the 5th July, 1832, its circumference, at 3 ft. from the ground, was 10 ft. 2.5 in.; another, immediately to the south of it, being examined at the same time, measured 10 ft. 3 in.; a third, in the park to the north of the house, and close to the back entrance, measured 10 ft. 6 in.: but it is useless to multiply instances. Beeches planted about the same time are not nearly so large.
The first Lord Caernarvon, who not only thus improved his grounds, but also added largely to his mansion, and gave it a third front to the north, died in 1812. His plans were actively pursued by the late earl; who, bringing to the task taste of the highest order, added most materially to the magnificence of his demesne. A large extension of Milford Water, not yet completed according to his views; the creation of the exotic plantations surrounding it; a new line of approach to the house, the alteration and improvement of which occupied much of his attention during the latter years of his life, and were left incomplete; and the creation of the curious collection of American plants scattered through the shubberies in the pleasure-grounds, are among the operations of the late Lord Caernarvon. We have spoken of the magnificent cedars which adorn the lawn at Highclere. The heath-mould plants, usually denominated American, are not less striking. Unfavourable circumstances of local climate, which hardly allow an arbutus to protract a wretched existence, induced His Lordship to rely principally upon rhododendrons and azaleas for the decoration of his shrubberies. To extend the garden varieties, and protract the flowering season of the family, became an object which, most actively pursued, has been attended with uncommon success. By means of hybrid intermixture, the season for these beautiful flowers, beginning about the end of April, lasts till the middle of July, almost three months. The very splendid rhododendrons, brilliant to the highest degree with their crimson corollas, of the variety obtained between the Rhododendron arboreum of Nepal and R. catawbiense, and named, by Dr. Lindley, after the Doomsday name of Highclere (Alta-Clera), Rhododendron alta-clerense [see Bot. Reg., vol. iv. t. 1414., and VII. 472. (In this page, Mr. Gowen, the originator of all these hybrids, is spoken of as the gardener at Highclere. This is erroneous; Mr. Gowen should have been designated an amateur of gardening; Mr. Carton was the gardener at the time the first hybrid rhododendrons were raised, and one variety (see Hort. Brit. 29193.) is named after him.)], come into flower about the third week in April, and are succeeded by a multitude of splendid varieties both of Rhododendron and Azalea, ending with the crosses obtained between Rhododendron maximum and Azalea autumnalis rubra. The number is continually increasing; and, however perplexing to the botanist, who will have the disagreeable task of distinguishing between indigenous species and these endless horticultural varieties, yet it must be owned that to this art of hybridising the flower-garden is, and will be, indebted for a great accession of beauty and enjoyment. Of the many achievements of this nature at Highclere, the most striking is to be found in the crosses effected between R. arboreum and the hardy species. These hybrids, which as far surpass the common rhododendrons as the new double Scotch roses do the old wild ones, are perfectly hardy, exceedingly floriferous, and cannot be surpassed in splendour. Of the azaleas, the most splendid are bred between the fine garden varieties of Azalea calendulacea and Azalea nudiflora var. rubescens; and it may be predicated of all these hybrids, that they possess a much greater tendency to profuse flowering than the unadulterated species. [Some account of the origination of these will be found in VII. 62.] The history of the hybrid R. alta-clerense is curious in the way of floricultural anecdote. To obtain it had been a great desideratum; but the specimens of R. arboreum at Highclere had shown no disposition to flower. The only places in England where it then (1826) flowered were Hylands (Mr. Labouchere's), and at the Grange. From the latter place an umbel was obtained and conveyed to Highclere in a tin case. By means of its pollen the flowers of R. ponticum and R. maximum were fecundated, and about 1800 seedlings were raised, many of which, after supplying his private friends, Lord Caernarvon desired might be distributed among the nurserymen. This was done in the spring of 1831. Those which were retained at Highclere have now attained a flowering age, and form extensive shrubberies round the house.