It becomes a question, once the general plan is made, of establishing unity of details, of eliminating obtrusive, discordant, or redundant elements, of changing existing conditions by planting, grading, and otherwise establishing harmonious relations between the old parts and new parts of the place, for it is quite as important to carefully retain the valuable old part as to add new effects however charming. There is a superior quality peculiar to an old tree or the old and natural swell of the ground that should have the most careful attention, often to the extent of leaving it entirely alone and doing new work elsewhere where there is less to harm. It is one of the most difficult problems of landscape gardening to manage this combination of the old with the new in accordance with a good general plan so that you can feel yourself in the presence of genuine nature. The result we should seek to avoid is a gathering together in woodland masses trees and shrubs incongruous with their surroundings and therefore unnatural in appearance, and altogether unfitted to the general artistic scheme. To lay out a park or garden properly it should be studied on the ground and the peculiarities of the place carefully estimated and recorded so as to give due regard to comfort and convenience as well as artistic possibilities. The idiosyncrasies and even the less eculiar likings of the owner should also be considered and constant effort put forth to make a home that is a realization of his taste and requirements.
"How is it possible that any persons can make a ood design for any garden whose situation they never saw. To draw a beautiful regular draught is not to the purpose, for although it makes a handsome figure on the paper, yet it has quite a different effect when executed on the ground."
There should be also full realization of the fact that the work of laying out a park or estate, large or small, should always be considered more or less experimental. Plans of ornamental grounds have much less value than plans of architectural structures because changes are more likely to be necessary with live trees and shrubs than with wood and iron and stone. No landscape work is likely to be well done unless it has been changed from time to time. The study of the place should be continuous and kept up long after the initial work is finished. Sometimes a radical mistake is discovered when the landscape gardening is well advanced, but none the less should the mistake be remedied at the time, because the remedy is often difficult and expensive to apply and therefore likely to be left unapplied in after years.