WOODY PLANTS FOR NEW ENGLAND 69 



used for very small hedges in warmer sections, but elsewhere considered to be 

 a rock-garden plant. 



Thuja occidentalis AMERICAN ARBORVITAE 



A familiar native evergreen which has worked its way down from extreme 

 northeastern North America. Usually at its best on non-acid soils. Like all 

 other much-cultivated plants, it has been sorted out in gardens into numerous 

 varieties or clons. Though greater uniformity may be had by use of material 

 propagated from a single desirable parent plant, seedling variation is not so 

 great as to preclude the use of seedling plants for tall screens or clipped hedges 

 on areas having a fertile, well-drained soil. Except for a lack of luster during 

 the winter months, the type Arborvitae stands next to the Yew and the Hem- 

 lock as material for evergreen hedge making. Such use demands a type of 

 pruning which will permit the light to strike at the bases and thus prevent 

 destructive shading of the lower branches. The present trend is away from 

 the use of globe-shaped forms which in the past were, in small sizes, much 

 favored for filling up suburban plantings. Var. COLUMNARIS differs from 

 the type in being leafier and in having a columnar rather than pyramidal habit. 

 It retains better color in winter, transplants more easily than the type, and 

 makes a dense hedge much more quickly than var. fastigiata. Var. douglasii 

 pyramidalis (T. occ. spiralis) is a dark, dense, narrow pyramidal form of 

 interest while young because of the crested appearance of its branchlets and 

 good winter color. Var. FASTIGIATA (T. occ. pyramidalis), Pyramidal 

 American Arborvitae, is a form with about the same leaf-color as the type, 

 and is much used in formal planting because of its narrow pyramidal habit 

 and ability to retain a pleasant green color during the winter. When used as 

 a hedge plant, an interval of some years may need to elapse before the lateral 

 branches meet to form a close screen. Var. nigra is a garden form sometimes 

 offered in New England, which improves on the type by carrying a darker 

 summer coloration and not becoming as brown in winter. Var. ROBUSTA 

 (T. occ. Wareana), Ware Arborvitae (Siberian Arborvitae), is a dense, 

 slow-growing, broad-based variety with rather rugged-appearing foliage which 

 carries a pleasant bluish-green color through all seasons. It is easily adapta- 

 ble with a minimum of pruning, for making medium-sized evergreen hedges. 

 Var. ROSENTHALII, Rosenthal Arborvitae, is a broad-based, pyrami- 

 dal form, valuable because of fine-textured, dark foliage and compact growth. 

 Var. Wagneri is a plant of slow growth, egg-shaped habit, and deep gray-green 

 foliage. 



THYMUS SERPYLLUM Mother-of-Thyme 



Here are included a host of botanical and garden forms of prostrate Thymes 

 so useful for planting on banks, in rock gardens, in paths, and for other uses. 

 Numerous forms based on variations of flower color, leaf color, or other prop- 

 erties are available. 



TILIA Linden 



Lindens are, with us, for the most part, a mixed population of seedling plants. 

 There is need for wider use of the practice of vegetative propagation from 

 properly identified and carefully selected parent plants, in order that uniform 

 stocks may be made available. Listed here are some, but not all, of the worth- 

 while species and clons. In addition to their suitability for use as large trees, 

 the fragrance of their interesting, though inconspicuous, June or July flowers 

 is a property worth consideration. 



