Most woody plants have green leaves throughout the growing season, but some have different colored foliage in the early Spring, and because of this, they may be given special varietal names.
These colors may be pronounced – for a few weeks as the plants start into growth -but in many plants, these colors gradually give place to normal green as the foliage matures.
Many gardeners have been greatly disappointed by some of the Japanese maples. These are bought early in the Spring and their leaves first appear a brilliant red. But, as the foliage matures, the leaves gradually lose this color and take on a reddish green to green tint that remains for the rest of the season.
There are a few plants, on the other hand, with foliage that stays colored the entire growing season. These plants should be recognized for this trait and used if the gardener wants to create a specific effect with them.
Plants with colored foliage are very difficult to use properly in the garden. So often we see blue spruce or shrub with variegated leaves planted in such a conspicuous place in the garden that it detracts from all else. This is never to be recommended.
Also, it should be realized that many plants with variegated foliage and usually those with completely yellow leaves grow less vigorously than their green-leaved relatives, merely because they are deficient in chlorophyll, the green coloring matter so essential in the manufacture of food. Such plants need pampering to coax them into some semblance of normal growth.
If their shortcomings are recognized, and they are used with discretion in the planting plan, some can give desirable effects. Especially is this true in the shrub border where just a little variation in the omnipresent green may create just the right amount of interest. Many varieties of plants with variegated leaves are available from commercial nurseries, but others with a fairly uniform color, are much easier to use correctly.
Red Leaf Foliage
Shrubs with red leaves are exemplified by Acer palmatum atropurpureum, the blood-leaf Japanese maple. The true variety as it grows in the Arnold Arboretum has red leaves all Summer.
Some nurserymen grow Acer palmatum from seed, and select the red-leaved forms, giving them this name, but this practice results in many inferior forms. The variety mentioned is dependable and perfectly hardy in Boston.
The red-leaved form of the Japanese barberry, Berberis thunbergii atropurpurea, is another common type, with red foliage if it is grown in full sun. In a partially shaded place, this and several other plants will not color as much as they might.
The new barberry, Sheridan’s Red, at first was named a variety of the Japanese barberry but is not. It is susceptible to the black stem rust of wheat, hence it might be omitted from consideration.
Both the Myrobalan plum, Prunus cerasifera, and the Blireiana plum Prunus blireana, have several varieties, the foliage color of which is a dark purplish red. These are small trees, with small purplish flowers and fruits that do not amount to much, but the foliage is a uniform color throughout the growing season.
After all, they are plums, and susceptible to various plum ailments, but the prominent color of the foliage is what seems most desirable to many gardeners.
Much easier to grow, with less care, would be the purple smoke bush, Colinas coggygria purpurea, now hard to find in nurseries, but years ago a favorite in gardens. Not only is the foliage a constant purplish red, but also the fluffy fruit clusters from which it takes its common name.
Then there is the purple giant filbert, Corylus maxima purpurea, and the little purple-leaved weigela, in the trade as Weigela florida purpurea. This grows only about two feet tall in the Arboretum and has foliage more of a purple color than any of the others mentioned.
Yellow Leaf Foliage
Yellow-leaved plants are very difficult to use properly because they are so conspicuous. Ligustrum vicaryi, Lonicera japonica aureo-reticulata, and Cornus alba Rosenthal, all have bright yellow foliage if grown in the full sun, and greenish foliage if in the shade.
The yellow-leaved ninebark might be mentioned, for it is most colorful early in the season, up to the first of July, after which it fades perceptibly.
Gray Leaf Foliage
Plants with gray foliage are among the easiest to use and might be given first consideration. The little lavender is a popular inhabitant of many gardens, while the Russian olive, Elaeagnus Angustifolia, and the lead plant, Amorpha canescens, are standard shrubs of considerable merit. Especially true of the Russian olive, for the gray foliage and shredding bark give it interest the entire year even though the flowers and fruits are insignificant.
Other shrubs with gray foliage would include the sea buckthorn, Hippophae rhamnoides, the female plant which bears brilliant red fruits in the Fall. The buffalo berry, Shepherdia argentea, is another with sexes separate, but the pistillate plants of this also are covered with bright scarlet berries in the Fall.
The little dwarf pussy willow, Salix frisks, and the dusty Zenobia are both excellent, the hitter because it prefers New England’s acid soils and has beautiful drooping bell-like flowers in mid-Spring. The Redleaf rose, Rosa rubrifolia, grows to six feet and has bluish green to purplish red foliage, especially if grown in the full sun.
Finally, the blue leaf honeysuckle, Lonicera korolkowii, and its varieties are excellent subjects to use because of their distinctly bluish-green foliage – markedly different from that of most other green-leaved shrubs with which it is planted.
Some of these plants, especially those with gray foliage, if spotted properly in the garden can give the shrub border a lively and colorful interest throughout the entire Summer.
44659 by Donald Wyman