1957 Volume 26 Issue 1 Pages 45-53
The experiments were carried out to search the most suitable season for cutting in ornamental trees and shrubs. Cutting was made inevery month throughout the year, with the plants of 50 kinds.
1. With conifers, spring is believed to be suitable season for cutting and generally cutting of conifers is not made in the other season. In our experiments, it has been found that conifers have rather longer season for cutting and the following plants showed good results in cutting made in fall: Kyaraboku (Taxus cuspidata var. umbraculifera), Yew podocarpus (Podocarpus macrophylla), Common cryptomeria (Cryptomeria japonica), Tatsu-nami-hiba (Chamaecyparis obtusa var. breviramea), Sawara (Chamaecyparis pisifera). Especially Kai-zuka-ibuki (Juniperus chinensis) showed good results in September cutting.
2. With evergreen broad-leaved trees and shrubs, cutting is made in general in summer, and it can be made in spring as well as in fall with plants of a few kinds. So far as our experiments concerned, the following plants showed better results in fall cutting: Sweet bay tree (Laurus nobilis), Narrowleaf firethorn (Pyracantha angustifolia), Common camellia (Camellia japonica var. hortensis), Sasanqua tea (Camellia sasanqua).
3. In deciduous trees, it is believed that cutting is made chiefly in spring with few exception. In our experiments, it 'was showed that cutting is possible in August with cherry tree (Prunus yedoensis) notwithstanding that it has been believ-ed to be impossible. These results may give a hint of the possibility of cutting in the many other plants which have been thought unsuccessful in cutting, by means of cutting before the stems become ripe or hard.
4. In these experiments, many evergreen trees showed better results in cutting made earlier than the time believed suitable in spring and showed good results in fall cuting.
The reason why these experiments showed good results in the season other than the season believed suitable may be due to the following fact: the district where our Experiment Station is located, is warmer and more humid in winter than the central part of Japan. And these relationships are to be studied in the future.