PHENOLOGY AS AN AID TO HORTICULTUEE. 



53 



plants in the first instance with great care, so that they may fairly 

 represent the climate of the locality in which he resides. For this 

 purpose he is instructed not to enter the date when any plant on the 

 list opens its first flower in his own neighbourhood, but to choose for 

 present and future observation particular specimens which were found to 

 flower neither abnormally early nor abnormally late for that part of the 

 country. A better plan would, no doubt, be to note the date of say half 

 a dozen or more specimens of each of the plants on the list found 

 growing in different parts of any locality, and to enter on the return the 

 average date for these six or more specimens, as the representative date 

 for that particular plant in any one season. But, of course, it would be 

 almost impossible to find enough observers who would take the trouble 

 year after year, or w^ho would have sufficient leisure to make the necessary 

 observations. Therefore the one-plant system has been adopted instead, 

 and, provided the plants are in the first year selected with sufiicient 

 care, almost equally good results are in this way obtained. The instruc- 

 tion is to observe the same individual trees and shrubs each year, and, 

 in the case of herbaceous plants, those growing in the same spots. 



Even the best observations, however, are often found to vary con- 

 siderably for different places in the same part of the country. This 

 arises in a great measure from the variability of our climate, the weather 

 being seldom more than a few^ days in succession in the same mood. For 

 example, it may happen that at the end of a period of very warm weather 

 the selected plant of one observer may have just come into flower, whereas 

 the selected plant of another observer at that particular time may be 

 only on the point of blooming when a change to colder weather takes 

 place, and its flowering is to a greater or less extent delayed. To take an 

 extreme instance, I may state that some years ago the winter aconite, in 

 the part of my garden chosen for observing it, was about to open its first 

 flowers, when there came a long spell of frost and snow, which prevented 

 the blossoms from making any further development for some weeks. The 

 consequence was that, instead of the date for that plant being the earhest 

 I had ever recorded, it was among the very latest. However, with a 

 sufficient number of observers in any large division of the country, like 

 the Midlands, these irregularities are found to equalise themselves, as 

 will be seen in Table B. Then, in order to show how important it is 

 that the plants for observation be carefully selected, I may instance the 

 wood anemone, some roots of which were planted in my garden under a 

 fence facing west, others near the same place but a few yards distant 

 from the fence, others on a piece of rockwork facing south, others under 

 a deodara at the bottom of the rose garden, and the rest behind high 

 shrubs about ten yards away from the deodara. Taking the last five 

 years, their average dates of flow^ering have been respectively March 15, 

 March 25, March 30, April 6, April 9, giving a range between the earliest 

 and latest dates of tw^enty-five days. 



The following particulars, the result of fifteen years' observation, may 

 be of interest as showing the relative forw^ardness of vegetation in 

 different parts of the British Isles — the mean date for the Midlands 

 being taken as representing the average date for the United Kingdom as a 

 whole : 



