THE SUN THE ENEMY.
The interpretation, is that the sun does the damage even. more directly than the frost, though, of course, in association with it. Some years ago, a practical professor of horticulture —the best I ever knew—took me into his garden a day or two after just such an untoward frost. He led me to a plot of early potatoes. Over one half of the bed, the haulms and leaves, were so black and wilted that the plants would have to
start again ; and more than fifty per cent. of the produce was lost. The other half of this same plot looked quite un- damaged. The leaves were fresh, and growth was continuing. The cause was this : on the morning of the frost, before the rays of the sun reached the potatoes, this early-rising professor had watered the leaves of half his crop and left the other half untouched. The water had proved a specific even beyond his expectations. His inference, corroborated by experiment, was that the leaves are killed because when frozen they give out moisture but cannot absorb it soon enough. They die, in short, of transpiration, just as planted-out seedlings may.
Water the leaves and they arc saved. For this sort of reason I attribute the immunity of the Buddleia and laburnum on the north-looking wall to absence of the sun's rays. It is, of course, a fact well known to expert growers that some of the newer importations from China do best with a north aspect. not because they are hardier than others, but because they are more tender.