152 



THE GARDENER'S MONTHLY 



[May, 



action, by feeding the bud cause the bud to grow 

 and burst into flower independent of the tempe- 

 rature of the atmosphere, if the earth is suffi- 

 ciently warm. If not, why mulch our trees to 

 keep from early bloom. I have peach trees 

 mulched and unmulched standing side by side ; 

 the unmulched are now (March 8,) in bloom, 

 while the mulched show little indications of 

 bloom for many days yet." 



fWe are glad to get letters like this. Such 

 letters show an investigating spirit, which it 

 would profit intelligent horticulture did it pre- 

 vail more extensively. I^o practical gardener 

 would doubt the proposition as presented to "In- 

 quirer," nor do we suppose any teacher of vege- 

 table physiology would question it. For those 

 who have not been in either school it may be 

 useful among many similar observations that 

 might be quoted, to say that it is no unusual 

 thing for gardeners in forcing grape vines, to 

 have a branch of a grape vine run out from a 

 house that is being forced, to one that is cold — 

 that is from a forcing grapery to a cold grapery. 

 The branch in the cold house will remain wholly 

 dormant, while the one in the heat is in leaf and 

 flower, and advancing on towards a fruiting 

 state. Again cases are by no means uncommon 

 where grape houses have the roots out of doors 

 and the branches inside. The temperature of 

 the earth may not be much above the freezing 

 point, but the vines go on to leaf, and fruit just 

 as well when the proper heat is applied to the 

 branches as when the ground containing the 

 roots is exposed to summer heat. Indeed the 

 writer of this once knew of an outside grape 

 border, which was very narrow, perhaps not four 

 feet wide, and about two or three feet above the 

 surrounding level. The grape stems were drawn 

 through a hole in a sixteen-inch stone wall to 

 the house inside. There is every reason to be- 

 lieve that in that severe winter the ground in 

 that border was frozen two or three feet thick, — 

 but the grape vine pushed into leaf and flower 

 on the application of heat with the most perfect 

 Indifference to the frozen roots, so far as any hu- 

 man eye could see. This is among the numer- 

 ous evidences that the practical gardener might 

 adduce. 



The physiologist also has his separate field of 

 reasoning. He sees a willow log, or for that 

 matter many other kinds of log, cut off", lying 

 on the bare ground, without any roots, and yet 

 push buds into leaf, and grow when the warm 

 weather comes, without any roots at all ! | 



Then there are many facts which might be 

 drawn from meteorological observations, which 

 prove the same. For instance the past winter 

 in Pennsylvania. There it has been one of the 

 mildest winters, in a certain sense, on record. 

 The earth has not been frozen much over an inch 

 deep all winter ; while as a genei'al thing it is 

 frozen from one to two feet the whole winter. 

 Tree roots, instead of being for four months sub- 

 jected to a temperature below the freezing 

 point, have probably been favored with a tem- 

 perature of 40^ or 45°. Yet usually the wil- 

 low trees before our window, as we write are 

 quite green by the 21st of March, but on the 

 20th of the month are quite brown, — and no 

 other trees have buds forwarder tl^an they usu- 

 ally have, and the reason is that though the win- 

 ter atmospheric temperature has not been low, 

 neither has it been high. We have had scarcely 

 any warm days. Indeed the atmosphere all win- 

 ter has been decidedly cool if not frosty. In 

 short it is the atmosphere and not the soil that 

 causes the development of the leaf. 



Now as all this must be true, we come to our 

 correspondent's special case. There is no doubt 

 of his facts, for it is a matter of common obser- 

 vation, that an orchard in grass does not bloom 

 so early by a few days as one on cleared ground. 

 But we never heard before that it was because 

 the " ground was warmer," but because the air 

 was cooler. Just as we find a nice grassy field 

 a much pleasanter place to walk over on a hot 

 day than on a dry grassless road. The grass 

 keeps the atmosphere cool as well as the earth. 



It is quite likely if our correspondent would 

 place a thermometer six inches or a foot under 

 ground where the bulk of the roots are, in the 

 mulched and the unmulched cases, he would 

 find the thermometer much the same in both in- 

 stances, — on the other hand if he place a thermo- 

 meter on the trunks of trees "in grass" and 

 trees in "cultivated" ground, and keep the re- 

 cord by a registering thermometer, he will find 

 the atmospheric heat favor the clear ground 

 trees. 



The mere scientific or old-fashioned practical 

 man may think we occupy too much space in 

 " telling nothing new," but the inquiry of our 

 correspondent, as well as of " Inquirer" in the 

 first instance, shows that some of these things 

 have to be gone over again and again, — and in 

 this case, besides the strict scientific value of the 

 question it is one of great practical importance. 

 Ed. G. M.] 



