WHERE CAN ROSES BE GROWN? 
VCVlF ALL the cultivated plants of our outdoor gardens 
WW'-Sl t ^ le 8 reatest favorite, the most popular, is the Rose. 
jhdLifl M° r e than two million plants have been in recent 
^ITO years imported annually from abroad. But all this 
available supply is cut off by Plant Quarantine No. 37. Roses 
will be worth more intrinsically and for some time the domestic 
supply will likely enough not equal the demand. If we have 
been somewhat careless in how or where the plants were put out, 
it is now time to mend our wavs and plant with reason. Thanks 
to the American Rose Society’s “Annual” there are available 
each year more and more facts about Roses, and the map re- 
produced herewith is calculated to help the inexperienced Rose 
valleys there have been rather decided prolongations of these 
later frost dates northward from the general area, and these have 
been eliminated from the map because those regions are so 
narrow, and the limitations of them were such that we felt it 
would be more misleading to include them than to eliminate 
them. The same holds true with respect to some of the varia- 
tions in the Rocky Mountain region. We have tried in every 
case to make the lines on the safe side. In other words, there 
are points beyond the places indicated where the more tender 
varieties of Roses may succeed. As an example of what I mean : 
There is an area of earlier frost dates on the western shore of 
Lake Michigan, extending to the Wisconsin line, or beyond, but 
I his map, the first of its kind, is of course tentative in its determinations but it shows 
in a general way where the different classes of Roses may be successfully planted 
grower in forewarning him against useless endeavor. The map 
has been prepared in the Bureau of Plant Industry by Dr. W. 
M. Taylor, Prof. L. C. Corbett, and Dr. Walter Van Fleet as 
collaborators with Prof. F. L. Mulford, who writes that the map 
is based upon the Weather Bureau record during the time that 
the various stations have been established. “The area indi- 
cated by horizontal lines covers the region where the average 
date of the last frost is in March, and where tender Roses wouid 
find no frost danger. The stippled area is where the last frost 
comes in April, while the clear area has frosts in May. The 
areas marked by the vertical lines have more or less frost during 
the so-called summer months, or extreme winter temperatures or 
both. The lines between the different areas as a rule rather 
closely follow these frost lines, although at some of the river 
it seemed wise to us to make the limit of the Hybrid Teas about 
Chicago instead of extending the area up along the Lake shore 
in that particular region.” 
Criticisms of the map and the limits it sets are invited by its 
sponsors to the end that it may be made more perfect, and 
attention is called to the fact that there are other factors of 
Rose success beside frost. These are to have the same careful 
consideration, as data regarding them are accumulated; for all 
of which the Society is to be congratulated. This is the sort of 
careful practical work that brings the culture of plants into 
the realms of exact science, and insures continuous and whole- 
some horticultural progress. There is no reason why it should 
not be done with any chosen species, since it is simply a matter 
of patient painstaking and keeping of records. 
