4 DEPARTMENT CIRCULAR 58, U. S. DEPT. OF AGRICULTURE. 
These factors occur in many and complex combinations, creating 
conditions very trying to horticultural plants; for example, the ex- 
tremely long period during which the soil and roots are frozen 
during the winter virtually amounts to a protracted drought. The 
limiting climatic factors have their most important horticultural 
effect in winterkilling and drought. In the Black Hills conditions 
are comparatively much more favorable than on the Plains, and 
the statements in this circular are not wholly applicable to that 
region. 
SMALL FRUITS. 
Strawberries do well when given winter protection if there is 
enough water to mature the crop. The demand of the crop for water 
at fruiting time is heavy, and in a dry season watering is necessary 
for the best results. Winter mulching is essential. Growing the 
plants in narrow matted rows or in hills appears to be the most 
promising method. Promising varieties are South Dakota, Senator 
Dunlap, and the everbearing varieties Progressive and Minnesota 
No. 1017. 
Red raspberries bear only in favorable wet years. The adoption 
of the hill system and wide spacing are essentials for a crop. An 
extensive planting made at the Mandan station in 1913 has produced 
only one good crop in the five years since that time. That was in 
the third year, 1916. In both 1917 and 1918 the crop was a total 
failure, owing to the lack of sufficient water at fruiting time. All 
varieties require winter protection, such as laying down and covering 
with soil, or mulching. Some promising varieties are Sunbeam, 
Loudon, King, and Minnesota No. 4. 
Black raspberries can not be recommended, as it is very difficult 
to secure a stand. 
Currants are the best of all the small fruits. Many varieties, how- 
ever, are not hardy. The ordinary named black varieties are not 
worth planting. The hardiest and most productive varieties of red 
currants are North Star and London Market. 
Gooseberries have been only moderately successful at the Mandan 
field station. Even such hardy varieties as Houghton, Downing, 
and Carrie suffer winter injury some years if unprotected. Cover- 
ing with soil is hardly practicable when the bushes are large. ‘The 
Houghton is the most promising variety. 
Blackberries and dewberries have been total failures, and should 
not be planted on the northern Great Plains. 
Grapes sometimes do well in town lots or other well-protected 
places. In such places the hardy variety Beta will bear fruit some 
years without a winter covering. In repeated trials since 1914 at 
the Mandan field station all varieties have died from winter injury, 
