This prevents an accumulation of cold air. Sloping sites will also provide good surface water drainage during periods of excessive rainfall. South-facing slopes warm earlier in spring, resulting in earlier cane growth. Raspberries grow best in New Mexico in loam or sandy loam soils with a pH of 6.5-7.5. Such soils should be 2-4 feet deep, well drained, and relatively free of salt.
Raspberries have little tolerance for soils high in either calcium or sodium salts.
Soils should also be free of perennial noxious weeds and nematodes. Perennial weeds and nematodes should be eliminated the year before raspberries are established. Soil improvement programs should be started the year before raspberries are established. Green manure crops of winter wheat, barley, or rye should be planted in fall and turned under the following spring. Barnyard manures can be applied at a rate of 8-12 tons per acre during fall.