Complex sentence: The finest coffee is typically grown at altitudes of 1200 to 1700 metres, in a shorter winter growing season; the lower quality coffee is typically grown at altitudes below 1200 metres, in a longer growing season that lasts from late summer through to winter.
Split into simpler sentences: The finest coffee is typically grown at altitudes of between 1200 and 1700 metres and in a shorter winter growing season. The lower quality coffee is typically grown at altitudes below 1200 metres and have a longer growing season from late summer through to winter.