Spring is the most suitable season for Platycladus orientalis growth on arid southern mountain slopes. The ideal temperature range is from 10℃ to 17℃. If the species is planted earlier or later than the optimal season, the afforestation survival rate is lowered. Annual growth of juvenile trees exhibits one slow stage and two fast stages. Stage boundaries are the first 10-day period and the mid-summer, in this case mid-July, with growth greater in the earlier stage than in the latter stages. Rainfall may simulate growth but high temperatures restrain growth. That is, although the Platycladus orientalis can endure aridity, growth is promoted more by moisture than optimal temperature. The species responds sensitively to rainfall, usually over 10 days.